+publisher:"Georgia Tech" +contributor:("Realff, Matthew J.")

1. Van Pelt, Adam Henderson. Stability of acid-modified activated carbons in hot liquid water and their application to biomass hydrolysis reactions.

Degree: MS, Chemical Engineering, 2013, Georgia Tech

URL: http://hdl.handle.net/1853/52024

► In this work, the stability of acid-modified activated carbons is assessed in the typical biomass conversion reaction environment of 200 °C, 17 bar water. Activated… (more)

▼ In this work, the stability of acid-modified activated carbons is assessed in the typical biomass conversion reaction environment of 200 °C, 17 bar water. Activated carbons were modified with a variety of common liquid and gas phase methods and characterized. Acid-modified carbon catalysts were exposed to hot liquid water for 24 h and further characterized to determine the effect of this exposure on their surface chemistry. It was found that the liquid phase acidifying agents of H₂SO₄ and HNO₃ are most effective at adding acidic functionalities to the carbon. Exposure to hot liquid water was found to significantly decrease the carboxylic and sulphonic acid site concentrations on the carbons and slightly increased lactonic group concentrations. Kinetic studies indicate that these surface chemical changes occur within the first 4 h exposure to this environment, and that increased exposure temperature results in more efficient acid site removal. XPS measurements show that H₂SO₄ modification imparts partially stable sulfonic acid groups on the carbon surface while HNO₃ modification imparts nitro groups which are unstable at exposure temperatures above 150 °C. The second part of this work focuses on the application of these acid-modified activated carbon catalysts as well as a variety of mixed metal oxide catalysts to the hydrolysis of the model biomass compound cellobiose. Catalyst screening reactions indicate that amorphous silica alumina catalysts are stable and selective but only slightly active whereas silica niobia catalysts are highly active but less selective and stable. Modified activated carbon catalysts were found to have moderate activity and selectivity. An investigation into the mechanism of silica niobia deactivation was performed and apparent activation energies were found for cellobiose hydrolysis over a variety of mixed metal oxide catalysts. Finally, a novel activated carbon synthesis mechanism was developed based on knowledge of surface site stability. This carbon catalyst was found to be highly active, selective, and stable for cellobiose hydrolysis but further characterization is required to fully understand its effectiveness as a catalyst. Advisors/Committee Members: Sievers, Carsten (advisor), Meredith, Carson (committee member), Realff, Matthew J. (committee member).

Subjects/Keywords: Activated carbon; Catalysis; Biomass; Biomass; Hydrolysis; Carbon, Activated; Acids

10 more images…

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Van Pelt, A. H. (2013). Stability of acid-modified activated carbons in hot liquid water and their application to biomass hydrolysis reactions. (Masters Thesis). Georgia Tech. Retrieved from http://hdl.handle.net/1853/52024

Chicago Manual of Style (16^th Edition):

Van Pelt, Adam Henderson. “Stability of acid-modified activated carbons in hot liquid water and their application to biomass hydrolysis reactions.” 2013. Masters Thesis, Georgia Tech. Accessed April 11, 2021. http://hdl.handle.net/1853/52024.

MLA Handbook (7^th Edition):

Van Pelt, Adam Henderson. “Stability of acid-modified activated carbons in hot liquid water and their application to biomass hydrolysis reactions.” 2013. Web. 11 Apr 2021.

Vancouver:

Van Pelt AH. Stability of acid-modified activated carbons in hot liquid water and their application to biomass hydrolysis reactions. [Internet] [Masters thesis]. Georgia Tech; 2013. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/1853/52024.

Council of Science Editors:

Van Pelt AH. Stability of acid-modified activated carbons in hot liquid water and their application to biomass hydrolysis reactions. [Masters Thesis]. Georgia Tech; 2013. Available from: http://hdl.handle.net/1853/52024

Georgia Tech

2. Kwok, Thomas Tai-min. Process engineering for lignin value prior to pulping.

Degree: PhD, Chemical and Biomolecular Engineering, 2019, Georgia Tech

URL: http://hdl.handle.net/1853/62663

► Biomass pretreatment unlocks chemical moieties for downstream valorization. This thesis focuses on organic solvent pretreatments that complement pulp production by delivering an additional lignin stream… (more)

Subjects/Keywords: Lignocellulosic biomass; Techno-economics; Lignin value prior to pulping; Solvent selection; Delignification; Pretreatment; Pulping; Organosolv

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Kwok, T. T. (2019). Process engineering for lignin value prior to pulping. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/62663

Chicago Manual of Style (16^th Edition):

Kwok, Thomas Tai-min. “Process engineering for lignin value prior to pulping.” 2019. Doctoral Dissertation, Georgia Tech. Accessed April 11, 2021. http://hdl.handle.net/1853/62663.

MLA Handbook (7^th Edition):

Kwok, Thomas Tai-min. “Process engineering for lignin value prior to pulping.” 2019. Web. 11 Apr 2021.

Vancouver:

Kwok TT. Process engineering for lignin value prior to pulping. [Internet] [Doctoral dissertation]. Georgia Tech; 2019. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/1853/62663.

Council of Science Editors:

Kwok TT. Process engineering for lignin value prior to pulping. [Doctoral Dissertation]. Georgia Tech; 2019. Available from: http://hdl.handle.net/1853/62663

Georgia Tech

3. Sinha, Anshuman. Systems design and uncertainty quantification of co2 capture from air.

Degree: PhD, Chemical and Biomolecular Engineering, 2018, Georgia Tech

URL: http://hdl.handle.net/1853/60214

► The rapid increase in concentration of atmospheric CO2 has stimulated the recent development of CO2 capture technologies. One of the strategy is to capture CO2… (more)

▼ The rapid increase in concentration of atmospheric CO2 has stimulated the recent development of CO2 capture technologies. One of the strategy is to capture CO2 directly from ambient air which, if successfully implemented, could result in capture of CO2 from disperse emission sources. My work proposes comparison of adsorbents for Direct Air Capture (DAC) through temperature vacuum swing adsorption (TVSA). The adsorbents are grown as films inside monolith contactors which offer low pressure drop during the adsorption step. A cyclic steady state process has been simulated and detailed techno-economic study has been performed on DAC. I have identified sensitive parameters such as gas flow rate, cycle time, adsorbent purchase cost, which effects the overall energy requirements and net economics of the Direct Air Capture process. Another area of CO2 capture is enclosed environments. Removal of CO2 from enclosed environment, such as commercial buildings is also of critical importance, primarily due to health risks associated with high CO2 concentration (>0.5%). In this study, I have designed and modeled a modified air conditioning system which regulates temperature as well as air quality inside an enclosed environment. The model is simulated on a 24 hour timescale including time varying human occupancy of the room. The system is optimized keeping realistic constraint as per ASHRAE standards to maintain a complex state of CO2, O2 and humidity levels with operation of air flow through different beds and recirculation. The optimized model shows improvement in performance as compared with conventional ventilation systems. CO2 capture systems have been modeled by understanding the physical process and solving coupled heat and mass balances equations through numerical simulators. Model parameters such as mass transfer coefficient, inlet flow rates etc. often remains uncertain due to lack of precise measurement as well as incomplete information. The accuracy of model outputs and performance metrics such as the net energy and cost can be questioned because of these parametric uncertainties. Hence, quantification of these uncertainties is necessary for more useful model predictions. I have employed Polynomial Chaos Expansion (PCE) methods (intrusive and non-intrusive) to quantify model uncertainty and compared it with Monte Carlo Simulations (MCS). Galerkin method is used to solve intrusive case, Latin Hypercube is used as sampling method and Nataf transformations are used for handling correlations in random variables. The PCE methods have shown better performance in terms of computational time, as compared to MCS. The intrusive PCE method shows higher complexity in model formulation but reduced computational time as compared to non-intrusive PCE method. In order to model all these systems, partial differential algebraic equations have been implemented in gPROMS, which is a commercial dynamic process modeling and optimization software. Linear driving force (LDF) model is used to approximate the rate of CO2 adsorption. Further,… Advisors/Committee Members: Realff, Matthew J. (advisor), Kawajiri, Yoshiaki (advisor), Sholl, David S. (committee member), Jones, Christopher W. (committee member), Shi, Jianjun (committee member).

Subjects/Keywords: Direct air capture; Uncertainty quantification; Metal organic frameworks; Polynomial chaos expansion

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Sinha, A. (2018). Systems design and uncertainty quantification of co2 capture from air. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/60214

Chicago Manual of Style (16^th Edition):

Sinha, Anshuman. “Systems design and uncertainty quantification of co2 capture from air.” 2018. Doctoral Dissertation, Georgia Tech. Accessed April 11, 2021. http://hdl.handle.net/1853/60214.

MLA Handbook (7^th Edition):

Sinha, Anshuman. “Systems design and uncertainty quantification of co2 capture from air.” 2018. Web. 11 Apr 2021.

Vancouver:

Sinha A. Systems design and uncertainty quantification of co2 capture from air. [Internet] [Doctoral dissertation]. Georgia Tech; 2018. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/1853/60214.

Council of Science Editors:

Sinha A. Systems design and uncertainty quantification of co2 capture from air. [Doctoral Dissertation]. Georgia Tech; 2018. Available from: http://hdl.handle.net/1853/60214

Georgia Tech

4. Encarnacion-Gomez, Luis G. Design and operation of enzymatic reactive crystallization: Applications in chiral purity and kinetically controlled synthesis.

