+publisher:"Texas A&M University" +contributor:("Holtzapple, Mark")

Texas A&M University

1. Berman, Ilan Clifford Abraham. Designing a System for Upgrading of Heavy Crude Oils Through Electron Beam Treatment.

Degree: MS, Mechanical Engineering, 2015, Texas A&M University

URL: http://hdl.handle.net/1969.1/174211

► Low-quality crude oil reserves require prohibitively high energy costs to extract and transport. The extreme viscosity and impurities of these oils prevents them from being… (more)

Subjects/Keywords: Crude Oil; Heavy; Sour; Upgrading; Electron Beam; System Design

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APA (6^th Edition):

Berman, I. C. A. (2015). Designing a System for Upgrading of Heavy Crude Oils Through Electron Beam Treatment. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/174211

Chicago Manual of Style (16^th Edition):

Berman, Ilan Clifford Abraham. “Designing a System for Upgrading of Heavy Crude Oils Through Electron Beam Treatment.” 2015. Masters Thesis, Texas A&M University. Accessed April 10, 2021. http://hdl.handle.net/1969.1/174211.

MLA Handbook (7^th Edition):

Berman, Ilan Clifford Abraham. “Designing a System for Upgrading of Heavy Crude Oils Through Electron Beam Treatment.” 2015. Web. 10 Apr 2021.

Vancouver:

Berman ICA. Designing a System for Upgrading of Heavy Crude Oils Through Electron Beam Treatment. [Internet] [Masters thesis]. Texas A&M University; 2015. [cited 2021 Apr 10]. Available from: http://hdl.handle.net/1969.1/174211.

Council of Science Editors:

Berman ICA. Designing a System for Upgrading of Heavy Crude Oils Through Electron Beam Treatment. [Masters Thesis]. Texas A&M University; 2015. Available from: http://hdl.handle.net/1969.1/174211

Texas A&M University

2. Roy, Samarpita. Effect of Extraction Using Ion-Exchange Resins on Batch Mixed-Acid Fermentations.

Degree: MS, Civil Engineering, 2014, Texas A&M University

URL: http://hdl.handle.net/1969.1/174665

► Biofuels are increasingly gaining importance as an energy source. The MixAlco® process is a biomass-to-energy technology that uses mixed cultures of microorganisms to convert biomass… (more)

▼ Biofuels are increasingly gaining importance as an energy source. The MixAlco® process is a biomass-to-energy technology that uses mixed cultures of microorganisms to convert biomass to mixed carboxylic acids. Using a buffer, the acids are neutralized to their corresponding salts, which are recovered from the fermentation broth. Finally, the carboxylate salts are chemically converted to mixed-alcohol fuels, hydrocarbon fuels (gasoline, jet fuel, etc.), and industrial chemicals. To be a viable alternative to fossil fuels, biofuels must be economical, provide a net energy gain, and be easily produced in large quantities. Previous studies have shown that as product concentration increases, the fermenting microorganisms are increasingly inhibited, which lowers production rates and yield. Maintaining low carboxylate salt concentration in fermentors reduces product inhibition and allows microorganisms to function efficiently and increase biomass digestion. In this study, anion-exchange resin (Amberlite IRA-67) was used to extract carboxylate salts from fermentation broth and thereby maintain near-neutral pH. Three different batch fermentations were performed using the following substrates: α-cellulose powder, shredded office paper, and lime-pretreated corn stover. It was observed that periodic extraction of carboxylate salts reduced product inhibition and thereby increased acid production in the fermentors. For all substrates, fermentors that employed an ion-exchange resin column for acid extraction had higher yield than fermentors where magnesium carbonate (MgCO_(3)) was used as a buffer to maintain pH. The yield expressed as gram total carboxylic acid produced per gram non-acid volatile solids (NAVS) fed were 0.15 (MgCO_(3) control) and 0.35 for α-cellulose substrate, 0.24 (MgCO_(3) control) and 0.37 for paper substrate, and 0.20 (MgCO_(3) control) and 0.35 for lime-pretreated corn stover. Other fermentation parameters such as conversion and selectivity also improved with periodic carboxylic acid extraction. The production of high-molecular-weight acids significantly increased for fermentors with IR extraction. This is important to the MixAlco® process because it generates high-energy products. Advisors/Committee Members: Batchelor, Bill (advisor), Holtzapple, Mark (advisor), Ying, Qi (committee member).

Subjects/Keywords: MixAlco process; ion exchange resin; fermentation; mixed-acid

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Roy, S. (2014). Effect of Extraction Using Ion-Exchange Resins on Batch Mixed-Acid Fermentations. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/174665

Chicago Manual of Style (16^th Edition):

Roy, Samarpita. “Effect of Extraction Using Ion-Exchange Resins on Batch Mixed-Acid Fermentations.” 2014. Masters Thesis, Texas A&M University. Accessed April 10, 2021. http://hdl.handle.net/1969.1/174665.

MLA Handbook (7^th Edition):

Roy, Samarpita. “Effect of Extraction Using Ion-Exchange Resins on Batch Mixed-Acid Fermentations.” 2014. Web. 10 Apr 2021.

Vancouver:

Roy S. Effect of Extraction Using Ion-Exchange Resins on Batch Mixed-Acid Fermentations. [Internet] [Masters thesis]. Texas A&M University; 2014. [cited 2021 Apr 10]. Available from: http://hdl.handle.net/1969.1/174665.

Council of Science Editors:

Roy S. Effect of Extraction Using Ion-Exchange Resins on Batch Mixed-Acid Fermentations. [Masters Thesis]. Texas A&M University; 2014. Available from: http://hdl.handle.net/1969.1/174665

Texas A&M University

3. Roy, Samarpita. Effect of Extraction Using Ion-Exchange Resins on Batch Mixed-Acid Fermentations.

Degree: MS, Civil Engineering, 2014, Texas A&M University

URL: http://hdl.handle.net/1969.1/174664

► Biofuels are increasingly gaining importance as an energy source. The MixAlco® process is a biomass-to-energy technology that uses mixed cultures of microorganisms to convert biomass… (more)

▼ Biofuels are increasingly gaining importance as an energy source. The MixAlco® process is a biomass-to-energy technology that uses mixed cultures of microorganisms to convert biomass to mixed carboxylic acids. Using a buffer, the acids are neutralized to their corresponding salts, which are recovered from the fermentation broth. Finally, the carboxylate salts are chemically converted to mixed-alcohol fuels, hydrocarbon fuels (gasoline, jet fuel, etc.), and industrial chemicals. To be a viable alternative to fossil fuels, biofuels must be economical, provide a net energy gain, and be easily produced in large quantities. Previous studies have shown that as product concentration increases, the fermenting microorganisms are increasingly inhibited, which lowers production rates and yield. Maintaining low carboxylate salt concentration in fermentors reduces product inhibition and allows microorganisms to function efficiently and increase biomass digestion. In this study, anion-exchange resin (Amberlite IRA-67) was used to extract carboxylate salts from fermentation broth and thereby maintain near-neutral pH. Three different batch fermentations were performed using the following substrates: α-cellulose powder, shredded office paper, and lime-pretreated corn stover. It was observed that periodic extraction of carboxylate salts reduced product inhibition and thereby increased acid production in the fermentors. For all substrates, fermentors that employed an ion-exchange resin column for acid extraction had higher yield than fermentors where magnesium carbonate (MgCO_(3)) was used as a buffer to maintain pH. The yield expressed as gram total carboxylic acid produced per gram non-acid volatile solids (NAVS) fed were 0.15 (MgCO_(3) control) and 0.35 for α-cellulose substrate, 0.24 (MgCO_(3) control) and 0.37 for paper substrate, and 0.20 (MgCO_(3) control) and 0.35 for lime-pretreated corn stover. Other fermentation parameters such as conversion and selectivity also improved with periodic carboxylic acid extraction. The production of high-molecular-weight acids significantly increased for fermentors with IR extraction. This is important to the MixAlco® process because it generates high-energy products. Advisors/Committee Members: Batchelor, Bill (advisor), Holtzapple, Mark (advisor), Ying, Qi (committee member).

Subjects/Keywords: MixAlco process; ion exchange resin; fermentation; mixed-acid

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Roy, S. (2014). Effect of Extraction Using Ion-Exchange Resins on Batch Mixed-Acid Fermentations. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/174664

Chicago Manual of Style (16^th Edition):

Roy, Samarpita. “Effect of Extraction Using Ion-Exchange Resins on Batch Mixed-Acid Fermentations.” 2014. Masters Thesis, Texas A&M University. Accessed April 10, 2021. http://hdl.handle.net/1969.1/174664.

MLA Handbook (7^th Edition):

Roy, Samarpita. “Effect of Extraction Using Ion-Exchange Resins on Batch Mixed-Acid Fermentations.” 2014. Web. 10 Apr 2021.

Vancouver:

Roy S. Effect of Extraction Using Ion-Exchange Resins on Batch Mixed-Acid Fermentations. [Internet] [Masters thesis]. Texas A&M University; 2014. [cited 2021 Apr 10]. Available from: http://hdl.handle.net/1969.1/174664.

Council of Science Editors:

Roy S. Effect of Extraction Using Ion-Exchange Resins on Batch Mixed-Acid Fermentations. [Masters Thesis]. Texas A&M University; 2014. Available from: http://hdl.handle.net/1969.1/174664

Texas A&M University

4. Roy, Samarpita. Effect of Extraction Using Ion-Exchange Resins on Batch Mixed-Acid Fermentations.

Degree: MS, Civil Engineering, 2014, Texas A&M University

URL: http://hdl.handle.net/1969.1/174666

► Biofuels are increasingly gaining importance as an energy source. The MixAlco® process is a biomass-to-energy technology that uses mixed cultures of microorganisms to convert biomass… (more)

▼ Biofuels are increasingly gaining importance as an energy source. The MixAlco® process is a biomass-to-energy technology that uses mixed cultures of microorganisms to convert biomass to mixed carboxylic acids. Using a buffer, the acids are neutralized to their corresponding salts, which are recovered from the fermentation broth. Finally, the carboxylate salts are chemically converted to mixed-alcohol fuels, hydrocarbon fuels (gasoline, jet fuel, etc.), and industrial chemicals. To be a viable alternative to fossil fuels, biofuels must be economical, provide a net energy gain, and be easily produced in large quantities. Previous studies have shown that as product concentration increases, the fermenting microorganisms are increasingly inhibited, which lowers production rates and yield. Maintaining low carboxylate salt concentration in fermentors reduces product inhibition and allows microorganisms to function efficiently and increase biomass digestion. In this study, anion-exchange resin (Amberlite IRA-67) was used to extract carboxylate salts from fermentation broth and thereby maintain near-neutral pH. Three different batch fermentations were performed using the following substrates: α-cellulose powder, shredded office paper, and lime-pretreated corn stover. It was observed that periodic extraction of carboxylate salts reduced product inhibition and thereby increased acid production in the fermentors. For all substrates, fermentors that employed an ion-exchange resin column for acid extraction had higher yield than fermentors where magnesium carbonate (MgCO_(3)) was used as a buffer to maintain pH. The yield expressed as gram total carboxylic acid produced per gram non-acid volatile solids (NAVS) fed were 0.15 (MgCO_(3) control) and 0.35 for α-cellulose substrate, 0.24 (MgCO_(3) control) and 0.37 for paper substrate, and 0.20 (MgCO_(3) control) and 0.35 for lime-pretreated corn stover. Other fermentation parameters such as conversion and selectivity also improved with periodic carboxylic acid extraction. The production of high-molecular-weight acids significantly increased for fermentors with IR extraction. This is important to the MixAlco® process because it generates high-energy products. Advisors/Committee Members: Batchelor, Bill (advisor), Holtzapple, Mark (advisor), Ying, Qi (committee member).

Subjects/Keywords: MixAlco process; ion exchange resin; fermentation; mixed-acid

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Roy, S. (2014). Effect of Extraction Using Ion-Exchange Resins on Batch Mixed-Acid Fermentations. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/174666

Chicago Manual of Style (16^th Edition):

Roy, Samarpita. “Effect of Extraction Using Ion-Exchange Resins on Batch Mixed-Acid Fermentations.” 2014. Masters Thesis, Texas A&M University. Accessed April 10, 2021. http://hdl.handle.net/1969.1/174666.

MLA Handbook (7^th Edition):

Roy, Samarpita. “Effect of Extraction Using Ion-Exchange Resins on Batch Mixed-Acid Fermentations.” 2014. Web. 10 Apr 2021.

Vancouver:

Roy S. Effect of Extraction Using Ion-Exchange Resins on Batch Mixed-Acid Fermentations. [Internet] [Masters thesis]. Texas A&M University; 2014. [cited 2021 Apr 10]. Available from: http://hdl.handle.net/1969.1/174666.