Degree: PhD, Chemical and Biomolecular Engineering, 2015, Georgia Tech

URL: http://hdl.handle.net/1853/54322

► The work presented in this thesis is aimed to design efficient reactive crystallization operations that could potentially be implemented in the manufacture of enantiomerically pure… (more)

▼ The work presented in this thesis is aimed to design efficient reactive crystallization operations that could potentially be implemented in the manufacture of enantiomerically pure compounds and β-lactam antibiotics. Multiple aspects of solution thermodynamics, reaction engineering and crystallization from complex solutions are involved and will be discussed in detail through the following chapters. The first piece of this work utilizes reactive crystallization for the manufacture of enantiomerically pure amino acids. Chemo-enzymatic stereoiversion reactions are used to enrich saturated or supersaturated solutions to favor the selection of a desired enantiomer. L-Methionine and L-Phenylalanine were resolve successfully from racemic mixtures by cyclic stereoinversion. r D-amino acids were oxidized by D-amino acid oxidase (D-AAO) and the resulting ketoacid was subsequently reduced by ammonia borane producing a racemic-mixture After the necessary enantiomeric enrichment was reached, system conditions were changed to induce supersaturation and promote crystal formation. In each case crystals with chemical and enantiomeric purities greater than 99% wt. were recovered. experimental information about reaction and crystallization kinetics was used to developed models. Such models were used to design model-based optimizations in which the productivity of the operation was enhanced by selecting an optimal temperature profile. The second example is a reactive crystallization towards the manufacture of β-lactam antibiotics. One of the major drawbacks of the utilization of enzymes towards the manufacture of β-lactam antibiotics is the fact that the same enzyme that catalyzes the synthesis of the antibiotic also catalyzes its hydrolysis and thus, its degradation. The reaction scheme is a kinetically controlled synthesis in which the desired product is an intermediate within the network. Hence, the focus of this work is to design an efficient reactive crystallization in which the product is crystallized before it is consumed by hydrolysis. In order to accomplish this goal we have study solution equilibria, reaction kinetics, and crystallization kinetics. Even though crystallization kinetics of ampicillin has been previously reported; the reported models are not applicable to a reactive crystallization scheme for a variety of reasons. In this work, we have developed a robust model that can be applied to multiple crystallization protocols that are consistent with the conditions at which the enzymatic reaction can be performed. Finally, a reactive-crystallization scheme in which ampicillin was successfully recovered from solution was developed. In this work, crystal seeds were used to promote crystallization of the desired product from the complex media. The results indicated that is possible to perform the reaction and crystallization in parallel, and still recover crystals with high purity. This work is the first example in which ampicillin was produced and recovered with high purity in a single stage. Previous work on… Advisors/Committee Members: Rousseau, Ronald W. (advisor), Bommarius, Andreas S. (committee member), Kawajiri, Yoshiaki (committee member), Realff, Matthew J. (committee member), Liotta, Charles (committee member).

Subjects/Keywords: Crystallization; Reactive-crystallization; Enantiomers; Antibiotics

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Encarnacion-Gomez, L. G. (2015). Design and operation of enzymatic reactive crystallization: Applications in chiral purity and kinetically controlled synthesis. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/54322

Chicago Manual of Style (16^th Edition):

Encarnacion-Gomez, Luis G. “Design and operation of enzymatic reactive crystallization: Applications in chiral purity and kinetically controlled synthesis.” 2015. Doctoral Dissertation, Georgia Tech. Accessed April 11, 2021. http://hdl.handle.net/1853/54322.

MLA Handbook (7^th Edition):

Encarnacion-Gomez, Luis G. “Design and operation of enzymatic reactive crystallization: Applications in chiral purity and kinetically controlled synthesis.” 2015. Web. 11 Apr 2021.

Vancouver:

Encarnacion-Gomez LG. Design and operation of enzymatic reactive crystallization: Applications in chiral purity and kinetically controlled synthesis. [Internet] [Doctoral dissertation]. Georgia Tech; 2015. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/1853/54322.

Council of Science Editors:

Encarnacion-Gomez LG. Design and operation of enzymatic reactive crystallization: Applications in chiral purity and kinetically controlled synthesis. [Doctoral Dissertation]. Georgia Tech; 2015. Available from: http://hdl.handle.net/1853/54322

Georgia Tech

5. Harper, Richard Eugene. Development of novel synthetic turf infill materials.

Degree: PhD, Materials Science and Engineering, 2015, Georgia Tech

URL: http://hdl.handle.net/1853/54346

► Mitigation of health and heat-build-up issues related to black, granulated crumb rubber infill (GCRI) in synthetic turf fields (STF) while maintaining acceptable impact absorption properties… (more)

Subjects/Keywords: Rubber; Infill; Synthetic turf; Gmax; Impact

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Harper, R. E. (2015). Development of novel synthetic turf infill materials. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/54346

Chicago Manual of Style (16^th Edition):

Harper, Richard Eugene. “Development of novel synthetic turf infill materials.” 2015. Doctoral Dissertation, Georgia Tech. Accessed April 11, 2021. http://hdl.handle.net/1853/54346.

MLA Handbook (7^th Edition):

Harper, Richard Eugene. “Development of novel synthetic turf infill materials.” 2015. Web. 11 Apr 2021.

Vancouver:

Harper RE. Development of novel synthetic turf infill materials. [Internet] [Doctoral dissertation]. Georgia Tech; 2015. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/1853/54346.

Council of Science Editors:

Harper RE. Development of novel synthetic turf infill materials. [Doctoral Dissertation]. Georgia Tech; 2015. Available from: http://hdl.handle.net/1853/54346

Georgia Tech

6. Kang, Yuzhi. Biomass pretreatment toward efficient hydrolysis for sustainable biofuel applications.

Degree: PhD, Chemical and Biomolecular Engineering, 2015, Georgia Tech

URL: http://hdl.handle.net/1853/54852

► The production of biofuels from non-edible plant biomass has been necessitated by the concern for the environmental consequences of fossil fuel use and the tightening… (more)

▼ The production of biofuels from non-edible plant biomass has been necessitated by the concern for the environmental consequences of fossil fuel use and the tightening of supply and demand for liquid fuels. In contrast to first generation biofuels which rely on crops used for food supplies, second generation biofuels, derived from lignin-containing feedstocks, completely eliminate the competition for food. The major challenges associated with second generation biofuels are both technical and economic. Due to the recalcitrant nature of the raw biomass materials to further biological conversion, their structural degradation often requires severe and costly pretreatment processes such as heat, physical and chemical treatments to disturb and fractionate the biomass. Significant research effort has been devoted to understanding the recalcitrant nature and to accelerate the commercialization process of second generation biofuels. In this thesis, three pretreatment methods that belong to different categories have been investigated to understand their impacts on cellulose and/or lignocellulose and the subsequent hydrolysis steps. Physicochemical pretreatments, such as steam explosion, have been identified as one of the most effective and cost-efficient pretreatment methods for lignocelluosic materials. In Chapter 2, SO2-catalyzed steam explosion will be discussed and the effect of pretreatment severity on the substrate characteristics and degradation efficiency is also elucidated. Although the crystallinity index (CrI) of cellulose decreases as the severity increases, significant non-specific degradation and low yield of cellulose was observed at high severity. A new method for cellulose CrI determination has been developed with least squares curve fitting and validated with mechanically mixed cellulose samples. Biological pretreatment is another pathway through which the biomass structure can be modified to obtain a more amenable state for enzymatic degradation. Cellulose-binding domain (CBD) originated from Trichoderma reesei Cel7A (i.e. Tr cellobiohydrolase I) has been discovered as a potential biological pretreatment agent which is capable of modifying cellulose crystal structure. An extensive study on the protein engineering, expression, purification and functionalities of Cel7A CBDs was carried out (Chapter 3). The target mutations were identified with a computational protein engineering method involving principal component analysis (PCA). Due to the lack of catalytic activity and high throughput screening method, the library size was limited to nine. The wild-type and mutated CBDs were compared for their adsorption behavior and decrystallization effect on cellulose. Resulting saccharification efficiency after CBD pretreatment were studied and a possible explanation for the rate enhancement was proposed. In addition to physicochemical and biological pretreatment methods, chemical pretreatment is also a commonly employed method to overcome the recalcitrance of lignocellulosic materials. The most widely studied… Advisors/Committee Members: Bommarius, Andreas S. (advisor), Realff, Matthew J. (advisor), Lee, Jay H. (committee member), Peralta-Yahya, Pamela (committee member), Doran-Peterson, Joy (committee member).

Subjects/Keywords: Biofuels; Pretreatment

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Kang, Y. (2015). Biomass pretreatment toward efficient hydrolysis for sustainable biofuel applications. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/54852

Chicago Manual of Style (16^th Edition):

Kang, Yuzhi. “Biomass pretreatment toward efficient hydrolysis for sustainable biofuel applications.” 2015. Doctoral Dissertation, Georgia Tech. Accessed April 11, 2021. http://hdl.handle.net/1853/54852.

MLA Handbook (7^th Edition):

Kang, Yuzhi. “Biomass pretreatment toward efficient hydrolysis for sustainable biofuel applications.” 2015. Web. 11 Apr 2021.

Vancouver:

Kang Y. Biomass pretreatment toward efficient hydrolysis for sustainable biofuel applications. [Internet] [Doctoral dissertation]. Georgia Tech; 2015. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/1853/54852.

Council of Science Editors:

Kang Y. Biomass pretreatment toward efficient hydrolysis for sustainable biofuel applications. [Doctoral Dissertation]. Georgia Tech; 2015. Available from: http://hdl.handle.net/1853/54852

Georgia Tech

7. Griffin, Daniel J. A framework for understanding and controlling batch cooling crystallization.

Degree: PhD, Chemical and Biomolecular Engineering, 2016, Georgia Tech

URL: http://hdl.handle.net/1853/55619

► In taking a different view of crystallization dynamics, this thesis reveals a new framework for addressing a prevalent process engineering challenge: control over the size… (more)

Subjects/Keywords: Batch cooling crystallization; Crystal size control; Process analytical technology; Mass-count plot; Focused beam reflectance measurements; FBRM; Attenuated total reflectance Fourier transform infrared; ATR-FTIRpopulation balance; Population balance; Dynamic programming; Optimal control; Model predictive control; Machine learning; Learning from datadata-driven learning; Data-driven learning; Feedback control

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Griffin, D. J. (2016). A framework for understanding and controlling batch cooling crystallization. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/55619

Chicago Manual of Style (16^th Edition):

Griffin, Daniel J. “A framework for understanding and controlling batch cooling crystallization.” 2016. Doctoral Dissertation, Georgia Tech. Accessed April 11, 2021. http://hdl.handle.net/1853/55619.