Council of Science Editors:

Roy S. Effect of Extraction Using Ion-Exchange Resins on Batch Mixed-Acid Fermentations. [Masters Thesis]. Texas A&M University; 2014. Available from: http://hdl.handle.net/1969.1/174666

Texas A&M University

5. Honang, Hanniel Jouvain. Reactor Physics Analysis of Air-Cooled Nuclear System.

Degree: MS, Nuclear Engineering, 2016, Texas A&M University

URL: http://hdl.handle.net/1969.1/156990

► The design of SACRé (Small Air-Cooled Reactor) fixated on evaluations of air as a potential coolant. The assessment offered in this thesis focused on reactor… (more)

▼ The design of SACRé (Small Air-Cooled Reactor) fixated on evaluations of air as a potential coolant. The assessment offered in this thesis focused on reactor physic analyses, and materials review and incorporation in a system defined by a highly corrosive environment. The oxidizing nature of air at high-temperature warrants the need to examine and compare materials for their oxidation temperature, their melting and boiling temperature, and their thermal conductivity. Material choices for the fuel, the cladding, the system’s casing/structural material and the reflector were evaluated in this study. Survey of materials and literature lead to the selection of six different cladding materials which are FeCrAl, APMT, Inconel 718 and stainless steel of type 304, 316 and 310. A review of their thermal properties, for a high oxidation temperature and melting temperature and the exhibition of a hard neutron spectrum lead to the selection of APMT steel material. This material was not only be selected as the fuel cladding but also as a casing for reflector and shielding materials. The design of this 600 MWth system was investigated considering reflector materials for fast spectrum. Lead-based reflectors (lead bismuth eutectic, lead oxide and pure lead), magnesium-based reflectors (magnesium oxide and magnesium aluminum oxide), and aluminum oxide reflectors were evaluated in this thesis. The design configurations were compared to determine those which provide a hard neutron spectrum, an economically appropriate cycle length, a low breeding ratio and the least amount of neutrons escaping the reactor. The assessments of these notable characteristics lead to the selection of MgO reflector. This reflector allowed the system to operate for six years, for a corresponding burnup of 85 MWd/kgU. The thermal setting of 875°C fuel temperature and 575°C of coolant and structural temperature promoted the design of a system with a fuel volume fraction smaller than that of the coolant volume fraction (40.28% - 45.01% respectively). This configuration was promoted favorable over an active core with a fuel volume fraction higher than or equal to the coolant volume fraction because of some thermal properties of air like a small thermal conductivity, specific heat and density. Advisors/Committee Members: Tsvetkov, Pavel (advisor), Holtzapple, Mark (committee member), McDeavitt, Sean (committee member).

Subjects/Keywords: air; gas; reactor; modular; MCNP; Argon; oxidation; reflector; burnup; leakage; Uranium; cycle; fuel; assembly

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Honang, H. J. (2016). Reactor Physics Analysis of Air-Cooled Nuclear System. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/156990

Chicago Manual of Style (16^th Edition):

Honang, Hanniel Jouvain. “Reactor Physics Analysis of Air-Cooled Nuclear System.” 2016. Masters Thesis, Texas A&M University. Accessed April 10, 2021. http://hdl.handle.net/1969.1/156990.

MLA Handbook (7^th Edition):

Honang, Hanniel Jouvain. “Reactor Physics Analysis of Air-Cooled Nuclear System.” 2016. Web. 10 Apr 2021.

Vancouver:

Honang HJ. Reactor Physics Analysis of Air-Cooled Nuclear System. [Internet] [Masters thesis]. Texas A&M University; 2016. [cited 2021 Apr 10]. Available from: http://hdl.handle.net/1969.1/156990.

Council of Science Editors:

Honang HJ. Reactor Physics Analysis of Air-Cooled Nuclear System. [Masters Thesis]. Texas A&M University; 2016. Available from: http://hdl.handle.net/1969.1/156990

Texas A&M University

6. Vincent George, John Kennady. Theoretical and Experimental Study of Biobased Succinic Acid Production.

Degree: MS, Energy, 2017, Texas A&M University

URL: http://hdl.handle.net/1969.1/165922

► Biomass based succinic acid is gaining increasing interest as a potential platform chemical for replacing a large petroleum-based bulk chemical market. Biomass as a renewable… (more)

▼ Biomass based succinic acid is gaining increasing interest as a potential platform chemical for replacing a large petroleum-based bulk chemical market. Biomass as a renewable resource has proved the economic and sustainable potential to produce succinic acid by fermentation method. Biobased succinic acid has yet faced with the challenge of becoming competitive with petrochemical method because of its higher production cost. To lower the production cost, extensive research efforts have been undertaken in upstream technology that involves strain development via metabolic engineering, and downstream technology that aims to improve efficiency of purification method. Many research studies have focused on either one of two technological areas, with little interest on interaction between them. This present work integrates the processing steps from upstream and downstream technologies using a systematic approach and presents an optimal production pathway from a large number of possible process configurations. The development of such a process pathway involves selection of bioproducts, feedstock, pre-treatment technology, microorganism and product separation method. Performance criteria such as titre, rate, yield and minimum production cost, express the optimality of production pathway. Optimization study indicates that succinic acid seems to be the most promising bioproduct among all other bioproducts. Corn stover is the suitable feedstock to produce succinic acid. Based on the findings from optimization study, experimental work was performed with an aim of achieving better performance criteria than it is reported in literature. This work selected corn stover as feedstock, and a bacterium called, Basfia succiniciproducens for converting corn stover-derived glucose into succinic acid. To date, no deliberate experiment has been done on this bacterium to improve succinic acid production, despite its promising features. Highest succinic acid yield of 18 g/100g total sugar (glucose plus xylose) was observed in this experiment. Genetically modified strain of the bacterium reported a much higher yield of 71 gm succinic acid/ 100gm of glucose. Advisors/Committee Members: Capareda, Sergio (advisor), Holtzapple, Mark (committee member), El Halwagi, Mahmoud (committee member).

Subjects/Keywords: Biomass based succinic acid; platform chemicals; microbial fermentation; green technology; titre; yield; production rate; genetic modification; petrochemical method

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APA (6^th Edition):

Vincent George, J. K. (2017). Theoretical and Experimental Study of Biobased Succinic Acid Production. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/165922

Chicago Manual of Style (16^th Edition):

Vincent George, John Kennady. “Theoretical and Experimental Study of Biobased Succinic Acid Production.” 2017. Masters Thesis, Texas A&M University. Accessed April 10, 2021. http://hdl.handle.net/1969.1/165922.

MLA Handbook (7^th Edition):

Vincent George, John Kennady. “Theoretical and Experimental Study of Biobased Succinic Acid Production.” 2017. Web. 10 Apr 2021.

Vancouver:

Vincent George JK. Theoretical and Experimental Study of Biobased Succinic Acid Production. [Internet] [Masters thesis]. Texas A&M University; 2017. [cited 2021 Apr 10]. Available from: http://hdl.handle.net/1969.1/165922.

Council of Science Editors:

Vincent George JK. Theoretical and Experimental Study of Biobased Succinic Acid Production. [Masters Thesis]. Texas A&M University; 2017. Available from: http://hdl.handle.net/1969.1/165922

Texas A&M University

7. Babbar, Yogesh. Wind Tunnel and Flight Testing of Active Flow Control on a UAV.

Degree: MS, Aerospace Engineering, 2011, Texas A&M University

URL: http://hdl.handle.net/1969.1/ETD-TAMU-2010-05-8003

► Active flow control has been extensively explored in wind tunnel studies but successful in-flight implementation of an active flow control technology still remains a challenge.… (more)

Subjects/Keywords: UAV; active flow control; Extra 330; pulsed blowing; fluidic actuator; flight testing; wind tunnel testing; ailerons

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Babbar, Y. (2011). Wind Tunnel and Flight Testing of Active Flow Control on a UAV. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2010-05-8003

Chicago Manual of Style (16^th Edition):

Babbar, Yogesh. “Wind Tunnel and Flight Testing of Active Flow Control on a UAV.” 2011. Masters Thesis, Texas A&M University. Accessed April 10, 2021. http://hdl.handle.net/1969.1/ETD-TAMU-2010-05-8003.

MLA Handbook (7^th Edition):

Babbar, Yogesh. “Wind Tunnel and Flight Testing of Active Flow Control on a UAV.” 2011. Web. 10 Apr 2021.

Vancouver:

Babbar Y. Wind Tunnel and Flight Testing of Active Flow Control on a UAV. [Internet] [Masters thesis]. Texas A&M University; 2011. [cited 2021 Apr 10]. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2010-05-8003.

Council of Science Editors:

Babbar Y. Wind Tunnel and Flight Testing of Active Flow Control on a UAV. [Masters Thesis]. Texas A&M University; 2011. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2010-05-8003

Texas A&M University

8. Johnson, Shalom. Development of a Pulse Modulator for Active Flow Control in Turbomachinery.

Degree: MS, Aerospace Engineering, 2011, Texas A&M University

URL: http://hdl.handle.net/1969.1/ETD-TAMU-2010-05-8035

► In todays highly maneuverable jet aircraft designs, aircraft are required to have a propulsion system that can operate during sudden accelerations and rapid changes in… (more)

Subjects/Keywords: stall suppression; Turbomachinery; axial compressor; oscillatory blowing

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APA (6^th Edition):

Johnson, S. (2011). Development of a Pulse Modulator for Active Flow Control in Turbomachinery. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2010-05-8035

Chicago Manual of Style (16^th Edition):

Johnson, Shalom. “Development of a Pulse Modulator for Active Flow Control in Turbomachinery.” 2011. Masters Thesis, Texas A&M University. Accessed April 10, 2021. http://hdl.handle.net/1969.1/ETD-TAMU-2010-05-8035.

MLA Handbook (7^th Edition):

Johnson, Shalom. “Development of a Pulse Modulator for Active Flow Control in Turbomachinery.” 2011. Web. 10 Apr 2021.

Vancouver:

Johnson S. Development of a Pulse Modulator for Active Flow Control in Turbomachinery. [Internet] [Masters thesis]. Texas A&M University; 2011. [cited 2021 Apr 10]. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2010-05-8035.

Council of Science Editors:

Johnson S. Development of a Pulse Modulator for Active Flow Control in Turbomachinery. [Masters Thesis]. Texas A&M University; 2011. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2010-05-8035

Texas A&M University

9. Smith, Aaron Douglas. Pilot-Scale Fermentation and Laboratory Nutrient Studies on Mixed-Acid Fermentation.

Degree: PhD, Chemical Engineering, 2011, Texas A&M University

URL: http://hdl.handle.net/1969.1/ETD-TAMU-2011-05-9193

► Via mixed-culture fermentation, the MixAlcoTM produces carboxylic acids, which are chemically converted into industrial chemicals and hydrocarbon fuels. Using pilot fermentation data, The Continuum Particle… (more)

▼ Via mixed-culture fermentation, the MixAlcoTM produces carboxylic acids, which are chemically converted into industrial chemicals and hydrocarbon fuels. Using pilot fermentation data, The Continuum Particle Distribution Model (CPDM) overestimated acid concentration (30–90% error) but more closely estimated conversion (<15% error). Incorporating the effect of air into the model reduced the absolute error of all predictions by >50%. To analyze fermentation data with semi-continuous streams, the Slope method calculates the average flowrate of material from the slope of the moving cumulative sum with respect to time. Although the Slope method does not significantly improve accuracy, it dramatically reduces error compared to traditional techniques (>40% vs. <2%). Nutrients are essential for microbial growth and metabolism. For a four-bottle fermentation train, five nutrient contacting patterns (single-point nutrient addition to Fermentors F1, F2, F3, F4, and multi-point parallel addition) were investigated. Compared to the traditional nutrient contacting method (all nutrients fed to F1), the near-optimal feeding strategies improved exit yield, culture yield, process yield, exit acetate-equivalent yield, conversion, and total acid productivity by approximately 31%, 39%, 46%, 31%, 100%, and 19%, respectively. To estimate nitrogen concentration profiles, a segregated-nitrogen model uses separate mass balances for solid- and liquid-phase nitrogen; the nitrogen reaction flux between phases is assumed to be zero. Using five fermentation trains, each with a different nutrient contacting pattern, the model predictions capture basic behavior; therefore, it is a reasonable tool for estimating and controlling nitrogen profiles. To determine the optimal scenario for mixed-acid fermentations, an array of batch fermentations was performed that independently varied the C/N ratio and the blend of carbohydrate (office paper) and nutrient (wet chicken manure (CM)). Reactant was defined as non-acid volatile solids (NAVS). C/N ratios were based on non-acid carbon (CNA). A blend of 93% paper and 7% wet CM (dry basis) with a C/N ratio of 37 g CNA/g N had the highest culture yield (0.21 g acidproduced/g NAVSinitial), total acid productivity (0.84 g acidproduced/(Lliq·d)), and conversion (0.43 g NAVSconsumed/g NAVSinitial). Advisors/Committee Members: Holtzapple, Mark T. (advisor), Glover, Charles (committee member), Hall, Kenneth (committee member), Capareda, Sergio (committee member).

Subjects/Keywords: Mixed-acid fermentation; C/N Ratio; nitrogen; nitrogen model; CPDM; pilot fermentation

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APA (6^th Edition):

Smith, A. D. (2011). Pilot-Scale Fermentation and Laboratory Nutrient Studies on Mixed-Acid Fermentation. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2011-05-9193

Chicago Manual of Style (16^th Edition):

Smith, Aaron Douglas. “Pilot-Scale Fermentation and Laboratory Nutrient Studies on Mixed-Acid Fermentation.” 2011. Doctoral Dissertation, Texas A&M University. Accessed April 10, 2021. http://hdl.handle.net/1969.1/ETD-TAMU-2011-05-9193.

MLA Handbook (7^th Edition):

Smith, Aaron Douglas. “Pilot-Scale Fermentation and Laboratory Nutrient Studies on Mixed-Acid Fermentation.” 2011. Web. 10 Apr 2021.

Vancouver:

Smith AD. Pilot-Scale Fermentation and Laboratory Nutrient Studies on Mixed-Acid Fermentation. [Internet] [Doctoral dissertation]. Texas A&M University; 2011. [cited 2021 Apr 10]. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2011-05-9193.

Council of Science Editors:

Smith AD. Pilot-Scale Fermentation and Laboratory Nutrient Studies on Mixed-Acid Fermentation. [Doctoral Dissertation]. Texas A&M University; 2011. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2011-05-9193

Texas A&M University

10. Foucault, Lucas Jose. Anaerobic Co-digestion of Chicken Processing Wastewater and Crude Glycerol from Biodiesel.

Degree: MS, Biological and Agricultural Engineering, 2011, Texas A&M University

URL: http://hdl.handle.net/1969.1/ETD-TAMU-2011-08-9847

► The main objective of this thesis was to study the anaerobic digestion (AD) of wastewater from a chicken processing facility and of crude glycerol from… (more)

Subjects/Keywords: Anaerobic digestion; co-digestion; glycerol; glycerin; methane; biogas; chicken processing wastewater

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APA (6^th Edition):

Foucault, L. J. (2011). Anaerobic Co-digestion of Chicken Processing Wastewater and Crude Glycerol from Biodiesel. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2011-08-9847

Chicago Manual of Style (16^th Edition):

Foucault, Lucas Jose. “Anaerobic Co-digestion of Chicken Processing Wastewater and Crude Glycerol from Biodiesel.” 2011. Masters Thesis, Texas A&M University. Accessed April 10, 2021. http://hdl.handle.net/1969.1/ETD-TAMU-2011-08-9847.

MLA Handbook (7^th Edition):

Foucault, Lucas Jose. “Anaerobic Co-digestion of Chicken Processing Wastewater and Crude Glycerol from Biodiesel.” 2011. Web. 10 Apr 2021.

Vancouver:

Foucault LJ. Anaerobic Co-digestion of Chicken Processing Wastewater and Crude Glycerol from Biodiesel. [Internet] [Masters thesis]. Texas A&M University; 2011. [cited 2021 Apr 10]. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2011-08-9847.

Council of Science Editors:

Foucault LJ. Anaerobic Co-digestion of Chicken Processing Wastewater and Crude Glycerol from Biodiesel. [Masters Thesis]. Texas A&M University; 2011. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2011-08-9847

Texas A&M University

11. Darvekar, Pratik. Assessment of Shock Pretreatment of Corn Stover Using the Carboxylate Platform.

Degree: PhD, Chemical Engineering, 2016, Texas A&M University

URL: http://hdl.handle.net/1969.1/157090

► Fuels and chemicals from lignocellulosic biomass, a renewable energy source, is an attractive solution to meet ever-increasing global energy needs and reduce global climate change.… (more)

▼ Fuels and chemicals from lignocellulosic biomass, a renewable energy source, is an attractive solution to meet ever-increasing global energy needs and reduce global climate change. In the biochemical conversion of lignocellulose, the first and the most expensive step is pretreatment. This study focuses on the efficacy of shock pretreatment, a mechanical process that uses a shockwave to alter the biomass structure. Corn stover was pretreated with lime and shock. The two pretreatments (lime-only and lime + shock) were evaluated using enzymatic hydrolysis, batch mixed-culture fermentations, and continuous countercurrent mixed-culture fermentation. In a 120-h enzymatic hydrolysis, shock pretreatment increased the glucan digestibility of SLP (submerged lime pretreatment) corn stover by 3.5% and OLP (oxidative lime pretreatment) corn stover by 2.5%. The continuum particle distribution model (CPDM) was used to simulate a four-stage continuous countercurrent mixed-culture fermentation using empirical rate models obtained from simple batch experiments. The CPDM model determined that lime + shock pretreatment increased the total carboxylic acids yield by 28.5% over lime-only pretreatment in a countercurrent fermentation with a VSLR (volatile solids loading rate) of 12 g/(L·day) and LRT (liquid retention time) of 30 days. In a semi-continuous countercurrent fermentation performed in the laboratory for 112 days with a VSLR of 1.875 g/(L·day) and LRT of 16 days, lime + shock pretreatment increased the total carboxylic acids yield by 14.8%. The experimental results matched closely with CPDM models predictions (4.05% error). Calcium carbonate and magnesium carbonate were compared as buffers for mixed-culture fermentations of lime and lime + shock pretreated corn stover. Batch fermentations at five different substrate loadings of lime and lime + shock pretreated corn stover were performed with MgCO3 and CaCO3 buffer. In batch fermentations with 100 g/L substrate, the carboxylic acid production more than doubled (2.7 times for lime and 2.6 times for lime + shock corn stover) when MgCO3 buffer was used. In addition, CPDM was used to simulate and predict the performance of a four-stage countercurrent fermentation using MgCO3 and CaCO3 buffer. CPDM predicts that in a four-stage countercurrent fermentation with a high volatile solids loading rate (VSLR 12 g/(L·day)) and low liquid residence time (LRT 10 day), using MgCO3 buffer will yield a carboxylic acid concentration of 26.1 g/L, a 22.5% increase over CaCO3 buffer. Adding shock to lime pretreatment increased the yields at all substrate loadings in both batch fermentations and CPDM model predictions. The effect of hydrogen and carbon dioxide gas concentrations in the headspace of mixed-culture fermentations was studied. Using H2:CO2 (1:1) at 1 atm in the fermenter headspace increased the total carboxylic acids by 37%. Using CO2-only in the headspace reduced the total acids by 4%, but shifted the acid spectrum toward high-molecular-weight acids. Advisors/Committee Members: Holtzapple, Mark (advisor), El-Halwagi, Mahmoud (committee member), Glover, Charles (committee member), Nikolov, Zivko (committee member).

Subjects/Keywords: Lignocellulose; Enzymatic Hydrolysis; Mixed-Culture Fermentations; Shock Pretreatment; Continuum Particle Distribution Modeling (CPDM)

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APA (6^th Edition):

Darvekar, P. (2016). Assessment of Shock Pretreatment of Corn Stover Using the Carboxylate Platform. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/157090

Chicago Manual of Style (16^th Edition):

Darvekar, Pratik. “Assessment of Shock Pretreatment of Corn Stover Using the Carboxylate Platform.” 2016. Doctoral Dissertation, Texas A&M University. Accessed April 10, 2021. http://hdl.handle.net/1969.1/157090.

MLA Handbook (7^th Edition):

Darvekar, Pratik. “Assessment of Shock Pretreatment of Corn Stover Using the Carboxylate Platform.” 2016. Web. 10 Apr 2021.

Vancouver:

Darvekar P. Assessment of Shock Pretreatment of Corn Stover Using the Carboxylate Platform. [Internet] [Doctoral dissertation]. Texas A&M University; 2016. [cited 2021 Apr 10]. Available from: http://hdl.handle.net/1969.1/157090.

Council of Science Editors:

Darvekar P. Assessment of Shock Pretreatment of Corn Stover Using the Carboxylate Platform. [Doctoral Dissertation]. Texas A&M University; 2016. Available from: http://hdl.handle.net/1969.1/157090

Texas A&M University

12. Mroue, Ahmed Mohamad. Energy Portfolio Assessment Tool (EPAT): Sustainable Energy Planning Using the WEF Nexus Approach - Texas Case Study.

Degree: MS, Energy, 2017, Texas A&M University

URL: http://hdl.handle.net/1969.1/165861

► The future energy portfolio at the national and subnational levels should consider its impact on water resources and environment. Although energy resources are the main… (more)

▼ The future energy portfolio at the national and subnational levels should consider its impact on water resources and environment. Although energy resources are the main contributors to the national economic growth, these resources must not exploit other primary natural resources. A study of the connections between energy and natural systems, such as water, environment and land, is required prior to proceeding to energy development. Policy makers are in need of a tool quantifying the interlinkages across energy, water and the environment, while demonstrating the consequent trade-offs across the nexus systems. The Energy Portfolio Assessment Tool (EPAT) is a tool enabling the user to create different energy portfolio scenarios with various energy and electricity sources, and evaluate the scenario’s sustainability environmentally and economically. The Water-Energy-Food nexus systematic approach is the foundation of the EPAT framework. Texas is a suitable geographical region to study and assess the current and future implications of energy portfolios. The research evaluates the impact of the current and projected Texas energy portfolios on water and the environment, taking into consideration production, generation and production change. The three scenarios are: Reference Case - 2015, CPP with Energy Reference Case - 2030, and No CPP with Energy Reference Case - 2030. In the presence of the CPP, total water withdrawal is expected to decrease significantly, while total water consumption is projected to experience a shy decrease due to the increase in water consumption in electricity generation caused by the new electricity mix. The CPP is successful in decreasing emissions, but is accompanied by tradeoffs, such as increasing water consumption and land use by electricity generation. The absence of the CPP will lead to an extreme surge in total water withdrawn, consumed and emissions. Therefore, conservation policies should move from the silo to the nexus mentality to avoid unintended consequences as improving one part of the nexus could end up worsening the other parts. Advisors/Committee Members: Mohtar, Rabi H (advisor), Holtzapple, Mark T (committee member), Pistikopoulos, Efstratios N (committee member).

Subjects/Keywords: Energy; Policy; Renewable Energy; Water; Sustainable Energy; Energy-Water Nexus; Electric Power Generation; Power Plant Cooling; Oil and Gas Production; Hydraulic Fracturing; Water-Energy-Food Nexus; Energy Portfolio; Energy Planning

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APA (6^th Edition):

Mroue, A. M. (2017). Energy Portfolio Assessment Tool (EPAT): Sustainable Energy Planning Using the WEF Nexus Approach - Texas Case Study. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/165861

Chicago Manual of Style (16^th Edition):

Mroue, Ahmed Mohamad. “Energy Portfolio Assessment Tool (EPAT): Sustainable Energy Planning Using the WEF Nexus Approach - Texas Case Study.” 2017. Masters Thesis, Texas A&M University. Accessed April 10, 2021. http://hdl.handle.net/1969.1/165861.

MLA Handbook (7^th Edition):

Mroue, Ahmed Mohamad. “Energy Portfolio Assessment Tool (EPAT): Sustainable Energy Planning Using the WEF Nexus Approach - Texas Case Study.” 2017. Web. 10 Apr 2021.

Vancouver:

Mroue AM. Energy Portfolio Assessment Tool (EPAT): Sustainable Energy Planning Using the WEF Nexus Approach - Texas Case Study. [Internet] [Masters thesis]. Texas A&M University; 2017. [cited 2021 Apr 10]. Available from: http://hdl.handle.net/1969.1/165861.

Council of Science Editors:

Mroue AM. Energy Portfolio Assessment Tool (EPAT): Sustainable Energy Planning Using the WEF Nexus Approach - Texas Case Study. [Masters Thesis]. Texas A&M University; 2017. Available from: http://hdl.handle.net/1969.1/165861

Texas A&M University

13. Wu, Haoran. Effect of Carbon Dioxide-Sustained Adsorption Using Ion Exchange Resin on Mixed-Acid Fermentation.

Degree: MS, Chemical Engineering, 2018, Texas A&M University

URL: http://hdl.handle.net/1969.1/174328

► The carboxylate platform is a biomass-to-energy process that converts biomass into hydrocarbon fuels or chemicals. The mixed-acid fermentation is the essential unit of the process… (more)

Subjects/Keywords: Biofuel; Carboxylate platform; Anaerobic digestion; Ion-exchange resin; in-situ separation

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APA (6^th Edition):

Wu, H. (2018). Effect of Carbon Dioxide-Sustained Adsorption Using Ion Exchange Resin on Mixed-Acid Fermentation. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/174328

Chicago Manual of Style (16^th Edition):

Wu, Haoran. “Effect of Carbon Dioxide-Sustained Adsorption Using Ion Exchange Resin on Mixed-Acid Fermentation.” 2018. Masters Thesis, Texas A&M University. Accessed April 10, 2021. http://hdl.handle.net/1969.1/174328.

MLA Handbook (7^th Edition):

Wu, Haoran. “Effect of Carbon Dioxide-Sustained Adsorption Using Ion Exchange Resin on Mixed-Acid Fermentation.” 2018. Web. 10 Apr 2021.