MLA Handbook (7^th Edition):

Griffin, Daniel J. “A framework for understanding and controlling batch cooling crystallization.” 2016. Web. 11 Apr 2021.

Vancouver:

Griffin DJ. A framework for understanding and controlling batch cooling crystallization. [Internet] [Doctoral dissertation]. Georgia Tech; 2016. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/1853/55619.

Council of Science Editors:

Griffin DJ. A framework for understanding and controlling batch cooling crystallization. [Doctoral Dissertation]. Georgia Tech; 2016. Available from: http://hdl.handle.net/1853/55619

Georgia Tech

8. Tang, Xun. Markov state model-based optimal control for colloidal self-assembly.

Degree: PhD, Chemical and Biomolecular Engineering, 2016, Georgia Tech

URL: http://hdl.handle.net/1853/56276

► Colloidal self-assembly is widely studied as a promising route to manufacture highly ordered structures for applications as metamaterials. While near-equilibrium self-assembly could produce defect-free crystal,… (more)

▼ Colloidal self-assembly is widely studied as a promising route to manufacture highly ordered structures for applications as metamaterials. While near-equilibrium self-assembly could produce defect-free crystal, the time required is usually unmanageable in practical applications. On the contrary, rapid assembly via out-of-equilibrium approaches could reduce the amount of process time, but the assembled structure is usually terminated in defective states. Therefore, a gap exists between the speed and the quality of the structure in a colloidal self-assembly system. To overcome this challenge, this thesis proposes a model-based optimization framework for optimal feedback control over a colloidal self-assembly process for rapid assembly of defect-free two-dimensional crystals. The proposed framework features: first, the use of an externally applied electric field as a global actuator to influence the particle movement; second, the use of two order parameters to represent the high-dimensional system in a reduced dimension state space; third, the use of the Markov state model to capture the stochasticity in the system; fourth, the use of dynamic programming to design the optimal control policy; and fifth, the use of an optical microscope for in situ measurements as feedback. The feasibility of the framework is first demonstrated with a static optimal control policy, and its performance is evaluated against fast quench and near-equilibrium approaches. The framework is then expanded to construct a time-dependent optimal control policy, and the performance is compared with widely used time-varying control strategies in both simulation and experiments. The refinement of the framework, more specifically, the construction of the Markov state model is also revisited for better efficiency. The major contributions of this thesis include: (1) it proposes a novel approach to rapidly control colloidal self-assembly processes for perfect crystal with optimal control theories; (2) it demonstrates for the first time in lab, the realization of optimal feedback control of a colloidal self-assembly process; (3) it reveals the benefits of feedback in a stochastic process control, not only to compensate for model inaccuracy, but also to shorten the process time; (4) it also investigates the Markov state model accuracy and provides a more efficient construction of accurate Markov state models. The framework in this study is built on first-principle concepts, and it can be generalized to any molecular, nano-, or micro-scale assembly process where there exists a global actuator to affect the dynamics, a model to represent the relation between the actuator and the system, and a measurement of system state for feedback. Since micron-sized colloidal particles also serve as model systems to study the phase transition behavior and crystallization kinetics for atomic and molecular crystals, the framework can also be extended to these systems for optimal control. Advisors/Committee Members: Grover, Martha A. (advisor), Behrens, Sven Holger (committee member), Kawajiri, Yoshiaki (committee member), Realff, Matthew J. (committee member), Zhang, Fumin (committee member).

Subjects/Keywords: Markov state model; Optimal control; Dynamic programming; Colloidal self-assembly; Colloidal self assembly; Reduced order modeling

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Tang, X. (2016). Markov state model-based optimal control for colloidal self-assembly. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/56276

Chicago Manual of Style (16^th Edition):

Tang, Xun. “Markov state model-based optimal control for colloidal self-assembly.” 2016. Doctoral Dissertation, Georgia Tech. Accessed April 11, 2021. http://hdl.handle.net/1853/56276.

MLA Handbook (7^th Edition):

Tang, Xun. “Markov state model-based optimal control for colloidal self-assembly.” 2016. Web. 11 Apr 2021.

Vancouver:

Tang X. Markov state model-based optimal control for colloidal self-assembly. [Internet] [Doctoral dissertation]. Georgia Tech; 2016. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/1853/56276.

Council of Science Editors:

Tang X. Markov state model-based optimal control for colloidal self-assembly. [Doctoral Dissertation]. Georgia Tech; 2016. Available from: http://hdl.handle.net/1853/56276

9. Vasilakos, Petros. A decade of emissions controls and their role on an ever-changing atmosphere.

Degree: PhD, Chemical and Biomolecular Engineering, 2018, Georgia Tech

URL: http://hdl.handle.net/1853/61133

► The impact of emission controls in the decade 2001-2011 has been studied using a variety of models, that were updated to increase their predictive accuracy… (more)

Subjects/Keywords: Radioactive charging; CMAQ; SOA; Isoprene; IEPOX; Aerosol pH; Acidity; Sensitivity; DDM; ISORROPIA; Nitrate; Ozone; PM2.5; Emission reductions

11 more images…

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Vasilakos, P. (2018). A decade of emissions controls and their role on an ever-changing atmosphere. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/61133

Chicago Manual of Style (16^th Edition):

Vasilakos, Petros. “A decade of emissions controls and their role on an ever-changing atmosphere.” 2018. Doctoral Dissertation, Georgia Tech. Accessed April 11, 2021. http://hdl.handle.net/1853/61133.

MLA Handbook (7^th Edition):

Vasilakos, Petros. “A decade of emissions controls and their role on an ever-changing atmosphere.” 2018. Web. 11 Apr 2021.

Vancouver:

Vasilakos P. A decade of emissions controls and their role on an ever-changing atmosphere. [Internet] [Doctoral dissertation]. Georgia Tech; 2018. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/1853/61133.

Council of Science Editors:

Vasilakos P. A decade of emissions controls and their role on an ever-changing atmosphere. [Doctoral Dissertation]. Georgia Tech; 2018. Available from: http://hdl.handle.net/1853/61133

Georgia Tech

10. Rose, Harrison B. Towards an enzymatic route to 2,5-furandicarboxylic acid.

Degree: PhD, Chemical and Biomolecular Engineering, 2018, Georgia Tech

URL: http://hdl.handle.net/1853/61151

► This research project explored the selection and development of an enzymatic route from the renewable feedstocks furfural and carbon dioxide to 2,5-furandicarboxylic acid, a building… (more)

Subjects/Keywords: 2,5-furandicarboxylic acid; pH equilibria; Biocatalysis

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Rose, H. B. (2018). Towards an enzymatic route to 2,5-furandicarboxylic acid. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/61151

Chicago Manual of Style (16^th Edition):

Rose, Harrison B. “Towards an enzymatic route to 2,5-furandicarboxylic acid.” 2018. Doctoral Dissertation, Georgia Tech. Accessed April 11, 2021. http://hdl.handle.net/1853/61151.

MLA Handbook (7^th Edition):

Rose, Harrison B. “Towards an enzymatic route to 2,5-furandicarboxylic acid.” 2018. Web. 11 Apr 2021.

Vancouver:

Rose HB. Towards an enzymatic route to 2,5-furandicarboxylic acid. [Internet] [Doctoral dissertation]. Georgia Tech; 2018. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/1853/61151.

Council of Science Editors:

Rose HB. Towards an enzymatic route to 2,5-furandicarboxylic acid. [Doctoral Dissertation]. Georgia Tech; 2018. Available from: http://hdl.handle.net/1853/61151

Georgia Tech

11. Darunte, Lalit A. Application of metal organic frameworks (MOFs) to capturing CO2 directly from air.

Degree: PhD, Chemical and Biomolecular Engineering, 2018, Georgia Tech

URL: http://hdl.handle.net/1853/61162

► Increased CO2 concentration in the atmosphere is increasingly linked to climate change. With the aim of developing next-generation carbon capture technologies; this thesis focuses on… (more)

Subjects/Keywords: Metal organic frameworks (MOFs); MIL-101(Cr); Mg2(dobpdc); PEI-800; Mmen; Equilibrium wave theory; Honeycomb monolith; Process analysis, Kinetics

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Darunte, L. A. (2018). Application of metal organic frameworks (MOFs) to capturing CO2 directly from air. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/61162

Chicago Manual of Style (16^th Edition):

Darunte, Lalit A. “Application of metal organic frameworks (MOFs) to capturing CO2 directly from air.” 2018. Doctoral Dissertation, Georgia Tech. Accessed April 11, 2021. http://hdl.handle.net/1853/61162.

MLA Handbook (7^th Edition):

Darunte, Lalit A. “Application of metal organic frameworks (MOFs) to capturing CO2 directly from air.” 2018. Web. 11 Apr 2021.

Vancouver:

Darunte LA. Application of metal organic frameworks (MOFs) to capturing CO2 directly from air. [Internet] [Doctoral dissertation]. Georgia Tech; 2018. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/1853/61162.

Council of Science Editors:

Darunte LA. Application of metal organic frameworks (MOFs) to capturing CO2 directly from air. [Doctoral Dissertation]. Georgia Tech; 2018. Available from: http://hdl.handle.net/1853/61162

Georgia Tech

12. Yang, Xuejiao. Rapid and Accurate Fault Detection for Uncertain Nonlinear Systems Using Advanced Set-Based State Estimation Techniques.