Vancouver:

Wu H. Effect of Carbon Dioxide-Sustained Adsorption Using Ion Exchange Resin on Mixed-Acid Fermentation. [Internet] [Masters thesis]. Texas A&M University; 2018. [cited 2021 Apr 10]. Available from: http://hdl.handle.net/1969.1/174328.

Council of Science Editors:

Wu H. Effect of Carbon Dioxide-Sustained Adsorption Using Ion Exchange Resin on Mixed-Acid Fermentation. [Masters Thesis]. Texas A&M University; 2018. Available from: http://hdl.handle.net/1969.1/174328

Texas A&M University

14. Hsu, Shen-Chun. Effects of Product Removal Using Ion-exchange Resin and Sodium Hydroxide Pretreatment in Mixed-culture Fermentation.

Degree: MS, Chemical Engineering, 2019, Texas A&M University

URL: http://hdl.handle.net/1969.1/187592

► In mixed-culture fermentations of lignocellulosic biomass, periodical product removal has proven to reduce product inhibition and thereby increase biomass digestion. Previously, ion-exchange resin (Amberlite IRA-67)… (more)

▼ In mixed-culture fermentations of lignocellulosic biomass, periodical product removal has proven to reduce product inhibition and thereby increase biomass digestion. Previously, ion-exchange resin (Amberlite IRA-67) was employed in countercurrent fermentation, and different amounts of resin loadings (10–40 g wet resin per 1.38 L total liquid volume) were studied. Using the pre-established culture (office paper and oven-dried chicken manure), this research used higher resin loadings (50, 60, and 80 g wet resin per 1.34 L total liquid volume). The 0.3-L resin column was sustained by COv2 (gas flow rate: 1.5 L/min). Compared to 30 g resin loading, when higher loadings were introduced, biomass conversion dropped by 0.05–0.09 g NAVSvdigested/g NAVSvfeed. Furthermore, the yield plateaued at resin loadings greater than 40 g. Overall, the optimal resin loading for both biomass conversion and acid yield was 30–40 resin loading per 1.34 L total liquid volume, which corresponded to 21.74–29.20 g wet resin/LvH2liq. As indicators of digestibility, cellulase (Ctec3) and hemicellulose (Htec3) were used to saccharify pretreated corn stover. Shock pretreatment subjects biomass to a high-pressure pulse to enhance enzyme accessibility to cellulose and hemicellulose. It was found that 5.52 bar (abs) initial Hv2/Ov2 filling pressure generated a sufficiently high shock pressure to produce good digestibility. Sodium hydroxide is a potent alkali for pretreatment. Shock treatment (5.52 bar (abs) filling pressure) followed by moderate temperature (50℃) with 4 g OH–/100 g dry biomass NaOH concentration for 1 h is the recommended treatment condition. The continuum particle distribution model (CPDM) simulates four-stage countercurrent mixed-culture fermentation from data obtained from batch experiments. Using the recommended pretreatment conditions described above, three different extents of pretreated corn stover were studied: (1) shock only, (2) NaOH only, and (3) shock + NaOH. As the nutrient source, sewage sludge was used together with raw or pretreated corn stover. Compared with raw corn stover, the CPDM map showed improvements in conversion and product concentration for NaOH treatment alone and shock + NaOH treatments; however, shock only made the corn stover less digestible. With shock + NaOH-treated corn stover, the model predicts the total carboxylic acid concentration of 36.1 g/L and conversion of 0.432 g NAVSvdigested/g NAVSvfeed at liquid retention time (LRT) of 35 day and volatile solid loading rate (VSLR) of 6 g/(L∙day). Advisors/Committee Members: Holtzapple, Mark T (advisor), Hilaly, Ahmad K (committee member), Nikolov, Zivko (committee member).

Subjects/Keywords: MixAlco process; Carboxylate Platform; countercurrent fermentation; ion-exchange resin; biomass; pretreatment; batch fermentation; corn stover; sewage sludge

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Hsu, S. (2019). Effects of Product Removal Using Ion-exchange Resin and Sodium Hydroxide Pretreatment in Mixed-culture Fermentation. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/187592

Chicago Manual of Style (16^th Edition):

Hsu, Shen-Chun. “Effects of Product Removal Using Ion-exchange Resin and Sodium Hydroxide Pretreatment in Mixed-culture Fermentation.” 2019. Masters Thesis, Texas A&M University. Accessed April 10, 2021. http://hdl.handle.net/1969.1/187592.

MLA Handbook (7^th Edition):

Hsu, Shen-Chun. “Effects of Product Removal Using Ion-exchange Resin and Sodium Hydroxide Pretreatment in Mixed-culture Fermentation.” 2019. Web. 10 Apr 2021.

Vancouver:

Hsu S. Effects of Product Removal Using Ion-exchange Resin and Sodium Hydroxide Pretreatment in Mixed-culture Fermentation. [Internet] [Masters thesis]. Texas A&M University; 2019. [cited 2021 Apr 10]. Available from: http://hdl.handle.net/1969.1/187592.

Council of Science Editors:

Hsu S. Effects of Product Removal Using Ion-exchange Resin and Sodium Hydroxide Pretreatment in Mixed-culture Fermentation. [Masters Thesis]. Texas A&M University; 2019. Available from: http://hdl.handle.net/1969.1/187592

Texas A&M University

15. Wang, Yang. An Investigation of Optimal Design of Hybrid Electric Vehicle with a Starrotor Engine.

Degree: PhD, Electrical Engineering, 2015, Texas A&M University

URL: http://hdl.handle.net/1969.1/174217

► Fuel economy of conventional hybrid electric vehicles (HEVs) gets limited improvements because of constraints from conventional internal combustion engines (ICEs). Electric vehicles (EVs) have the… (more)

Subjects/Keywords: Hybrid Electric Vehicle; Dynamic Programming; StarRotor engine; Optimal Design

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APA (6^th Edition):

Wang, Y. (2015). An Investigation of Optimal Design of Hybrid Electric Vehicle with a Starrotor Engine. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/174217

Chicago Manual of Style (16^th Edition):

Wang, Yang. “An Investigation of Optimal Design of Hybrid Electric Vehicle with a Starrotor Engine.” 2015. Doctoral Dissertation, Texas A&M University. Accessed April 10, 2021. http://hdl.handle.net/1969.1/174217.

MLA Handbook (7^th Edition):

Wang, Yang. “An Investigation of Optimal Design of Hybrid Electric Vehicle with a Starrotor Engine.” 2015. Web. 10 Apr 2021.

Vancouver:

Wang Y. An Investigation of Optimal Design of Hybrid Electric Vehicle with a Starrotor Engine. [Internet] [Doctoral dissertation]. Texas A&M University; 2015. [cited 2021 Apr 10]. Available from: http://hdl.handle.net/1969.1/174217.

Council of Science Editors:

Wang Y. An Investigation of Optimal Design of Hybrid Electric Vehicle with a Starrotor Engine. [Doctoral Dissertation]. Texas A&M University; 2015. Available from: http://hdl.handle.net/1969.1/174217

Texas A&M University

16. Teipel, Blake. Polymeric Composites with Cellulose Nanomaterials: Development of Synergistic Treatments and Stabilization Schema.

Degree: PhD, Materials Science and Engineering, 2016, Texas A&M University

URL: http://hdl.handle.net/1969.1/158111

► A combination of scientific and commercial research efforts are presented in this work. Exploits in both early- and late-stage research and subsequent scale-up opportunities are… (more)

▼ A combination of scientific and commercial research efforts are presented in this work. Exploits in both early- and late-stage research and subsequent scale-up opportunities are discussed, in particular, highlighting novel idea-to-market approaches suitable for composite materials with nanoscale fillers. Both polymeric and metallic nanocomposites are commercially explored, whereas answers to fundamental questions for polymeric composites filled with biologically derived nanomaterials are provided. In the first example, the role of a stabilizer in the stiffening and strengthening of cellulose nanocrystal (CNC) filled epoxy was studied. Cetyltrimethylammonium bromide (CTAB), a cationic surfactant, and Boehmite nanoclay (Boe) were mixed with CNCs in water during processing. Boe+CTAB synergistically stiffened the CNC-epoxy composites, increasing elastic modulus by 72% over neat epoxy and 49% over unstabilized CNC-epoxy composites. Boe-treated CNC-epoxy composites exhibited a 23% increase in tensile strength over unfilled epoxy and a 63% increase over an unstabilized CNC-epoxy composite. These nanocomposites also maintained the strain-at- failure of neat epoxy and increased the storage modulus above Tg by 96%. Then, in a second example, amine functionalization provided a functional layer between cellulose nanocrystals (CNCs) and polypropylene. Diethylenetriamine (DETA) was combined with polypropylene (PP) and then with CNCs in high-shear mixing. DETA-treatment stiffened the CNC-PP composites increasing elastic modulus by 75% over neat PP and untreated CNC-PP composites. DETA-treated CNC-PP composites also exhibited a 32% increase in tensile strength over unfilled PP and a 28% improvement for CNC-PP composites without DETA treatment. These nanocomposites were prepared without the use of organic solvents using a scalable, high-volume manufacturing approach. A commercial scale-up plan for this work is presented in detail. Thermal interface materials (TIMs) are required to enhance the contact between component surfaces, decrease thermal interfacial resistance, and increase heat conduction across the interface. A new TIM discussed herein is prepared using an already established technique of electrocodeposition, forming a flexible, nanocomposite film. The film is highly compliant, utilizing an ultra-high thermal conductivity greater than 250 W/m・K, as opposed to the best commercially available TIMs with conductivities ranging from 5–80 W/mK. This technology also achieves a total bulk thermal impedance of 1–4 × 10^-3 K・cm²/W, an order of magnitude lower than commercially available TIMs Advisors/Committee Members: Akbulut, Mustafa (advisor), Green, Micah (committee member), Creasy, Terry (committee member), Holtzapple, Mark (committee member).

Subjects/Keywords: Cellulose; Nanomaterials

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APA (6^th Edition):

Teipel, B. (2016). Polymeric Composites with Cellulose Nanomaterials: Development of Synergistic Treatments and Stabilization Schema. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/158111

Chicago Manual of Style (16^th Edition):

Teipel, Blake. “Polymeric Composites with Cellulose Nanomaterials: Development of Synergistic Treatments and Stabilization Schema.” 2016. Doctoral Dissertation, Texas A&M University. Accessed April 10, 2021. http://hdl.handle.net/1969.1/158111.

MLA Handbook (7^th Edition):

Teipel, Blake. “Polymeric Composites with Cellulose Nanomaterials: Development of Synergistic Treatments and Stabilization Schema.” 2016. Web. 10 Apr 2021.

Vancouver:

Teipel B. Polymeric Composites with Cellulose Nanomaterials: Development of Synergistic Treatments and Stabilization Schema. [Internet] [Doctoral dissertation]. Texas A&M University; 2016. [cited 2021 Apr 10]. Available from: http://hdl.handle.net/1969.1/158111.

Council of Science Editors:

Teipel B. Polymeric Composites with Cellulose Nanomaterials: Development of Synergistic Treatments and Stabilization Schema. [Doctoral Dissertation]. Texas A&M University; 2016. Available from: http://hdl.handle.net/1969.1/158111

Texas A&M University

17. Yang, Kefan. Effect of Liquid Residence Time, Extraction, and Chain Elongation on Countercurrent Mixed-Acid Fermentations.

Degree: MS, Chemical Engineering, 2017, Texas A&M University

URL: http://hdl.handle.net/1969.1/161630

► The carboxylate platform is one of three recognized processes (sugar, thermochemical, and carboxylate) that converts biomass into chemicals and hydrocarbon fuels. One example of the… (more)

▼ The carboxylate platform is one of three recognized processes (sugar, thermochemical, and carboxylate) that converts biomass into chemicals and hydrocarbon fuels. One example of the carboxylate platform is the MixAlco process. Using mixed-culture countercurrent fermentation, biomass is digested into carboxylate salts. Using chemical reactions (e.g., hydrogenation), a variety of products are produced such as alcohols, esters, ketones, and ethers. In this process, methane production is blocked using an inhibitor, which enhances product value. To enhance the conversion of biomass and increase product yields, the following experiments were done. To extend the liquid residence time, the liquid maintenance target was adjusted to increase the total liquid volume of the system. The average liquid residence time was 88.9 days compared with the traditional 20–30 days. The results show that the concentration of liquid product is 34.3 g/L, conversion is 64.2%, yield is 11.2%, acetic acid equivalent yield (aceq) is 16.6%, selectivity is 17.5%, and acetic acid equivalent selectivity is 25.9%. Also, this countercurrent system shown comparably high selectivity to butyric acid. Using the established steady-state countercurrent fermentation system described above, all the conditions are the same except for the usage of resin extraction. The average concentration of liquid product is 28.4 g/L which is lower because of the extraction. The conversion is 70.3%, total acid yield (including resin extraction) is 16.5%, aceq total acid yield is 27.0%, selectivity is 23.4%, and aceq selectivity is 38.5%. The conversion, yield, and selectivity all were enhanced. The extraction enhances the selectivity of liquid product, especially the selectivity of medium-chain carboxylic acids (C5–C7), which means extraction using a resin promotes chain elongation in the secondary fermentation. One explanation is that extraction reduces product inhibition. Introducing ethanol to a countercurrent fermentation system shows different phenomenon compared with a previously investigated batch system. In countercurrent fermentation, primary fermentation was promoted, but chain-elongation was inhibited. In contrast, batch fermentation enhanced chain-elongation. Advisors/Committee Members: Holtzapple, Mark T (advisor), Kao, Katy (committee member), Capareda, Sergio C (committee member).