Degree: PhD, Chemical and Biomolecular Engineering, 2020, Georgia Tech

URL: http://hdl.handle.net/1853/64107

► In applications such as wind energy, industrial robotics, and chemical processing, increases in complexity and automation have made component malfunctions and other abnormal events (i.e.,… (more)

▼ In applications such as wind energy, industrial robotics, and chemical processing, increases in complexity and automation have made component malfunctions and other abnormal events (i.e., faults) an ever-present threat to safety and reliability. Thus, fault detection algorithms have become an essential feature of modern control systems, leading to significant decreases in downtime, maintenance costs, and catastrophic failures. However, while well-established statistical methods are effective in many cases, they often fail to make the critical distinction between faults and normal process disturbances. An attractive alternative is to exploit detailed process models that, at least in principle, can be used to characterize the outputs consistent with normal operation, providing a rigorous basis for fault detection. Methods that furnish a guaranteed enclosure of these outputs (e.g., using set-based state estimators) are particularly attractive because they eliminate the possibility of costly false alarms and provide better trade-offs between false alarms and missed faults. However, such methods are currently impractical for systems with strong nonlinearities or large uncertainties. For such systems, existing set-based estimation techniques often produce enclosures that are far too conservative to be useful for fault detection, or avoid this only at excessive computational cost. Thus, there is a critical need for advanced algorithms that can rapidly detect faults for realistic nonlinear systems, and do so rigorously in the presence of disturbances, measurement noise, and large model uncertainties. In this thesis, we develop an advanced set-based state estimation method for uncertain nonlinear systems, and demonstrate its application to provide fast and accurate fault detection for such systems. Our proposed estimation method is performed recursively in two steps. First, the prediction step computes an enclosure of the possible model outputs under uncertainty over one discrete time step. Next, the correction step uses the process measurements to update this enclosure by eliminating regions that are not consistent with the measurements. In contrast to existing set-based estimation methods, our prediction step makes use of our previously developed continuous-time differential inequalities (DI) method and extends it to discrete-time systems. The DI method uses very efficient interval computations, but is effective at mitigating some key sources of conservatism typically associated with such computations in discrete-time systems by exploiting redundant model equations, which can be easily found in many representative reaction and separation models. Moreover, we make use of past process measurements in a novel way in the prediction step, potentially leading to further improvements in bound accuracy. Our results demonstrate that, for a variety of systems of practical interest, the proposed prediction step in the state estimation algorithm leads to dramatically tighter enclosures of the states, with only modest additional… Advisors/Committee Members: Scott, Joseph K. (advisor), Grover, Martha A. (committee member), Styczynski, Mark P. (committee member), Realff, Matthew J. (committee member), Coogan, Samuel (committee member).

Subjects/Keywords: Set-based fault detection; reachability analysis; set-based state estimation

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Yang, X. (2020). Rapid and Accurate Fault Detection for Uncertain Nonlinear Systems Using Advanced Set-Based State Estimation Techniques. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/64107

Chicago Manual of Style (16^th Edition):

Yang, Xuejiao. “Rapid and Accurate Fault Detection for Uncertain Nonlinear Systems Using Advanced Set-Based State Estimation Techniques.” 2020. Doctoral Dissertation, Georgia Tech. Accessed April 11, 2021. http://hdl.handle.net/1853/64107.

MLA Handbook (7^th Edition):

Yang, Xuejiao. “Rapid and Accurate Fault Detection for Uncertain Nonlinear Systems Using Advanced Set-Based State Estimation Techniques.” 2020. Web. 11 Apr 2021.

Vancouver:

Yang X. Rapid and Accurate Fault Detection for Uncertain Nonlinear Systems Using Advanced Set-Based State Estimation Techniques. [Internet] [Doctoral dissertation]. Georgia Tech; 2020. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/1853/64107.

Council of Science Editors:

Yang X. Rapid and Accurate Fault Detection for Uncertain Nonlinear Systems Using Advanced Set-Based State Estimation Techniques. [Doctoral Dissertation]. Georgia Tech; 2020. Available from: http://hdl.handle.net/1853/64107

13. Kanchanalai, Pakkapol. New dehydration and pretreatment process for ethanol production from biomass.

Degree: PhD, Chemical and Biomolecular Engineering, 2015, Georgia Tech

URL: http://hdl.handle.net/1853/53559

► The cost of pretreatment process for saccharification from biomass and the cost of dilute ethanol purification are significant components of the overall cost for fuel… (more)

Subjects/Keywords: Bioethanol dehydration; Biomass; Acid hydrolysis; Optimization; Simulated moving bed chromatography

13 more images…

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Kanchanalai, P. (2015). New dehydration and pretreatment process for ethanol production from biomass. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/53559

Chicago Manual of Style (16^th Edition):

Kanchanalai, Pakkapol. “New dehydration and pretreatment process for ethanol production from biomass.” 2015. Doctoral Dissertation, Georgia Tech. Accessed April 11, 2021. http://hdl.handle.net/1853/53559.

MLA Handbook (7^th Edition):

Kanchanalai, Pakkapol. “New dehydration and pretreatment process for ethanol production from biomass.” 2015. Web. 11 Apr 2021.

Vancouver:

Kanchanalai P. New dehydration and pretreatment process for ethanol production from biomass. [Internet] [Doctoral dissertation]. Georgia Tech; 2015. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/1853/53559.

Council of Science Editors:

Kanchanalai P. New dehydration and pretreatment process for ethanol production from biomass. [Doctoral Dissertation]. Georgia Tech; 2015. Available from: http://hdl.handle.net/1853/53559

14. Reid, Korin J. M. Biorefienry network design under uncertainty.

Degree: PhD, Chemical and Biomolecular Engineering, 2015, Georgia Tech

URL: http://hdl.handle.net/1853/53580

► This work integrates perennial feedstock yield modeling using climate model data from current and future climate scenarios, land use datasets, transportation network data sets, Geographic… (more)

Subjects/Keywords: Optimization; Mixed integer linear programming; GIS; Climate; Biofuels; Renewable energy; Biorefinery network design

11 more images…

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Reid, K. J. M. (2015). Biorefienry network design under uncertainty. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/53580

Chicago Manual of Style (16^th Edition):

Reid, Korin J M. “Biorefienry network design under uncertainty.” 2015. Doctoral Dissertation, Georgia Tech. Accessed April 11, 2021. http://hdl.handle.net/1853/53580.

MLA Handbook (7^th Edition):

Reid, Korin J M. “Biorefienry network design under uncertainty.” 2015. Web. 11 Apr 2021.

Vancouver:

Reid KJM. Biorefienry network design under uncertainty. [Internet] [Doctoral dissertation]. Georgia Tech; 2015. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/1853/53580.

Council of Science Editors:

Reid KJM. Biorefienry network design under uncertainty. [Doctoral Dissertation]. Georgia Tech; 2015. Available from: http://hdl.handle.net/1853/53580

Georgia Tech

15. Park, Jongwoo. Atomistic characterization of metal-organic frameworks for sub-ambient pressure swing adsorption of post-combustion CO2 capture and separation.

Degree: PhD, Chemical and Biomolecular Engineering, 2019, Georgia Tech

URL: http://hdl.handle.net/1853/62308

► Developing cost-effective and less energy-intensive carbon capture processes for dilute CO2 sources is of high interest. Adsorption-based CO2 capture such as pressure swing adsorption (PSA)… (more)

▼ Developing cost-effective and less energy-intensive carbon capture processes for dilute CO2 sources is of high interest. Adsorption-based CO2 capture such as pressure swing adsorption (PSA) is one promising approach to this challenge. PSA and other cyclic adsorption processes are materials-enabled separations that use porous adsorbents, including metal-organic frameworks (MOFs). This thesis examines post-combustion carbon capture in sub-ambient PSA, a potential route to an effective adsorption process, using MOF materials via molecular modeling. We first estimated the reproducibility of CO2 adsorption isotherm measurements in MOFs via literature meta-analysis. This chapter provides a comprehensive summary of the state of knowledge regarding CO2 adsorption in MOFs and its implications for molecular modeling of adsorption in MOFs. We then examined the upper bounds on CO2 swing capacity in sub-ambient PSA by Grand Canonical Monte Carlo (GCMC) simulation of an extensive collection of MOFs. A wide variety of MOFs was found to have swing capacity exceeding 10 mol/kg at sub-ambient temperatures provided that MOFs are appropriately selected based on their physical properties. We also assessed the capability of simple proxies for adsorbent performance and approximate models of cyclic adsorption to predict the outcomes of detailed process models of adsorption-based CO2 capture processes. To this end, we discuss the correlations between predictions from the simpler models and detailed process models. As a separate contribution, molecular modeling of chemical warfare agents (CWAs) adsorption in MOFs was analyzed. Molecular models of adsorption of CO2, CWAs or other molecules typically employ a rigid framework approximation for computational convenience. All real frameworks including MOFs, however, have intrinsic flexibility due to thermal vibrations. We examine the implications of this simple observation for quantitative predictions of the properties of adsorbed CWAs. Advisors/Committee Members: Sholl, David S. (advisor), Lively, Ryan P. (committee member), Walton, Krista S. (committee member), Realff, Matthew J. (committee member), Gumbart, James C. (committee member).

Subjects/Keywords: CO2 adsorption; Metal-organic frameworks; Molecular modeling

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Park, J. (2019). Atomistic characterization of metal-organic frameworks for sub-ambient pressure swing adsorption of post-combustion CO2 capture and separation. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/62308

Chicago Manual of Style (16^th Edition):

Park, Jongwoo. “Atomistic characterization of metal-organic frameworks for sub-ambient pressure swing adsorption of post-combustion CO2 capture and separation.” 2019. Doctoral Dissertation, Georgia Tech. Accessed April 11, 2021. http://hdl.handle.net/1853/62308.

MLA Handbook (7^th Edition):

Park, Jongwoo. “Atomistic characterization of metal-organic frameworks for sub-ambient pressure swing adsorption of post-combustion CO2 capture and separation.” 2019. Web. 11 Apr 2021.

Vancouver:

Park J. Atomistic characterization of metal-organic frameworks for sub-ambient pressure swing adsorption of post-combustion CO2 capture and separation. [Internet] [Doctoral dissertation]. Georgia Tech; 2019. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/1853/62308.

Council of Science Editors:

Park J. Atomistic characterization of metal-organic frameworks for sub-ambient pressure swing adsorption of post-combustion CO2 capture and separation. [Doctoral Dissertation]. Georgia Tech; 2019. Available from: http://hdl.handle.net/1853/62308

Georgia Tech

16. Lee, Dong-Yeon. Parametric approach to life cycle assessment.

Degree: PhD, Civil and Environmental Engineering, 2016, Georgia Tech

URL: http://hdl.handle.net/1853/58181

► Life cycle assessment is a method to evaluate economic and environmental benefits and tradeoffs of technologies, human activities, and systems. Data gaps, variability, uncertainty, and… (more)

▼ Life cycle assessment is a method to evaluate economic and environmental benefits and tradeoffs of technologies, human activities, and systems. Data gaps, variability, uncertainty, and weak generalizability are among the continuing challenges in life cycle assessment. As a way of resolving these issues, a parametric life cycle assessment framework is proposed and demonstrated, using case studies of vehicle electrification and decentralized power generation for buildings. The parametric life cycle assessment involves investigating governing equations; identifying overall relationships between input and output variables; evaluating characteristics and typology of input and output variables; assessing relative importance and contribution of individual input parameters; and developing a parametric form of life cycle assessment models. For medium- and heavy-duty vehicles electrification, the results from the parametric life cycle assessment indicate that electric vehicles provide positive social benefits for niche applications or locations, regardless of the variations and uncertainties in input conditions including future electric grid evolution and fuel prices changes. Beyond the niche applications or locations, however, electrifying medium- and heavy-duty vehicles is not expected to provide positive net social benefits in the near future, in comparison with conventional technologies powered by petroleum, biofuels, or natural gas. Vehicle operation strategy modifications or a moderate level of electrification such as micro-hybrid technology can provide more immediate benefits. Using the same parametric LCA approach, life cycle tradeoffs of decentralized power generation technologies for buildings are systematically evaluated, including natural gas-based hydrogen fuel cell and microturbine technologies. Combined cooling, heating, and power provides numerous benefits including more efficient and stable electricity provision compared to conventional building energy systems. From the life cycle perspective, cogeneration or trigeneration technologies, in particular, microturbines help reduce air emissions and water consumption but at the expense of energy efficiency. Although fuel cell and microturbine technologies tend to move air emissions sources from less-populated locations to population centers, overall air pollution impacts across the U.S. are lower than for conventional systems. Depending on the building types, overall social benefits of these alternative and distributed power production technologies can vary. In general, achieving electric grid independence and improving resilience against power outage requires up to 50% higher valuation of reliable power production. Advisors/Committee Members: Thomas, Valerie M. (advisor), Crittenden, John C. (committee member), Mokhtarian, Patricia L. (committee member), Realff, Matthew J. (committee member), McCarthy, Patrick S. (committee member).

Subjects/Keywords: Life cycle assessment; Electric vehicles; Decentralized power generation; Trucks; Buses; Combined cooling, heating, and power

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Lee, D. (2016). Parametric approach to life cycle assessment. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/58181

Chicago Manual of Style (16^th Edition):

Lee, Dong-Yeon. “Parametric approach to life cycle assessment.” 2016. Doctoral Dissertation, Georgia Tech. Accessed April 11, 2021. http://hdl.handle.net/1853/58181.

MLA Handbook (7^th Edition):

Lee, Dong-Yeon. “Parametric approach to life cycle assessment.” 2016. Web. 11 Apr 2021.

Vancouver:

Lee D. Parametric approach to life cycle assessment. [Internet] [Doctoral dissertation]. Georgia Tech; 2016. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/1853/58181.

Council of Science Editors:

Lee D. Parametric approach to life cycle assessment. [Doctoral Dissertation]. Georgia Tech; 2016. Available from: http://hdl.handle.net/1853/58181

Georgia Tech

17. Agrawal, Gaurav. Systematic optimization and experimental validation of simulated moving bed chromatography systems for ternary separations and equilibrium limited reactions.

Degree: PhD, Chemical and Biomolecular Engineering, 2014, Georgia Tech

URL: http://hdl.handle.net/1853/54028

► Simulated Moving Bed (SMB) chromatography is a separation process where the components are separated due to their varying affinity towards the stationary phase. Over the… (more)

▼ Simulated Moving Bed (SMB) chromatography is a separation process where the components are separated due to their varying affinity towards the stationary phase. Over the past decade, many modifications have been proposed in SMB chromatography in order to effectively separate a binary mixture. However, the separation of multi-component mixtures using SMB is still one of the major challenges. Although many different strategies have been proposed, previous studies have rarely performed comprehensive investigations for finding the best ternary separation strategy from various possible alternatives. Furthermore, the concept of combining reaction with SMB has been proposed in the past for driving the equilibrium limited reactions to completion by separating the products from the reaction zone. However, the design of such systems is still challenging due to the complex dynamics of simultaneous reaction and adsorption. The first objective of the study is to find the best ternary separation strategy among various alternatives design of SMB. The performance of several ternary SMB operating schemes, that are proposed in the literature, are compared in terms of the optimal productivity obtained and the amount of solvent consumed. A multi- objective optimization problem is formulated which maximizes the SMB productivity and purity of intermediate eluting component at the same time. Furthermore, the concept of optimizing a superstructure formulation is proposed, where numerous SMB operating schemes can be incorporated into a single formulation. This superstructure approach has a potential to find more advantageous operating scheme compared to existing operating schemes in the literature. The second objective of the study is to demonstrate the Generalized Full Cycle (GFC) operation experimentally for the first time, and compare its performance to the JO process. A Semba OctaveTM chromatography system is used as an experimental SMB unit to implement the optimal operating schemes. In addition, a simultaneous optimization and model correction (SOMC) scheme is used to resolve the model mismatch in a systematic way. We also show a systematic comparison of both JO and GFC operations by presenting a Pareto plot of the productivity achieved against the desired purity of the intermediate eluting component experimentally. The third objective of the study is to develop an simulated moving bed reactor (SMBR) process for an industrial-scale application, and demonstrate the potential of the ModiCon operation for improving the performance of the SMBR compared to the conventional operating strategy. A novel industrial application involving the esterification of acetic acid and 1-methoxy-2-propanol is considered to produce propylene glycol methyl ether (PMA) as the product. A multi-objective optimization study is presented to find the best reactive separation strategy for the production of the PMA product. We also present a Pareto plot that compares the ModiCon operation, which allows periodical change of the feed composition and the… Advisors/Committee Members: Kawajiri, Yoshiaki (advisor), Realff, Matthew J. (committee member), Grover, Martha (committee member), Nenes, Athanasios (committee member), Bommarius, Andreas S. (committee member), Tsiotras, Panagiotis (committee member).

Subjects/Keywords: Simulated moving bed chromatography; Reactive separation; Parameter estimation; Modeling and optimization; Ternary separation

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Agrawal, G. (2014). Systematic optimization and experimental validation of simulated moving bed chromatography systems for ternary separations and equilibrium limited reactions. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/54028

Chicago Manual of Style (16^th Edition):

Agrawal, Gaurav. “Systematic optimization and experimental validation of simulated moving bed chromatography systems for ternary separations and equilibrium limited reactions.” 2014. Doctoral Dissertation, Georgia Tech. Accessed April 11, 2021. http://hdl.handle.net/1853/54028.

MLA Handbook (7^th Edition):

Agrawal, Gaurav. “Systematic optimization and experimental validation of simulated moving bed chromatography systems for ternary separations and equilibrium limited reactions.” 2014. Web. 11 Apr 2021.

Vancouver:

Agrawal G. Systematic optimization and experimental validation of simulated moving bed chromatography systems for ternary separations and equilibrium limited reactions. [Internet] [Doctoral dissertation]. Georgia Tech; 2014. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/1853/54028.

Council of Science Editors:

Agrawal G. Systematic optimization and experimental validation of simulated moving bed chromatography systems for ternary separations and equilibrium limited reactions. [Doctoral Dissertation]. Georgia Tech; 2014. Available from: http://hdl.handle.net/1853/54028

Georgia Tech

18. Dewitt, Stephen John Amon. Thermally Modulated Fiber Sorbents for Rapidly Cycled Vacuum-Pressure Swing Adsorption of Post-Combustion Flue Gas.