Subjects/Keywords: Liquid Residence Time; Extraction; Resin; Chain Elongation; Countercurrent Fermentation

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APA (6^th Edition):

Yang, K. (2017). Effect of Liquid Residence Time, Extraction, and Chain Elongation on Countercurrent Mixed-Acid Fermentations. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/161630

Chicago Manual of Style (16^th Edition):

Yang, Kefan. “Effect of Liquid Residence Time, Extraction, and Chain Elongation on Countercurrent Mixed-Acid Fermentations.” 2017. Masters Thesis, Texas A&M University. Accessed April 10, 2021. http://hdl.handle.net/1969.1/161630.

MLA Handbook (7^th Edition):

Yang, Kefan. “Effect of Liquid Residence Time, Extraction, and Chain Elongation on Countercurrent Mixed-Acid Fermentations.” 2017. Web. 10 Apr 2021.

Vancouver:

Yang K. Effect of Liquid Residence Time, Extraction, and Chain Elongation on Countercurrent Mixed-Acid Fermentations. [Internet] [Masters thesis]. Texas A&M University; 2017. [cited 2021 Apr 10]. Available from: http://hdl.handle.net/1969.1/161630.

Council of Science Editors:

Yang K. Effect of Liquid Residence Time, Extraction, and Chain Elongation on Countercurrent Mixed-Acid Fermentations. [Masters Thesis]. Texas A&M University; 2017. Available from: http://hdl.handle.net/1969.1/161630

Texas A&M University

18. Zentay, Agustin Nicholas. Countercurrent Enzymatic Saccharification of Lignocellulosic Biomass and Improvements Over Batch Operation.

Degree: MS, Chemical Engineering, 2014, Texas A&M University

URL: http://hdl.handle.net/1969.1/152675

► Transportation fuels are the major driver for fossil fuel production, a burden that many countries have tried to ease by blending fossil fuels with biofuel… (more)

▼ Transportation fuels are the major driver for fossil fuel production, a burden that many countries have tried to ease by blending fossil fuels with biofuel substitutes such as ethanol. Current U.S. ethanol production relies on fermentation of starchy biomass (e.g., corn), which competes with food. Using lignocellulose avoids competition with food; however, it is difficult to digest using traditional batch saccharification. This work investigates countercurrent saccharification as an alternative that reduces enzyme requirements. Compared to baseline yields for standard batch saccharification, countercurrent saccharification reduces enzyme requirements by 5 to 37 times. Initial studies identified Solka-Floc as an acceptable substrate to represent treated biomass; it is readily available and reliably consistent from sample to sample. To measure yields, batch saccharifications were performed at various enzyme loadings and reaction times. Two relatively low enzyme concentrations were selected for further study: 2 and 5 mg protein/g biomass, or 2.6 and 6.4 mg protein/g glucan, respectively. Both of the selected loadings are below levels suggested for commercial use. For each enzyme loading tested, a multi-stage, semi-continuous countercurrent train was constructed. The first experiments used trains consisting of eight 1-L bottles loaded with α-cellulose, using the same concentrations as the batch experiments. Liquid and solid phases were countercurrently contacted, with transfers of each phase occurring every second day for approximately 4‒6 weeks, until steady-state operation was maintained for at least 10 days. At 2 and 5 mg/g enzyme loadings, total sugar yields reached 55.9% and 85.3%, respectively. A follow up study using 16 bottles and 2 mg/g loading produced total sugar yields of 73.4%. In the interest of future scale-up, alternatives to the cycloheximide and tetracycline antibiotic cocktail were investigated. Preliminary results suggest that chloroform or a volatile essential plant oil may be effective. Future work is needed to confirm the antimicrobial strength of these compounds at low concentrations, which is needed to limit enzyme inhibition. Advisors/Committee Members: Holtzapple, Mark T (advisor), Glover, Charles J (committee member), Capareda, Sergio (committee member).

Subjects/Keywords: countercurrent; enzymes; enzymatic; saccharification; sugar; biofuels; ethanol

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APA (6^th Edition):

Zentay, A. N. (2014). Countercurrent Enzymatic Saccharification of Lignocellulosic Biomass and Improvements Over Batch Operation. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/152675

Chicago Manual of Style (16^th Edition):

Zentay, Agustin Nicholas. “Countercurrent Enzymatic Saccharification of Lignocellulosic Biomass and Improvements Over Batch Operation.” 2014. Masters Thesis, Texas A&M University. Accessed April 10, 2021. http://hdl.handle.net/1969.1/152675.

MLA Handbook (7^th Edition):

Zentay, Agustin Nicholas. “Countercurrent Enzymatic Saccharification of Lignocellulosic Biomass and Improvements Over Batch Operation.” 2014. Web. 10 Apr 2021.

Vancouver:

Zentay AN. Countercurrent Enzymatic Saccharification of Lignocellulosic Biomass and Improvements Over Batch Operation. [Internet] [Masters thesis]. Texas A&M University; 2014. [cited 2021 Apr 10]. Available from: http://hdl.handle.net/1969.1/152675.

Council of Science Editors:

Zentay AN. Countercurrent Enzymatic Saccharification of Lignocellulosic Biomass and Improvements Over Batch Operation. [Masters Thesis]. Texas A&M University; 2014. Available from: http://hdl.handle.net/1969.1/152675

Texas A&M University

19. Cui, Yuanchen. Exploration of Pavement Oxidation Model Applications and Field Validation.

Degree: PhD, Chemical Engineering, 2014, Texas A&M University

URL: http://hdl.handle.net/1969.1/153666

► Asphalt paved road is one of the building blocks of the modem world. Flexibility is one of its major advantages; however, this flexibility suffers from… (more)

▼ Asphalt paved road is one of the building blocks of the modem world. Flexibility is one of its major advantages; however, this flexibility suffers from asphalt oxidation since the first day of pavement service life. Several elements of binder oxidation have been investigated, such as oxidation kinetics, asphalt hardening in response to oxidation, pavement design, and environmental conditions. Based on understandings on those elements, pavement oxidation models have been developed to predict the oxidation rates in pavements in specific locations. This prediction contributes greatly to reducing the pavement life cost and elongating pavement service life. However, experimental methods to determine required model inputs, values of those oxidation elements, seriously limit the model application. This work focuses on understanding the elements of asphalt oxidation and on exploring applications of the pavement oxidation model. This dissertation presents a detailed investigation of pavement oxidation, two new test methods to obtain the model inputs, and a study on dynamic diffusion-reaction balance. First, a detailed investigation on pavement oxidation was reported to give some general conclusions about asphalt oxidation rates vary largely in different climate zones, and pavement design defines thickness of the asphalt film and thus controls aging. Secondly, new methods to obtain the model inputs were proposed: (1) Aging tests on laboratory made asphalt concretes have been proven as new information sources on asphalt concretes aging to replace sampling field cores. This method makes a pavement oxidation prediction before construction a reality; (2) Aging on recovered asphalt binders have been proven as new information sources on asphalt kinetics and hardening properties. This method solves the problem that original binders are not available in many cases. With the data obtained from these aging tests, long term oxidation predictions for the pavements were made using the pavement oxidation model and validated their accuracies by field data, including one complicated case, a layer-by-layer prediction on a seal coat treated pavement. To better understand the asphalt aging process, the last topic in this dissertation was to study a dynamic balance between oxygen diffusion and oxidation reaction using the pavement oxidation model. Advisors/Committee Members: Glover, Charles (advisor), Martin, Amy Epps (committee member), Holtzapple, Mark (committee member), Wilhite, Benjamin (committee member).

Subjects/Keywords: Asphalt oxidation; pavement oxidation model

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APA (6^th Edition):

Cui, Y. (2014). Exploration of Pavement Oxidation Model Applications and Field Validation. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/153666

Chicago Manual of Style (16^th Edition):

Cui, Yuanchen. “Exploration of Pavement Oxidation Model Applications and Field Validation.” 2014. Doctoral Dissertation, Texas A&M University. Accessed April 10, 2021. http://hdl.handle.net/1969.1/153666.

MLA Handbook (7^th Edition):

Cui, Yuanchen. “Exploration of Pavement Oxidation Model Applications and Field Validation.” 2014. Web. 10 Apr 2021.

Vancouver:

Cui Y. Exploration of Pavement Oxidation Model Applications and Field Validation. [Internet] [Doctoral dissertation]. Texas A&M University; 2014. [cited 2021 Apr 10]. Available from: http://hdl.handle.net/1969.1/153666.

Council of Science Editors:

Cui Y. Exploration of Pavement Oxidation Model Applications and Field Validation. [Doctoral Dissertation]. Texas A&M University; 2014. Available from: http://hdl.handle.net/1969.1/153666

Texas A&M University

20. Liang, Chao. Batch Enzymatic Hydrolysis of Pretreated Corn Stover and Improvements with Countercurrent Saccharification.

Degree: MS, Chemical Engineering, 2015, Texas A&M University

URL: http://hdl.handle.net/1969.1/155692

► Enzymatic saccharification of non-food biomass, such as lignocellulose, can produce sugars. Sugars are the common feedstock for bioethanol, which can be substituted for transportation fuel… (more)

▼ Enzymatic saccharification of non-food biomass, such as lignocellulose, can produce sugars. Sugars are the common feedstock for bioethanol, which can be substituted for transportation fuel and address the shortage of fossil fuels. Traditional batch enzymatic saccharification usually wastes enzymes. An approach is countercurrent saccharification, which can make full use of enzymes and therefore reduce the enzyme loadings and lower the cost of sugar and biofuel production. In this research, various types of enzymes, enzyme loadings, and pretreatments for corn stover have been studied in batch hydrolysis to determine the preferred reaction conditions for countercurrent saccharification. Based on the results, cellulase CTec3 shows better enzymatic saccharification performance than CTec2 for both raw and pretreated corn stover. For a given enzyme dose, lime pretreatment improves enzymatic digestibility of corn stover significantly. Shock treatment of lime-treated corn stover further increases substrate digestibility. At a CTec3 dose of 10 mg protein/g dry biomass, the glucose yield of lime + shock treated corn stover is close to 100%. In contrast, lime pretreated corn stover yields 85%, and raw corn stover yields only 25%. For lime + shock treated corn stover, adding additional HTec3 (1 mg protein/g dry biomass) improved both glucose and xylose yields nearly 30% compared to CTec3 (1 mg protein/g dry biomass). The effect of production inhibition on enzyme activity was also tested. When 80 g/L glucose was initially added, glucose and xylose yields decrease 20% and 5%, respectively. Countercurrent saccharification of lime + shock treated corn stover with enzyme CTec3 (1 mg protein/g dry biomass) and CTec3 (1 mg protein/g dry biomass) + HTec3 (1 mg protein/g dry biomass) was studied. When the systems reached steady state, the Slope Method was used to determine product yields and verify that steady state was achieved. For CTec3 (1 mg protein/g dry biomass), the glucose and xylose yields were 64% and 39%, respectively. For CTec3 (1 mg protein/g dry biomass) + HTec3 (1 mg protein/g dry biomass), glucose and xylose yields were 72% and 62%, respectively. To reach a given glucose yield (64%), when only adding CTec3, countercurrent saccharification saves nearly 50% of the enzyme loading compared with batch saccharification. To reach a given glucose yield (72%), when adding CTec3 and HTec3 (50%:50%), countercurrent saccharification saves nearly 30% of the enzyme loading compared with batch saccharification. It requires approximately two months to achieve steady-state countercurrent saccharification. In the future, simulation work is necessary to determine the optimal operating condition. Continuum Particle Distribution Modeling (CPDM) is a potential model to simulate countercurrent saccharification. Advisors/Committee Members: Holtzapple, Mark T (advisor), Karim, M. Nazmul (advisor), Nikolov, Zivko (committee member).

Subjects/Keywords: Batch Saccharification; Countercurrent Saccharification

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APA (6^th Edition):

Liang, C. (2015). Batch Enzymatic Hydrolysis of Pretreated Corn Stover and Improvements with Countercurrent Saccharification. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/155692

Chicago Manual of Style (16^th Edition):

Liang, Chao. “Batch Enzymatic Hydrolysis of Pretreated Corn Stover and Improvements with Countercurrent Saccharification.” 2015. Masters Thesis, Texas A&M University. Accessed April 10, 2021. http://hdl.handle.net/1969.1/155692.