Degree: PhD, Chemical and Biomolecular Engineering, 2020, Georgia Tech

URL: http://hdl.handle.net/1853/64124

► Thermally Modulated Fiber Sorbents for Rapidly Cycled Vacuum Pressure Swing Adsorption of Post Combustion Flue Gas Stephen J.A. DeWitt 339 Pages Directed by Dr. Ryan… (more)

▼ Thermally Modulated Fiber Sorbents for Rapidly Cycled Vacuum Pressure Swing Adsorption of Post Combustion Flue Gas Stephen J.A. DeWitt 339 Pages Directed by Dr. Ryan P. Lively The continued rise in the concentration of CO2 in the Earth’s atmosphere driven by society’s rising standard of living and continued reliance on carbon-containing fossil fuels has led to several significant environmental challenges, which will continue to face humanity in the coming decades and centuries. Developing technological solutions to accelerate the reduction of carbon dioxide emissions and curtail the effects of climate change will continue to serve one of the critical directions society will pursue to combat these effects. The capture of CO2 from point sources like coal-fired power plants will likely be a direction for the short and long-term reduction in emissions needed to stabilize the environment. With this in mind, developing technologies to serve this purpose with the least impact on people’s way of life serves as a critical challenge over the coming decades. The removal of CO2 from point sources has been an area of interest for a number of years now, with absorption technology appears best suited to make an immediate impact with pilot and full-scale plants currently being built. In the future, methods of separating and capturing CO2 will look to technologies with the potential to be considerably lower energy requirements, like adsorption and membranes, and these are still in the early stages of development. While these approaches lag behind absorption in technology readiness for CO2 capture today, the potential impact of their adoption in terms of cost reduction has led to considerable research investment in developing new materials and processes to enable their application. In this dissertation, a novel strategy is proposed, and materials are developed to enable the proposed process for post-combustion CO2 capture from coal. As part of this dissertation, four objectives were pursued to understand and enable this process. xxvii i) A process model was created and studied to develop a deeper understanding of the approach’s potential and the necessary materials developments to enable it. ii) Promising materials were synthesized and manufactured into ready-made devices for bench-scale testing. iii) Fundamental challenges of adsorptive separations related to heat management were considered in detail, and a novel manufacturing approach was developed to enable improvement in materials performance. iv) The potential of fiber sorbents for sub-ambient CO2 capture was examined through the operation of single bed PSA cycles using the manufactured materials from previous objectives. The first objective showed that a sub-ambient pressure-driven separation process, coupled with downstream liquefaction, could be used without the need for external refrigeration. Excess low-quality cooling could also be used for the dehydration of the flue gas, a key challenge facing adsorptive CO2 capture. This process would be significantly limited by… Advisors/Committee Members: Jones, Christopher W (committee member), Sholl, David S (committee member), Realff, Matthew J (committee member), Wilkinson, Angus P (committee member), Agrawal, Pradeep (committee member).

Subjects/Keywords: CO2 Capture; Adsorption; Pressure Swing Adsorption; Fiber Sorbents

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Dewitt, S. J. A. (2020). Thermally Modulated Fiber Sorbents for Rapidly Cycled Vacuum-Pressure Swing Adsorption of Post-Combustion Flue Gas. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/64124

Chicago Manual of Style (16^th Edition):

Dewitt, Stephen John Amon. “Thermally Modulated Fiber Sorbents for Rapidly Cycled Vacuum-Pressure Swing Adsorption of Post-Combustion Flue Gas.” 2020. Doctoral Dissertation, Georgia Tech. Accessed April 11, 2021. http://hdl.handle.net/1853/64124.

MLA Handbook (7^th Edition):

Dewitt, Stephen John Amon. “Thermally Modulated Fiber Sorbents for Rapidly Cycled Vacuum-Pressure Swing Adsorption of Post-Combustion Flue Gas.” 2020. Web. 11 Apr 2021.

Vancouver:

Dewitt SJA. Thermally Modulated Fiber Sorbents for Rapidly Cycled Vacuum-Pressure Swing Adsorption of Post-Combustion Flue Gas. [Internet] [Doctoral dissertation]. Georgia Tech; 2020. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/1853/64124.

Council of Science Editors:

Dewitt SJA. Thermally Modulated Fiber Sorbents for Rapidly Cycled Vacuum-Pressure Swing Adsorption of Post-Combustion Flue Gas. [Doctoral Dissertation]. Georgia Tech; 2020. Available from: http://hdl.handle.net/1853/64124

19. Pandian Babu, Vinod Babu. High-solids, mixed-matrix hollow fiber sorbents for CO₂ capture.

Degree: PhD, Chemical and Biomolecular Engineering, 2014, Georgia Tech

URL: http://hdl.handle.net/1853/53435

► Post-combustion carbon capture, wherein the CO2 produced as a result of coal combustion is trapped at the power plant exhaust, is seen as a bridging… (more)

Subjects/Keywords: Solid sorbents; Hollow fiber sorbents; Mixed matrix fibers; Flue gas capture; Carbon capture; RTSA; Hollow fibers

10 more images…

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Pandian Babu, V. B. (2014). High-solids, mixed-matrix hollow fiber sorbents for CO₂ capture. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/53435

Chicago Manual of Style (16^th Edition):

Pandian Babu, Vinod Babu. “High-solids, mixed-matrix hollow fiber sorbents for CO₂ capture.” 2014. Doctoral Dissertation, Georgia Tech. Accessed April 11, 2021. http://hdl.handle.net/1853/53435.

MLA Handbook (7^th Edition):

Pandian Babu, Vinod Babu. “High-solids, mixed-matrix hollow fiber sorbents for CO₂ capture.” 2014. Web. 11 Apr 2021.

Vancouver:

Pandian Babu VB. High-solids, mixed-matrix hollow fiber sorbents for CO₂ capture. [Internet] [Doctoral dissertation]. Georgia Tech; 2014. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/1853/53435.

Council of Science Editors:

Pandian Babu VB. High-solids, mixed-matrix hollow fiber sorbents for CO₂ capture. [Doctoral Dissertation]. Georgia Tech; 2014. Available from: http://hdl.handle.net/1853/53435

20. Yeh, Kevin. Mathematical programming analyses of an established timberlands supply chain with interests in biofuel investments.

Degree: PhD, Chemical and Biomolecular Engineering, 2014, Georgia Tech

URL: http://hdl.handle.net/1853/53065

► In the push for clean and renewable fuels, timber derived biomass is a promising frontier for biofuel production in the United States. This thesis approaches… (more)

▼ In the push for clean and renewable fuels, timber derived biomass is a promising frontier for biofuel production in the United States. This thesis approaches the established timberlands biofuel implementation problem with three different mathematical programming studies, each testing feasibility and sustainability in different economic and supply related situations. In the first study, a competitive game theory approach was utilized to provide new insights into the behavior within a timberlands supply chain. We utilized Stackelberg game theory modeled with bilevel programming to represent the competing harvesting and manufacturing sectors. In the second study, the initial bilevel model was utilized in a larger two stage multiperiod model with parameter uncertainty. In this more realistic model, the first stage contained logistical decisions around biorefinery investments, such as location and capacity, while the second stage was composed of multiple discrete bilevel scenarios representing potential situations in the timberlands system. The final study focused on long term land management strategies for the timberlands supply chain. Introduction of a new biorefinery investment meant that management strategies must be altered to ensure consistent material flows to manufacturers as well as sustain the new production facility. A modified cyclic scheduling formulation was used to model a timberlands system and its planting and harvesting schedule to accommodate a new biorefinery. This cyclic model added an initial startup period to initiate biofuel production and provide time to adapt land management. The overall contribution of these studies was to analyze a biorefinery's impact on the established behavior in a timberlands supply chain. In particular, the goals of these models were to develop introductory decision making tools for timberlands supply chain managers. Advisors/Committee Members: Realff, Matthew J. (advisor), Lee, Jay H. (advisor), Grover, Martha (committee member), Kawajiri, Yoshiaki (committee member), Whittaker, Craig (committee member), Ammons, Jane C. (committee member).

Subjects/Keywords: Biofuels; Timberlands supply chain; Mathematical programming; Optimization; Stackelberg game theory; Cyclic scheduling; Bilevel programming; Multiperiod uncertainty; Two stage modeling

10 more images…

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Yeh, K. (2014). Mathematical programming analyses of an established timberlands supply chain with interests in biofuel investments. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/53065

Chicago Manual of Style (16^th Edition):

Yeh, Kevin. “Mathematical programming analyses of an established timberlands supply chain with interests in biofuel investments.” 2014. Doctoral Dissertation, Georgia Tech. Accessed April 11, 2021. http://hdl.handle.net/1853/53065.

MLA Handbook (7^th Edition):

Yeh, Kevin. “Mathematical programming analyses of an established timberlands supply chain with interests in biofuel investments.” 2014. Web. 11 Apr 2021.

Vancouver:

Yeh K. Mathematical programming analyses of an established timberlands supply chain with interests in biofuel investments. [Internet] [Doctoral dissertation]. Georgia Tech; 2014. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/1853/53065.

Council of Science Editors:

Yeh K. Mathematical programming analyses of an established timberlands supply chain with interests in biofuel investments. [Doctoral Dissertation]. Georgia Tech; 2014. Available from: http://hdl.handle.net/1853/53065

21. Kalyanaraman, Jayashree. Towards uncertainty quantification of complex chemical processes with application to post-combustion carbon capture.

Degree: PhD, Chemical and Biomolecular Engineering, 2017, Georgia Tech

URL: http://hdl.handle.net/1853/58310

► Quantifying the extent of model uncertainty is crucial in the technical feasibility analysis of energy technologies and can provide a significant saving of cost and… (more)

▼ Quantifying the extent of model uncertainty is crucial in the technical feasibility analysis of energy technologies and can provide a significant saving of cost and time. However, performing the uncertainty quantification for a complex chemical process involving coupled PDEs system is computationally prohibitive. Parallel algorithms and parallelization is utilized wherever possible in the entire framework of uncertainty quantification to handle the involved computational cost. The model complexity, on the other hand, is retained without resorting to any form of reduction or surrogate modeling. The application that is studied to perform the uncertainty analysis is the post-combustion carbon capture via Rapid Thermal Swing Adsorption using amine sorbents in a hollow fiber contactor. Thermal Swing Adsorption is a dynamic non-isothermal cyclic process with a complex interplay of mass transfer kinetics and equilibrium, and therefore the governing process model is a complex coupled system of PDEs. The process model developed is initially calibrated using conventional methods of parameter estimation and the performance is benchmarked for comparison against the results obtained incorporating uncertainties. The computational challenge in performing Bayesian inference, is handled by employing Sequential Monte Carlo, a parallel algorithm based on particle filtering. The uncertainties involved in the process are characterized using four different approaches, viz ”Hierinf”: the data are separated into subsets and the inference is performed for the individual series, ”Varinflat-inf”: the variance of the parametric uncertainties are increased by increasing the variance of the residual errors, ”Uresvar-inf”: wherein, additional model parameters are considered as uncertain in an attempt to reduce the residual variability (errors), ”Mdiscrep-inf”: wherein, the additional uncertainty is introduced in the model structure via the model discrepancy term. The characterized uncertainties, obtained from each of the four different approaches are propagated through the process model and the uncertainties in the key prediction variables, viz: the product quality and process performance, viz: CO2 swing capacity are obtained. The last component of uncertainty analysis is to be able to design experiments optimally in order to reduce the prediction uncertainties. A new method is proposed wherein the prediction uncertainty is reduced through designing experiments based on the utility function formulated with the parametric distributions. The proposed method is demonstrated for a simpler system of RTSA, in which only the adsorption isotherm paramters are considered as uncertain. Advisors/Committee Members: Realff, Matthew J. (committee member), Kawajiri, Yoshiaki (committee member), Jones, Christopher W. (committee member), Lively, Ryan P. (committee member), Vengazhiyil, Roshan J. (committee member).

Subjects/Keywords: Uncertainty quantification; Carbon capture; Hollow fiber; Adsorption

11 more images…

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Kalyanaraman, J. (2017). Towards uncertainty quantification of complex chemical processes with application to post-combustion carbon capture. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/58310

Chicago Manual of Style (16^th Edition):

Kalyanaraman, Jayashree. “Towards uncertainty quantification of complex chemical processes with application to post-combustion carbon capture.” 2017. Doctoral Dissertation, Georgia Tech. Accessed April 11, 2021. http://hdl.handle.net/1853/58310.

MLA Handbook (7^th Edition):

Kalyanaraman, Jayashree. “Towards uncertainty quantification of complex chemical processes with application to post-combustion carbon capture.” 2017. Web. 11 Apr 2021.

Vancouver:

Kalyanaraman J. Towards uncertainty quantification of complex chemical processes with application to post-combustion carbon capture. [Internet] [Doctoral dissertation]. Georgia Tech; 2017. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/1853/58310.

Council of Science Editors:

Kalyanaraman J. Towards uncertainty quantification of complex chemical processes with application to post-combustion carbon capture. [Doctoral Dissertation]. Georgia Tech; 2017. Available from: http://hdl.handle.net/1853/58310

22. Pas, Joshua W. Contract and strategic network design for reverse production systems.

Degree: PhD, Industrial and Systems Engineering, 2008, Georgia Tech

URL: http://hdl.handle.net/1853/22577

► A Reverse Production System (RPS) is a network of transportation logistics and processing functions that collects, refurbishes, and demanufactures for reuse/recycle used or end-of-life products.… (more)

Subjects/Keywords: Game theory; Recycling; Reverse production systems; Contract design; Strategic collection network design; Recycling (Waste, etc.); Refuse and refuse disposal; Refuse collection; Raw materials; Mathematical optimization

…Georgia Tech (Newton (2000) and 10 Assavapokee (2004)). With a…

10 more images…

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Pas, J. W. (2008). Contract and strategic network design for reverse production systems. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/22577

Chicago Manual of Style (16^th Edition):

Pas, Joshua W. “Contract and strategic network design for reverse production systems.” 2008. Doctoral Dissertation, Georgia Tech. Accessed April 11, 2021. http://hdl.handle.net/1853/22577.

MLA Handbook (7^th Edition):

Pas, Joshua W. “Contract and strategic network design for reverse production systems.” 2008. Web. 11 Apr 2021.

Vancouver:

Pas JW. Contract and strategic network design for reverse production systems. [Internet] [Doctoral dissertation]. Georgia Tech; 2008. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/1853/22577.

Council of Science Editors:

Pas JW. Contract and strategic network design for reverse production systems. [Doctoral Dissertation]. Georgia Tech; 2008. Available from: http://hdl.handle.net/1853/22577

23. Gupta, Kishor Kumar. Polyvinyl alcohol size recovery and reuse via vacuum flash evaporation.

Degree: PhD, Polymer, Textile and Fiber Engineering, 2009, Georgia Tech

URL: http://hdl.handle.net/1853/28181

► Polyvinyl alcohol (PVA) desize effluent is a high COD contributor to towel manufacturing plant's Primary Oxygenation Treatment of Water operation, and being non-biodegradable, is a… (more)

▼ Polyvinyl alcohol (PVA) desize effluent is a high COD contributor to towel manufacturing plant's Primary Oxygenation Treatment of Water operation, and being non-biodegradable, is a threat to the environment. When all-PVA/wax size is used in weaving, significant incentives exist to recover the synthetic polymer material from the desize wash water stream and reuse it. A new technology that would eliminate the disadvantages of the current Reverse Osmosis Ultrafiltration (UF) PVA recovery process is Vacuum Flash Evaporation (VFE). This research adapts the VFE process to the recovery and reuse of all-PVA size emanating from towel manufacturing, and compares the economics of its implementation in a model plant to current plant systems that use PVA/starch blend sizes with no materials/water recovery. After bench scale research optimized the VFE PVA recovery process from the desize effluent and determined the mass of virgin PVA that was required to be added to the final, recycled PVA size formulations. The physical changes in the recycled size film and yarn composite properties from those of the initial (conventional) slashing were determined using a number of characterization techniques, including DSC, TGA, SEM, tensile testing, viscometry, number of abrasion cycles to first yarn breaks, microscopy and contact angle measurements. Cotton chemical impurities extracted from the yarns during desizing played an important role in the recovered PVA film physical properties. The recovered PVA improved the slashed yarn weave ability. Along with recovered PVA, pure hot water was recovered from the VFE. Virgin wax adds to the final, recycled size formulations were determined to be unnecessary, as the impurities extracted into the desize effluent stream performed the same functions in the size as the wax. Using the bench results, the overall VFE process was optimized and demonstrated to be technically viable through six cycles, proof-of-concept trials conducted on a Webtex Continuous Pilot Slasher. Based on the pilot scale trials, comparative economics were developed. Incorporation of the VFE technology for PVA size recovery and recycling resulted in ~3.2M/year in savings over the conventional PVA/starch/wax process, yielding a raw ROI of less than one year based on a 3M turnkey capital investment. Advisors/Committee Members: Dr. Cook, Fred L. (Committee Chair), Dr. Carr, Wallace W. (Committee Member), Dr. Parachuru, Radhakrishnaiah (Committee Member), Dr. Realff, Matthew J. (Committee Member), Dr. Muzzy, John D. (Committee Member).

Subjects/Keywords: Cotton impurities; Recovery and reuse; Polyvinyl alcohol; Textile; Slashing; Vacuum flash evaporation; Textile industry; Viscosity; Elasticity

10 more images…

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Gupta, K. K. (2009). Polyvinyl alcohol size recovery and reuse via vacuum flash evaporation. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/28181

Chicago Manual of Style (16^th Edition):

Gupta, Kishor Kumar. “Polyvinyl alcohol size recovery and reuse via vacuum flash evaporation.” 2009. Doctoral Dissertation, Georgia Tech. Accessed April 11, 2021. http://hdl.handle.net/1853/28181.

MLA Handbook (7^th Edition):

Gupta, Kishor Kumar. “Polyvinyl alcohol size recovery and reuse via vacuum flash evaporation.” 2009. Web. 11 Apr 2021.

Vancouver:

Gupta KK. Polyvinyl alcohol size recovery and reuse via vacuum flash evaporation. [Internet] [Doctoral dissertation]. Georgia Tech; 2009. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/1853/28181.

Council of Science Editors:

Gupta KK. Polyvinyl alcohol size recovery and reuse via vacuum flash evaporation. [Doctoral Dissertation]. Georgia Tech; 2009. Available from: http://hdl.handle.net/1853/28181

24. Bryson, Latoya G. Monomer recovery from nylon carpets via reactive extrusion.

Degree: PhD, Chemical and Biomolecular Engineering, 2008, Georgia Tech

URL: http://hdl.handle.net/1853/22618

► The catalytic depolymerization/pyrolysis of nylon 6 and 66 were investigated with the prospect of helping to curb the amount of carpet landfilled. Thermogravimetric analysis was… (more)

Subjects/Keywords: Extrusion; Nylon 66; Twin screw extruder; TGA; DSC; DTA; DTG; Extruder; Kinetics; Depolymerization; Nylon 6; Monomers; Carpets; Nylon – Deterioration; Recycling (Waste, etc.)

10 more images…

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Bryson, L. G. (2008). Monomer recovery from nylon carpets via reactive extrusion. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/22618

Chicago Manual of Style (16^th Edition):

Bryson, Latoya G. “Monomer recovery from nylon carpets via reactive extrusion.” 2008. Doctoral Dissertation, Georgia Tech. Accessed April 11, 2021. http://hdl.handle.net/1853/22618.

MLA Handbook (7^th Edition):

Bryson, Latoya G. “Monomer recovery from nylon carpets via reactive extrusion.” 2008. Web. 11 Apr 2021.

Vancouver:

Bryson LG. Monomer recovery from nylon carpets via reactive extrusion. [Internet] [Doctoral dissertation]. Georgia Tech; 2008. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/1853/22618.