MLA Handbook (7^th Edition):

Liang, Chao. “Batch Enzymatic Hydrolysis of Pretreated Corn Stover and Improvements with Countercurrent Saccharification.” 2015. Web. 10 Apr 2021.

Vancouver:

Liang C. Batch Enzymatic Hydrolysis of Pretreated Corn Stover and Improvements with Countercurrent Saccharification. [Internet] [Masters thesis]. Texas A&M University; 2015. [cited 2021 Apr 10]. Available from: http://hdl.handle.net/1969.1/155692.

Council of Science Editors:

Liang C. Batch Enzymatic Hydrolysis of Pretreated Corn Stover and Improvements with Countercurrent Saccharification. [Masters Thesis]. Texas A&M University; 2015. Available from: http://hdl.handle.net/1969.1/155692

Texas A&M University

21. Weber, Jamie. Passive Flow Control Method for Mitigation of Unsteady Load Excursions on a Wind Turbine Blade.

Degree: MS, Aerospace Engineering, 2012, Texas A&M University

URL: http://hdl.handle.net/1969.1/156350

► Stochastic flow conditions, such as large unsteady wind gusts and coherent structures in turbulent winds, cause detrimental blade loadings to horizontal axis wind turbines (HAWT).… (more)

▼ Stochastic flow conditions, such as large unsteady wind gusts and coherent structures in turbulent winds, cause detrimental blade loadings to horizontal axis wind turbines (HAWT). Such loadings lead to large blade root bending moments, increased blade fatigue damage, and inconsistent rotor torque and thrust. In the present work, robust, fast-response passive flow control (PFC) methods for mitigating adverse effects from unsteady aerodynamic loadings on a HAWT blade due were developed. The PFC methods examined were that of a leading-edge slot and a novel combination of two passive flow control devices, namely a leading-edge slot and a passively oscillating surface located at the slot exit (slot-flap). Wind tunnel tests were conducted at a Reynolds number of 0.3 x 10⁶ and unsteady flow conditions were produced by an upstream disturbance generator. The disturbance generator utilized shed vortices from a rapidly deflecting upstream airfoil to simulate high-frequency, impulse-like load excursions on the main airfoil, representative of large wind gusts and coherent structures in turbulent winds. Results from the test series demonstrated reduced maximum load excursions of 7 to 9% using the PFC methods as compared to clean airfoil tests. Effectiveness of the PFC methods decreased for loading with multiple vortex interactions. To further examine the influence of the slot-flap oscillations, two additional slot-flap configurations were examined: (1) increased rigidity and thickness and (2) reduced length. Both variations indicated a further reduction of transient load excursions from 8 to 12% as compared to a clean airfoil. Coefficient of momentum (c_mu) was calculated for each slot-flap configuration, which was on the order of 1% and varied with angle of attack. The reduced excitation frequency (F+) ranged from 0.96 to 1.23 based upon the slot-flap configuration. The three slot-flap variations showed comparable c_mu and F+ average values and were within the uncertainty limits, indicating that the improved mitigation from the slot-flap variations is not attributed to c_mu and F+ contributions. Based upon this study, the location and oscillation amplitude of the slot-flap configurations are significant parameters in the resulting mitigation effects. Advisors/Committee Members: Rediniotis, Othon K (advisor), White, Edward B (committee member), Holtzapple, Mark T (committee member).

Subjects/Keywords: unsteady aerodynamics; flow control; wind turbine blade

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APA (6^th Edition):

Weber, J. (2012). Passive Flow Control Method for Mitigation of Unsteady Load Excursions on a Wind Turbine Blade. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/156350

Chicago Manual of Style (16^th Edition):

Weber, Jamie. “Passive Flow Control Method for Mitigation of Unsteady Load Excursions on a Wind Turbine Blade.” 2012. Masters Thesis, Texas A&M University. Accessed April 10, 2021. http://hdl.handle.net/1969.1/156350.

MLA Handbook (7^th Edition):

Weber, Jamie. “Passive Flow Control Method for Mitigation of Unsteady Load Excursions on a Wind Turbine Blade.” 2012. Web. 10 Apr 2021.

Vancouver:

Weber J. Passive Flow Control Method for Mitigation of Unsteady Load Excursions on a Wind Turbine Blade. [Internet] [Masters thesis]. Texas A&M University; 2012. [cited 2021 Apr 10]. Available from: http://hdl.handle.net/1969.1/156350.

Council of Science Editors:

Weber J. Passive Flow Control Method for Mitigation of Unsteady Load Excursions on a Wind Turbine Blade. [Masters Thesis]. Texas A&M University; 2012. Available from: http://hdl.handle.net/1969.1/156350

Texas A&M University

22. Zou, Amy Fangze. Compositional Simulation of CO2 Enhanced Oil Recovery in Unconventional Liquid Reservoirs.

Degree: MS, Petroleum Engineering, 2015, Texas A&M University

URL: http://hdl.handle.net/1969.1/156374

► After implications of hydraulic fracturing operations, the commercial production of tight formations and shale plays were successfully achieved in past decades. The industry now shifts… (more)

Subjects/Keywords: CO2; gas injection; unconventional reservoirs; compositional simulation; diffusion

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APA (6^th Edition):

Zou, A. F. (2015). Compositional Simulation of CO2 Enhanced Oil Recovery in Unconventional Liquid Reservoirs. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/156374

Chicago Manual of Style (16^th Edition):

Zou, Amy Fangze. “Compositional Simulation of CO2 Enhanced Oil Recovery in Unconventional Liquid Reservoirs.” 2015. Masters Thesis, Texas A&M University. Accessed April 10, 2021. http://hdl.handle.net/1969.1/156374.

MLA Handbook (7^th Edition):

Zou, Amy Fangze. “Compositional Simulation of CO2 Enhanced Oil Recovery in Unconventional Liquid Reservoirs.” 2015. Web. 10 Apr 2021.

Vancouver:

Zou AF. Compositional Simulation of CO2 Enhanced Oil Recovery in Unconventional Liquid Reservoirs. [Internet] [Masters thesis]. Texas A&M University; 2015. [cited 2021 Apr 10]. Available from: http://hdl.handle.net/1969.1/156374.

Council of Science Editors:

Zou AF. Compositional Simulation of CO2 Enhanced Oil Recovery in Unconventional Liquid Reservoirs. [Masters Thesis]. Texas A&M University; 2015. Available from: http://hdl.handle.net/1969.1/156374

Texas A&M University

23. Li, Jue. ASSESSING POTENTIAL DIFFERENCES OF DIESEL FUEL EFFECTS ON COMBUSTION AND ENGINE BEHAVIOR BETWEEN DIFFERENTLY-SIZED ENGINES.

Degree: PhD, Mechanical Engineering, 2017, Texas A&M University

URL: http://hdl.handle.net/1969.1/187286

► Fuel properties impact the combustion and emissions behavior of diesel engines through their influence on the physical process associated with fuel injection, entrainment and fuel-air… (more)

▼ Fuel properties impact the combustion and emissions behavior of diesel engines through their influence on the physical process associated with fuel injection, entrainment and fuel-air mixing, as well as by changes to the combustion chemistry associated with fuel properties. In addition, these influences are also impacted strongly by various engine sizes. Thus, to find fuel effects on engine behavior between two engines, the research is conducted through a series of experimental tests at 1500 rev/min and two loads for commercial diesel and Fuels for Advanced Combustion Engines fuels between two engines. First, baseline testing and simulation was aimed at using experiment and a simulation model of two differently sized engines to identify the effects of engine size on combustion characteristics and emissions. The results are compared for the same brake mean effective pressure and show that engine size has a significant impact on indicated efficiency, with the larger displaced engine having a higher indicated efficiency than the smaller displaced engine. Second, the effects of cetane number (CN) on combustion and emissions between differently sized engines were investigated using a fuel matrix with each variable having a base value as well as a lower and higher level. The results show that CN significantly affects combustion phasing and emissions of the two engines in similar ways. As CN increases, the magnitude of heat release rate (HRR) increases and its peak location advances as CN increases. Moreover, the effects of distillation temperature (T90) on engine efficiency and emissions are performed. The results show comparing with medium-duty (MD) engine performance, increasing T90 shows relative stronger effects on HRR for light-duty (LD) engine, especially for the low-load condition. Finally, the effects of aromatic content on engine efficiency and emissions are discussed. The results show increasing aromatic content increases the magnitude of the peak HRR, and delays its location for both engines at the low-load condition. At the medium-load condition, increasing aromatic content has similar effect on LD engine, but does not show obvious effect on MD engines. Advisors/Committee Members: Jacobs, Timothy (advisor), Caton, Jerald (committee member), Annamalai, Kalyan (committee member), Holtzapple, Mark (committee member).

Subjects/Keywords: Combustion; emissions; engine size; fuel property

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APA (6^th Edition):

Li, J. (2017). ASSESSING POTENTIAL DIFFERENCES OF DIESEL FUEL EFFECTS ON COMBUSTION AND ENGINE BEHAVIOR BETWEEN DIFFERENTLY-SIZED ENGINES. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/187286

Chicago Manual of Style (16^th Edition):

Li, Jue. “ASSESSING POTENTIAL DIFFERENCES OF DIESEL FUEL EFFECTS ON COMBUSTION AND ENGINE BEHAVIOR BETWEEN DIFFERENTLY-SIZED ENGINES.” 2017. Doctoral Dissertation, Texas A&M University. Accessed April 10, 2021. http://hdl.handle.net/1969.1/187286.

MLA Handbook (7^th Edition):

Li, Jue. “ASSESSING POTENTIAL DIFFERENCES OF DIESEL FUEL EFFECTS ON COMBUSTION AND ENGINE BEHAVIOR BETWEEN DIFFERENTLY-SIZED ENGINES.” 2017. Web. 10 Apr 2021.

Vancouver:

Li J. ASSESSING POTENTIAL DIFFERENCES OF DIESEL FUEL EFFECTS ON COMBUSTION AND ENGINE BEHAVIOR BETWEEN DIFFERENTLY-SIZED ENGINES. [Internet] [Doctoral dissertation]. Texas A&M University; 2017. [cited 2021 Apr 10]. Available from: http://hdl.handle.net/1969.1/187286.

Council of Science Editors:

Li J. ASSESSING POTENTIAL DIFFERENCES OF DIESEL FUEL EFFECTS ON COMBUSTION AND ENGINE BEHAVIOR BETWEEN DIFFERENTLY-SIZED ENGINES. [Doctoral Dissertation]. Texas A&M University; 2017. Available from: http://hdl.handle.net/1969.1/187286

Texas A&M University

24. Bond, Austin Eli. Making Bombs for Peaceful Purposes: How Explosive Processes Render Lignocellulosic Biomass More Amenable to Biological Digestion.

Degree: PhD, Mechanical Engineering, 2016, Texas A&M University

URL: http://hdl.handle.net/1969.1/187373

► Experiments were performed to investigate the effects of shock waves – generated by explosive processes – on enhancing enzymatic digestibility of corn stover for conversion… (more)

▼ Experiments were performed to investigate the effects of shock waves – generated by explosive processes – on enhancing enzymatic digestibility of corn stover for conversion into biofuels, chemicals, or animal feed. Following an alkaline chemical pretreatment process, shock treatment was performed, which increased digestibility. Digestibility was assessed at a standard enzyme loading of 46.7 mg protein/g glucan. Without shock, the enzymatic conversion was 0.80 g glucan digested/g glucan fed. With shock, the enzyme loading is reduced by ~2× while maintaining a constant conversion. Shotgun shells and hydrogen detonation produced identical digestibility increases; however, hydrogen detonation eliminated the need to magnetically remove contaminants introduced from shotgun shells. Contrary to initial hypotheses, varying vessel geometry (depth = 1–3 ft, diameter = 4–8 in) or process conditions (peak pressure = 2.07–12.1 MPa, and solids concentration = 5–10%) had an insignificant impact on shock treatment efficacy within the experimental domain tested. Instead, the pressurization rate is the key parameter when scaling the shock treatment process. Specifically, the shotgun shell blast (108,000 MPa/s) and hydrogen detonation (4,160,000 MPa/s) generate pressure quickly enough to enhance digestibility; in contrast, the propane deflagration (37.2 MPa/s) did not. Therefore, process scaling is extremely simple, because a vessel that contains gas detonations should suffice. A slurry pump enables rapid cycling of the 20-L shock tube to already function at a commercially relevant scale. The maximum benefit of shock treatment has yet to be determined. Subsequent experiments performed with plasma discharge and solid explosives failed to increase digestibility, at the conditions employed; but, liquid-phase shock waves may be more effective. Advisors/Committee Members: Petersen, Eric (advisor), Holtzapple, Mark (advisor), Sue, Hung Jue (committee member), Staack, David (committee member).

Subjects/Keywords: Deflagration; Detonation; Shock Wave; Enzymatic Digestibility; Alkaline Pretreatment; Piezoelectronic; Data Acquisition

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APA (6^th Edition):

Bond, A. E. (2016). Making Bombs for Peaceful Purposes: How Explosive Processes Render Lignocellulosic Biomass More Amenable to Biological Digestion. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/187373

Chicago Manual of Style (16^th Edition):

Bond, Austin Eli. “Making Bombs for Peaceful Purposes: How Explosive Processes Render Lignocellulosic Biomass More Amenable to Biological Digestion.” 2016. Doctoral Dissertation, Texas A&M University. Accessed April 10, 2021. http://hdl.handle.net/1969.1/187373.

MLA Handbook (7^th Edition):

Bond, Austin Eli. “Making Bombs for Peaceful Purposes: How Explosive Processes Render Lignocellulosic Biomass More Amenable to Biological Digestion.” 2016. Web. 10 Apr 2021.

Vancouver:

Bond AE. Making Bombs for Peaceful Purposes: How Explosive Processes Render Lignocellulosic Biomass More Amenable to Biological Digestion. [Internet] [Doctoral dissertation]. Texas A&M University; 2016. [cited 2021 Apr 10]. Available from: http://hdl.handle.net/1969.1/187373.

Council of Science Editors:

Bond AE. Making Bombs for Peaceful Purposes: How Explosive Processes Render Lignocellulosic Biomass More Amenable to Biological Digestion. [Doctoral Dissertation]. Texas A&M University; 2016. Available from: http://hdl.handle.net/1969.1/187373

Texas A&M University

25. Liang, Chao. PROCESS DEVELOPMENT, KINETIC MODELING, AND TECHNO-ECONOMIC ANALYSIS OF ENZYMATIC CELLULOSE HYDROLYSIS.

Degree: PhD, Chemical Engineering, 2019, Texas A&M University

URL: http://hdl.handle.net/1969.1/188762

► Countercurrent saccharification is a promising way to minimize enzyme loading while obtaining high conversions and product concentrations. However, in countercurrent saccharification experiments, 3–4 months are… (more)

▼ Countercurrent saccharification is a promising way to minimize enzyme loading while obtaining high conversions and product concentrations. However, in countercurrent saccharification experiments, 3–4 months are usually required to acquire a single steady-state data point. To save labor and time, simulation of this process is necessary to test various reaction conditions and determine the optimal operating point. Previously, a suitable kinetic model for countercurrent saccharification has never been reported. To simulate countercurrent saccharification, a kinetic model that could satisfactorily predict batch saccharification under various reaction conditions is necessary. In this study, the HCH-1 model was modified to extend its application to integrated enzymatic hydrolysis; it performed well when predicting 10-day cellulose hydrolysis at various experimental conditions. Comparison with the literature models showed that the modified HCH-1 model provided the best fit for batch enzymatic cellulose hydrolysis. The Continuum Particle Distribution Modeling (CPDM) was applied to simulate countercurrent saccharification of α-cellulose. The modified HCH-1 model was used as the governing equation in the CPDM model. When validated against experimental countercurrent saccharification data, it predicts experimental glucose concentrations and conversions with the average errors of 3.5% and 4.7%, respectively. CPDM predicts conversion and product concentration with varying enzyme-addition location, total stage number, enzyme loading, liquid residence time, and solids loading rate. In addition, countercurrent saccharification was compared to batch saccharification at the same conversion, product concentration, and reactor volume. Results show that countercurrent saccharification is particularly beneficial when the product concentration is low. Techno-economic analysis was performed for cellulosic sugar production. Various reaction conditions, equipment materials, enzyme unit prices, and return on investments (ROIs) were considered. Excluding feedstock cost but including utility cost (dewatering), enzyme cost, depreciation, and fixed operating costs, using geomembrane reactor and carbon steel mechanical vapor recompression (MVR) evaporators, the estimated minimum selling prices are 0.079/kg glucose with commercial CTec2 cellulase (6.27/kg protein) and 0.064/kg glucose with on-site cellulase production (4.24/kg protein). Compared to batch saccharification at the same reaction conditions, equipment materials, and enzyme unit prices, countercurrent saccharification significantly reduces the cost of cellulosic sugar production. Advisors/Committee Members: Holtzapple, Mark (advisor), El-Halwagi, Mahmoud (committee member), Hilaly, Ahmad (committee member), Capareda, Sergio (committee member).

Subjects/Keywords: Process Development; Kinetic Modeling; Techno-economic Analysis; Enzymatic Cellulose Hydrolysis

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APA (6^th Edition):

Liang, C. (2019). PROCESS DEVELOPMENT, KINETIC MODELING, AND TECHNO-ECONOMIC ANALYSIS OF ENZYMATIC CELLULOSE HYDROLYSIS. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/188762

Chicago Manual of Style (16^th Edition):

Liang, Chao. “PROCESS DEVELOPMENT, KINETIC MODELING, AND TECHNO-ECONOMIC ANALYSIS OF ENZYMATIC CELLULOSE HYDROLYSIS.” 2019. Doctoral Dissertation, Texas A&M University. Accessed April 10, 2021. http://hdl.handle.net/1969.1/188762.

MLA Handbook (7^th Edition):

Liang, Chao. “PROCESS DEVELOPMENT, KINETIC MODELING, AND TECHNO-ECONOMIC ANALYSIS OF ENZYMATIC CELLULOSE HYDROLYSIS.” 2019. Web. 10 Apr 2021.

Vancouver:

Liang C. PROCESS DEVELOPMENT, KINETIC MODELING, AND TECHNO-ECONOMIC ANALYSIS OF ENZYMATIC CELLULOSE HYDROLYSIS. [Internet] [Doctoral dissertation]. Texas A&M University; 2019. [cited 2021 Apr 10]. Available from: http://hdl.handle.net/1969.1/188762.

Council of Science Editors:

Liang C. PROCESS DEVELOPMENT, KINETIC MODELING, AND TECHNO-ECONOMIC ANALYSIS OF ENZYMATIC CELLULOSE HYDROLYSIS. [Doctoral Dissertation]. Texas A&M University; 2019. Available from: http://hdl.handle.net/1969.1/188762

Texas A&M University

26. Liu, Kejia. Effects of Nutrients on Mixed-Culture Fermentation.

Degree: MS, Chemical Engineering, 2020, Texas A&M University

URL: http://hdl.handle.net/1969.1/191748

► The MixAlco® process, an example of the carboxylate platform, converts lignocellulosic biomass to hydrocarbon fuels and chemicals using mixing cultures. The performance of mixed-culture fermentation… (more)

▼ The MixAlco® process, an example of the carboxylate platform, converts lignocellulosic biomass to hydrocarbon fuels and chemicals using mixing cultures. The performance of mixed-culture fermentation depends on various factors, such as the energy source, nutrient source, and the resulting C/N ratio. It has been proven that co-digestion of two or more substrates has higher acid yields than either substrate fermented on its own. Countercurrent fermentation is employed to increase reaction rates and enhance acid yields and substrate conversion. However, it is time-consuming and labor intensive; it takes months to reach a single steady-state data point for a given liquid retention time (LRT) and volatile solids loading rates (VSLR). To overcome this challenge, the Continuum Particle Distribution Model (CPDM) is a technique that predicts the performance of countercurrent fermentation through mathematical methods using data from batch fermentations conducted at different substrate loadings. Effects of nutrients were studied using chicken manure (fresh, air-dried, and oven-dried) or sewage sludge (fresh and air-dried) as nutrient sources. Among all chicken manures, the CPDM map showed reduced conversion and acid concentration for oven-dried treatments, which suggests that the drying process damages the nutrient source. At high VSLR, air-dried nutrients have higher acid concentrations than fresh; however, the conversion is low, which adversely affects process economics. In mixed-culture fermentation, fresh nutrients are preferred. At the same conditions, fresh chicken manure and sewage sludge have similar acid concentration; however, in fermentations using sewage sludge, there is a larger portion of caproic acid. At 300 g solids/L liquid, the CPDM map predicts that high acid concentrations (48.2 g/L) and conversions (0.79 g NAVSdigested/g NAVSfeed) are obtained at low VSLR (4 g/(L·day)) and high LRT (35 days). Advisors/Committee Members: Holtzapple, Mark T (advisor), Hilaly, Ahmad K (committee member), Nikolov, Zivko (committee member).

Subjects/Keywords: MixAlco process; Carboxylate platform; fermentation; nutrients

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APA (6^th Edition):

Liu, K. (2020). Effects of Nutrients on Mixed-Culture Fermentation. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/191748

Chicago Manual of Style (16^th Edition):

Liu, Kejia. “Effects of Nutrients on Mixed-Culture Fermentation.” 2020. Masters Thesis, Texas A&M University. Accessed April 10, 2021. http://hdl.handle.net/1969.1/191748.

MLA Handbook (7^th Edition):

Liu, Kejia. “Effects of Nutrients on Mixed-Culture Fermentation.” 2020. Web. 10 Apr 2021.

Vancouver:

Liu K. Effects of Nutrients on Mixed-Culture Fermentation. [Internet] [Masters thesis]. Texas A&M University; 2020. [cited 2021 Apr 10]. Available from: http://hdl.handle.net/1969.1/191748.

Council of Science Editors:

Liu K. Effects of Nutrients on Mixed-Culture Fermentation. [Masters Thesis]. Texas A&M University; 2020. Available from: http://hdl.handle.net/1969.1/191748

Texas A&M University

27. Lonkar, Sagar Kishor. Maximizing Medium-chain Carboxylates in Mixed-culture Fermentation.

Degree: PhD, Chemical Engineering, 2016, Texas A&M University

URL: http://hdl.handle.net/1969.1/174276

► Global warming, steadily increasing energy demand, and limited fossil fuel reserves are growing concerns of modern society. In the past few decades, significant advances in… (more)

▼ Global warming, steadily increasing energy demand, and limited fossil fuel reserves are growing concerns of modern society. In the past few decades, significant advances in renewable energy research have helped reduce dependence on conventional non-renewable energy sources. Biofuels are sustainable and can replace petroleum-based fuels. Biofuels can be produced through three different platforms: thermochemical, sugar, and carboxylate. Based on experimental results, this dissertation suggests process improvements in the carboxylate and sugar platform to make biofuels more economically attractive. The carboxylate platform is a robust and scalable technology that produces fuels and chemicals from biomass. It employs methane-inhibited anaerobic fermentation to produce mainly short-chain fatty acids (SCFA, e.g., acetic, propanoic, butanoic, pentanoic). Medium-chain fatty acids (MCFA, e.g., hexanoic, heptanoic, octanoic acid) are more valuable than SCFAs. By feeding ethanol to the fermentor, MCFA formation is enhanced through chain elongation. To maximize MCFA production, alcohol concentrations and temperature were optimized in the mixed-culture fermentation. Chain elongation occurs at low temperatures (≤40 ⁰C) and does not occur at 55 ⁰C. Using the sugar platform, enzymes are a major cost contributor in biofuel production. Conventionally, enzymatic saccharification is performed in batch. To more efficiently use enzymes, a new continuous countercurrent method is explored. Pseudo-continuous countercurrent saccharification was performed on lime-pretreated corn stover at enzyme loadings of 1 mg CTec3/g dry biomass and (1 mg CTec3 + 1 mg HTec3)/g dry biomass and the results were compared with batch. To achieve the same glucan conversion as compared to batch, countercurrent saccharification reduced enzyme loading by 1.6 and 1.4 times at 1 mg protein/g biomass and 2 mg protein/g biomass, respectively. In rapidly growing developing countries, waste disposal is a major challenge. To address this challenge, the MixAlco process was investigated as an alternative to create economic incentives for waste disposal. The MixAlco process is one example of carboxylate platform. This work focuses on fermenting municipal solid waste in batch fermentations. Using the Continuum Particle Distribution Model (CPDM), the performance of continuous countercurrent fermentation was predicted at different volatile solid loading rates (VSLR) and liquid residence times (LRT). Advisors/Committee Members: Holtzapple, Mark T (advisor), El-Halwagi, Mahmoud (committee member), Glover, Charles (committee member), Karthikeyan, Raghupathy (committee member).

Subjects/Keywords: Mixed-culture fermentation; Chain elongation

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APA (6^th Edition):

Lonkar, S. K. (2016). Maximizing Medium-chain Carboxylates in Mixed-culture Fermentation. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/174276

Chicago Manual of Style (16^th Edition):

Lonkar, Sagar Kishor. “Maximizing Medium-chain Carboxylates in Mixed-culture Fermentation.” 2016. Doctoral Dissertation, Texas A&M University. Accessed April 10, 2021. http://hdl.handle.net/1969.1/174276.

MLA Handbook (7^th Edition):

Lonkar, Sagar Kishor. “Maximizing Medium-chain Carboxylates in Mixed-culture Fermentation.” 2016. Web. 10 Apr 2021.

Vancouver:

Lonkar SK. Maximizing Medium-chain Carboxylates in Mixed-culture Fermentation. [Internet] [Doctoral dissertation]. Texas A&M University; 2016. [cited 2021 Apr 10]. Available from: http://hdl.handle.net/1969.1/174276.