Council of Science Editors:

Bryson LG. Monomer recovery from nylon carpets via reactive extrusion. [Doctoral Dissertation]. Georgia Tech; 2008. Available from: http://hdl.handle.net/1853/22618

Georgia Tech

25. Wei, Jing. Systematic Design of Bulk Recycling Systems under Uncertainty.

Degree: PhD, Chemical Engineering, 2004, Georgia Tech

URL: http://hdl.handle.net/1853/4978

► The fast growing waste stream of electronic and other complex consumer products is making the bulk recycling problem an important environmental protection issue. These products… (more)

▼ The fast growing waste stream of electronic and other complex consumer products is making the bulk recycling problem an important environmental protection issue. These products must be recycled because they contain hazardous materials such as lead and mercury. The focus of this thesis is the development of systematic methods for designing systems to recover mixed plastics from electronic products such as computers and televisions. Bulk recycling systems are similar to other chemical engineering process systems. Therefore they can be synthesized and designed using some existing techniques that have been applied to distillation and reaction systems. However, the existence of various uncertainties from different sources, such as the variation of component fractions and product prices, makes it crucial to design a flexible and sustainable system, and is also a major challenge in this research. Another challenge is that plastics can be separated by different mechanisms based on different properties, but separating a mix of plastics often requires using a combination of different methods because they can have overlapping differentiating properties. Therefore many decisions are to be made including which methods to choose and how to connect them. To address the problem systematically, the design under uncertainty problem was formulated as a stochastic Mixed Integer Nonlinear Program (sMINLP). A Sample Average Approximation (SAA) method wrapped on the Outer Approximation method has been developed in this thesis to solve such problems efficiently. Therefore, large design under uncertainty problems can be solved without intractable computational difficulty. To allow making choices from separation methods by different mechanisms, this research modeled various plastics separation methods taking account of the distribution of particle properties and unified them using a canonical partition curve representation. Finally, an overall design method was proposed in this work to incorporate the design of size reduction units into the separation system. This research is the first formal development of a systematic method in this area to account for uncertainties and interactions between process steps. Advisors/Committee Members: Realff, Matthew J. (Committee Chair), Ammons, Jane (Committee Member), Gallivan, Martha (Committee Member), Lee, Jay (Committee Member), Schork, F Joseph (Committee Member).

Subjects/Keywords: Optimization; Bulk recycling; Design under uncertainty; Sample average approximation; MINLP; Plastics Recycling

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Wei, J. (2004). Systematic Design of Bulk Recycling Systems under Uncertainty. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/4978

Chicago Manual of Style (16^th Edition):

Wei, Jing. “Systematic Design of Bulk Recycling Systems under Uncertainty.” 2004. Doctoral Dissertation, Georgia Tech. Accessed April 11, 2021. http://hdl.handle.net/1853/4978.

MLA Handbook (7^th Edition):

Wei, Jing. “Systematic Design of Bulk Recycling Systems under Uncertainty.” 2004. Web. 11 Apr 2021.

Vancouver:

Wei J. Systematic Design of Bulk Recycling Systems under Uncertainty. [Internet] [Doctoral dissertation]. Georgia Tech; 2004. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/1853/4978.

Council of Science Editors:

Wei J. Systematic Design of Bulk Recycling Systems under Uncertainty. [Doctoral Dissertation]. Georgia Tech; 2004. Available from: http://hdl.handle.net/1853/4978

Georgia Tech

26. Tosukhowong, Thidarat. Dynamic Real-time Optimization and Control of an Integrated Plant.

Degree: PhD, Chemical Engineering, 2006, Georgia Tech

URL: http://hdl.handle.net/1853/14087

► Applications of the existing steady-state plant-wide optimization and the single-scale fast-rate dynamic optimization strategies to an integrated plant with material recycle have been impeded by… (more)

▼ Applications of the existing steady-state plant-wide optimization and the single-scale fast-rate dynamic optimization strategies to an integrated plant with material recycle have been impeded by several factors. While the steady-state optimization formulation is very simple, the very long transient dynamics of an integrated plant have limited the optimizers execution rate to be extremely low, yielding a suboptimal performance. In contrast, performing dynamic plant-wide optimization at the same rate as local controllers requires exorbitant on-line computational load and may increase the sensitivity to high-frequency dynamics that are irrelevant to the plant-level interactions, which are slow-scale in nature. This thesis proposes a novel multi-scale dynamic optimization and control strategy suitable for an integrated plant. The dynamic plant-wide optimizer in this framework executes at a slow rate to track the slow-scale plant-wide interactions and economics, while leaving the local controllers to handle fast changes related to the local units. Moreover, this slow execution rate demands less computational and modeling requirement than the fast-rate optimizer. An important issue of this method is obtaining a suitable dynamic model when first-principles are unavailable. The difficulties in the system identification process are designing proper input signal to excite this ill-conditioned system and handling the lack of slow-scale dynamic data when the plant experiment cannot be conducted for a long time compared to the settling time. This work presents a grey-box modeling method to incorporate steady-state information to improve the model prediction accuracy. A case study of an integrated plant example is presented to address limitations of the nonlinear model predictive control (NMPC) in terms of the on-line computation and its inability to handle stochastic uncertainties. Then, the approximate dynamic programming (ADP) framework is investigated. This method computes an optimal operating policy under uncertainties off-line. Then, the on-line multi-stage optimization can be transformed into a single-stage problem, thus reducing the real-time computational effort drastically. However, the existing ADP framework is not suitable for an integrated plant with high dimensional state and action space. In this study, we combine several techniques with ADP to apply nonlinear optimal control to the integrated plant example and show its efficacy over NMPC. Advisors/Committee Members: Lee, Jay H. (Committee Chair), Ahmed, Shabbir (Committee Member), Gallivan, Martha (Committee Member), Realff, Matthew J. (Committee Member), Schork, F. Joseph (Committee Member).

Subjects/Keywords: Real-time optimization; Integrated plant; Approximate dynamic programming; Multi-scale optimization; Mathematical optimization; Process control; Dynamic programming; Factories

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Tosukhowong, T. (2006). Dynamic Real-time Optimization and Control of an Integrated Plant. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/14087

Chicago Manual of Style (16^th Edition):

Tosukhowong, Thidarat. “Dynamic Real-time Optimization and Control of an Integrated Plant.” 2006. Doctoral Dissertation, Georgia Tech. Accessed April 11, 2021. http://hdl.handle.net/1853/14087.

MLA Handbook (7^th Edition):

Tosukhowong, Thidarat. “Dynamic Real-time Optimization and Control of an Integrated Plant.” 2006. Web. 11 Apr 2021.

Vancouver:

Tosukhowong T. Dynamic Real-time Optimization and Control of an Integrated Plant. [Internet] [Doctoral dissertation]. Georgia Tech; 2006. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/1853/14087.

Council of Science Editors:

Tosukhowong T. Dynamic Real-time Optimization and Control of an Integrated Plant. [Doctoral Dissertation]. Georgia Tech; 2006. Available from: http://hdl.handle.net/1853/14087

Georgia Tech

27. Dubey, Anshul. Search and Analysis of the Sequence Space of a Protein Using Computational Tools.

Degree: PhD, Chemical Engineering, 2006, Georgia Tech

URL: http://hdl.handle.net/1853/14115

► A new approach to the process of Directed Evolution is proposed, which utilizes different machine learning algorithms. Directed Evolution is a process of improving a… (more)

▼ A new approach to the process of Directed Evolution is proposed, which utilizes different machine learning algorithms. Directed Evolution is a process of improving a protein for catalytic purposes by introducing random mutations in its sequence to create variants. Through these mutations, Directed Evolution explores the sequence space, which is defined as all the possible sequences for a given number of amino acids. Each variant sequence is divided into one of two classes, positive or negative, according to their activity or stability. By employing machine learning algorithms for feature selection on the sequence of these variants of the protein, attributes or amino acids in its sequence important for the classification into positive or negative, can be identified. Support Vector Machines (SVMs) were utilized to identify the important individual amino acids for any protein, which have to be preserved to maintain its activity. The results for the case of beta-lactamase show that such residues can be identified with high accuracy while using a small number of variant sequences. Another class of machine learning problems, Boolean Learning, was used to extend this approach to identifying interactions between the different amino acids in a proteins sequence using the variant sequences. It was shown through simulations that such interactions can be identified for any protein with a reasonable number of variant sequences. For experimental verification of this approach, two fluorescent proteins, mRFP and DsRed, were used to generate variants, which were screened for fluorescence. Using Boolean Learning, an interacting pair was identified, which was shown to be important for the fluorescence. It was also shown through experiments and simulations that knowing such pairs can increase the fraction active variants in the library. A Boolean Learning algorithm was also developed for this application, which can learn Boolean functions from data in the presence of classification noise. Advisors/Committee Members: Bommarius, Andreas S. (Committee Co-Chair), Lee, Jay H. (Committee Co-Chair), Realff, Matthew J. (Committee Co-Chair), Borodovsky, Mark (Committee Member), Lutz, Stefan (Committee Member).

Subjects/Keywords: OCAT; Interacting residues of a protein; Important residues of a protein; Boolean learning; Support vector machines; Machine learning; Directed evolution

Record Details Similar Records Cite « Share

❌

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

APA (6^th Edition):

Dubey, A. (2006). Search and Analysis of the Sequence Space of a Protein Using Computational Tools. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/14115

Chicago Manual of Style (16^th Edition):

Dubey, Anshul. “Search and Analysis of the Sequence Space of a Protein Using Computational Tools.” 2006. Doctoral Dissertation, Georgia Tech. Accessed April 11, 2021. http://hdl.handle.net/1853/14115.

MLA Handbook (7^th Edition):

Dubey, Anshul. “Search and Analysis of the Sequence Space of a Protein Using Computational Tools.” 2006. Web. 11 Apr 2021.

Vancouver:

Dubey A. Search and Analysis of the Sequence Space of a Protein Using Computational Tools. [Internet] [Doctoral dissertation]. Georgia Tech; 2006. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/1853/14115.

Council of Science Editors:

Dubey A. Search and Analysis of the Sequence Space of a Protein Using Computational Tools. [Doctoral Dissertation]. Georgia Tech; 2006. Available from: http://hdl.handle.net/1853/14115

		in
And / Or
		in
And / Or
		in
And / Or
		in

Open Access Theses and Dissertations