Council of Science Editors:

Lonkar SK. Maximizing Medium-chain Carboxylates in Mixed-culture Fermentation. [Doctoral Dissertation]. Texas A&M University; 2016. Available from: http://hdl.handle.net/1969.1/174276

Texas A&M University

28. Forrest, Andrea Kelly. Effects of Feedstocks and Inoculum Sources on Mixed-Acid and Hydrogen Fermentations.

Degree: PhD, Chemical Engineering, 2011, Texas A&M University

URL: http://hdl.handle.net/1969.1/ETD-TAMU-2010-12-8817

► With increasing energy demand, decreasing oil supply, and continuously accumulating waste in landfills, the interest in converting lignocellulosic biomass to liquid fuels has grown. The… (more)

▼ With increasing energy demand, decreasing oil supply, and continuously accumulating waste in landfills, the interest in converting lignocellulosic biomass to liquid fuels has grown. The MixAlco™ process requires no exogenous enzymes, no sterility, can be adapted to any biodegradable feedstock, and converts lignocellulosic biomass into valuable chemicals and transportation fuels. This work focuses on the effects different feedstocks and inocula have on mixed-acid/hydrogen fermentations. When volatile solids (VS) are digested, mixed-acid fermentations produce hydrogen gas as a secondary byproduct. Hydrogen is only produced when there is an excess of NADH within the cell and when the energy selectivity (gamma) of the system has not been met. Continuous fermentations of paper produced 16.7 g carboxylic acid/L and 15.7 mL H2/g VS digested. Continuous fermentations of pretreated bagasse produced 17.1 g carboxylic acid/L and 41.1 mL H2/g VS digested. Both fermentations produced a fraction of the theoretical amount of hydrogen. The paper fermentation had a hydrogen percent yield of 6.9 percent, whereas the bagasse fermentation had a hydrogen percent yield of 22.6 percent. Hydrogen production was capped at this level because gamma had been met for these systems. The Bioscreening Project, a joint project between three departments, sought to improve the MixAlco™ process by finding natural cultures containing high biomass converters and high acid producers. A total of 505 inoculum samples were collected from 19 sites and screened using paper and yeast extract fermentations. The best converters were analyzed with Continuum Particle Distribution Modeling (CPDM). Nine inocula were run in paper and yeast extract countercurrent fermentations in which the overall performance varied less than 13 percent. Comparisons between six countercurrent train cultures showed an average culture similarity of 0.40 (Yue-Clayton similarity). With the dissimilar microbial cultures and the very similar fermentation performance, the performance of the MixAlco™ process depends on fermentation conditions, not on the microorganisms. Batch fermentations of office paper wastes, pineapple residue, Aloe vera rinds, wood molasses, sugar molasses, extracted algae, non-extracted algae, crude glycerol, obtained from the biodiesel process, and pretreated water hyacinths produced sufficient carboxylic acids and had sufficiently high conversions to be viable substrates for the MixAlco™ process. Advisors/Committee Members: Holtzapple, Mark T. (advisor), Glover, Charles J. (committee member), Engler, Cady R. (committee member), El-Halwagi, Mahmoud (committee member).

Subjects/Keywords: MixAlco process; Mixed-Acid Fermentations; Hydrogen Fermentations

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Forrest, A. K. (2011). Effects of Feedstocks and Inoculum Sources on Mixed-Acid and Hydrogen Fermentations. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2010-12-8817

Chicago Manual of Style (16^th Edition):

Forrest, Andrea Kelly. “Effects of Feedstocks and Inoculum Sources on Mixed-Acid and Hydrogen Fermentations.” 2011. Doctoral Dissertation, Texas A&M University. Accessed April 10, 2021. http://hdl.handle.net/1969.1/ETD-TAMU-2010-12-8817.

MLA Handbook (7^th Edition):

Forrest, Andrea Kelly. “Effects of Feedstocks and Inoculum Sources on Mixed-Acid and Hydrogen Fermentations.” 2011. Web. 10 Apr 2021.

Vancouver:

Forrest AK. Effects of Feedstocks and Inoculum Sources on Mixed-Acid and Hydrogen Fermentations. [Internet] [Doctoral dissertation]. Texas A&M University; 2011. [cited 2021 Apr 10]. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2010-12-8817.

Council of Science Editors:

Forrest AK. Effects of Feedstocks and Inoculum Sources on Mixed-Acid and Hydrogen Fermentations. [Doctoral Dissertation]. Texas A&M University; 2011. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2010-12-8817

Texas A&M University

29. Hasaneen, Rasha F. Using Process and Lifecycle Analysis to Deliver Economically Effective Environmental Health, Safety and Sustainability Public Policy.

Degree: PhD, Interdisciplinary Engineering, 2016, Texas A&M University

URL: http://hdl.handle.net/1969.1/158942

► The intense focus on the intersection of energy and the environment has led to extensive discussion of both environmental issues and energy practices. While the… (more)

▼ The intense focus on the intersection of energy and the environment has led to extensive discussion of both environmental issues and energy practices. While the environmental health and safety (EHS) issues in oil and gas is a topic of concern for the industry, policy makers, and citizens, it is typically overshadowed by the economic viability of oil and gas operations. Many policy makers believe that EHS practices represent an increase in cost on capital businesses. As a result, they develop environmental policy using methods which force businesses to choose between costs and the environment. This research proposes a systematic approach to process analyses, based on the lean – six sigma discipline. It analyzes the economic and environmental footprints of existing oil and gas operations using a series of case studies and recommends environmentally favorable solutions. It then evaluates the impacts of these substitutions on both costs and EHS, combining economically and environmentally favorable solutions for oil and gas operations. The results are used to recommend environmental policy that should encourage adoption of the proposed solutions. Two types of processes were analyzed, a carbon capture and sequestration (CCS) operation associated with liquefied natural gas production, and shale gas production. In analyzing these operations, both environmentally and economically favorable solutions were reached. In addition, by looking at the microeconomic footprints of the operations, public policy recommendations were suggested to more effectively drive adoption of environmentally favorable technologies. In the case of CCS, the net present value (NPV) for operators with the 23/ton CO2 proposed carbon price is about 700,000,000. In the case of shale operations, environmental remediation options resulted in an NPV of 20,000,000 to 30,000,000, and a reduction of 20,000 to 40,000 tons of CO2 for a single well cluster. The lean‐six sigma approach has demonstrated the ability to develop both economically and environmentally favorable solutions. With this understanding of the economics of oil and gas operations, more effective public policy can be recommended. This approach can be used across industries in a similar manner to drive effective global environmental policy and encourage environmental technology adoption. Advisors/Committee Members: El-Halwagi, Mahmoud (advisor), Holtzapple, Mark (committee member), Mannan, M. Sam (committee member), Nasr-El-Din, Hisham (committee member).

Subjects/Keywords: environmental policy; carbon sequestration; shale gas; carbon dioxide fracturing; microeconomics; lean; six sigma; process analysis

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Hasaneen, R. F. (2016). Using Process and Lifecycle Analysis to Deliver Economically Effective Environmental Health, Safety and Sustainability Public Policy. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/158942

Chicago Manual of Style (16^th Edition):

Hasaneen, Rasha F. “Using Process and Lifecycle Analysis to Deliver Economically Effective Environmental Health, Safety and Sustainability Public Policy.” 2016. Doctoral Dissertation, Texas A&M University. Accessed April 10, 2021. http://hdl.handle.net/1969.1/158942.

MLA Handbook (7^th Edition):

Hasaneen, Rasha F. “Using Process and Lifecycle Analysis to Deliver Economically Effective Environmental Health, Safety and Sustainability Public Policy.” 2016. Web. 10 Apr 2021.

Vancouver:

Hasaneen RF. Using Process and Lifecycle Analysis to Deliver Economically Effective Environmental Health, Safety and Sustainability Public Policy. [Internet] [Doctoral dissertation]. Texas A&M University; 2016. [cited 2021 Apr 10]. Available from: http://hdl.handle.net/1969.1/158942.

Council of Science Editors:

Hasaneen RF. Using Process and Lifecycle Analysis to Deliver Economically Effective Environmental Health, Safety and Sustainability Public Policy. [Doctoral Dissertation]. Texas A&M University; 2016. Available from: http://hdl.handle.net/1969.1/158942

Texas A&M University

30. Palit, Chandra Mouli. Novel Pincer Complexes of Transition Metals for Reduction of Carbon Dioxide to Carbon Monoxide and Cross Coupling of Aryl Halides.

Degree: PhD, Chemistry, 2016, Texas A&M University

URL: http://hdl.handle.net/1969.1/158095

► Carbon dioxide is a major anthropogenic greenhouse gas and one of the biggest causes of global climate change. Utilization of CO2 to produce chemicals is… (more)

▼ Carbon dioxide is a major anthropogenic greenhouse gas and one of the biggest causes of global climate change. Utilization of CO2 to produce chemicals is an interesting proposition to mitigate its negative impact. However, the chemical inertness of CO2 presents a challenge to its transformation into useful chemicals. Transition metal complexes supported by pincer ligands have proved successful previously for the activation of small molecules. Here, we report our investigations into the use of a Pd^I –Pd^I dimer [(^FPNP)Pd]2, previously utilized by our group to activate molecules such as H2O, H2, NH3, O2, and to transform CO2 into CO, a more widely used C1-feedstock for chemicals. Use of trimethylsilyl reagents proved vital for O-atom abstraction to produce CO, and an in-house CO trap, (^MePNP)Ir(Ph)(H) was used to quantify the amount of CO evolved. Transition metal catalyzed cross coupling reactions have made synthesis of previously unattainable substrates possible, thus opening new avenues into new specialty chemicals, pharmaceuticals and agro chemicals. Group 10 metals, especially Pd have been used almost exclusively for these reactions in the past. The reasons for the popularity of these Pd catalysts are the versatility, functional group tolerance and wide substrate scope exhibited by them. More recently, however, metals outside group 10 such as Cu, Ir, Rh have found uses in these reactions. Especially, (POCOP)Rh systems previously reported by our group have been very useful in catalysis and mechanistic studies. Based on the success of these Rh catalysts and high natural abundance and low prices of cobalt, we envisioned the use of analogous Co systems as catalysts for catalytic cross coupling. With that as our primary goal, Co^III complexes such as (POCOP)Co(Ar)(X) and (POCOP)Co(Ar)(SAr’) presumed to be part of the catalytic C-S couplingcycle have been isolated and their interchange has been probed. However, contrary to the observations in Rh, C-S RE is not observed in the thermolysis of (POCOP)Co(Ar)(SAr’); instead CArCligand is the predominant reaction. A shift to the PNP ligands was made and indeed C-S RE is observed although accompanied by decomposition to (PNP)Co^II species. A relatively unexplored way of incorporating new functionality into pincer transition metal complexes is having multi-nuclear pincers that can be connected by different linkers to influence the degree of proximity and in turn the cooperativity between multiple metal sites. Such cooperativity can prove beneficial for reactions where one metal center is not enough. Here we have expanded the library of binucelar pincer ligands and complexes by reporting ligands of different steric bulk, linkers with incorporated functionality, and also metalation of these pincers with Ni and Pd. Advisors/Committee Members: Ozerov, Oleg V (advisor), Gabbai, Francois P (advisor), Hall, Michael B (committee member), Holtzapple, Mark T (committee member).

Subjects/Keywords: Cobalt; pincer; reduction of carbon dioxide; cross coupling; catalysis; binuclear pincers; POCOP; PNP; organometallic

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Palit, C. M. (2016). Novel Pincer Complexes of Transition Metals for Reduction of Carbon Dioxide to Carbon Monoxide and Cross Coupling of Aryl Halides. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/158095

Chicago Manual of Style (16^th Edition):

Palit, Chandra Mouli. “Novel Pincer Complexes of Transition Metals for Reduction of Carbon Dioxide to Carbon Monoxide and Cross Coupling of Aryl Halides.” 2016. Doctoral Dissertation, Texas A&M University. Accessed April 10, 2021. http://hdl.handle.net/1969.1/158095.

MLA Handbook (7^th Edition):

Palit, Chandra Mouli. “Novel Pincer Complexes of Transition Metals for Reduction of Carbon Dioxide to Carbon Monoxide and Cross Coupling of Aryl Halides.” 2016. Web. 10 Apr 2021.

Vancouver:

Palit CM. Novel Pincer Complexes of Transition Metals for Reduction of Carbon Dioxide to Carbon Monoxide and Cross Coupling of Aryl Halides. [Internet] [Doctoral dissertation]. Texas A&M University; 2016. [cited 2021 Apr 10]. Available from: http://hdl.handle.net/1969.1/158095.

Council of Science Editors:

Palit CM. Novel Pincer Complexes of Transition Metals for Reduction of Carbon Dioxide to Carbon Monoxide and Cross Coupling of Aryl Halides. [Doctoral Dissertation]. Texas A&M University; 2016. Available from: http://hdl.handle.net/1969.1/158095

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