Abstract Phase transfer catalysis is an important intensified extraction-reaction process and a p... more Abstract Phase transfer catalysis is an important intensified extraction-reaction process and a powerful tool applied in a vast array of chemical synthesis applications. This technique allows for reactions that are generally not feasible through conventional synthesis routes via the introduction of a heterogeneous transfer catalyst that can carry a reactant species across two immiscible phases. These biphasic conditions enable novel synthesis routes, higher yields, and faster reactions, while also facilitating the separation of certain species. The economic viability and successful large-scale implementation of such processes are heavily contingent on the design and modelling of the systems under consideration. Although a few attempts have been made to create case-specific and generic models for phase transfer catalysis, they suffer from the lack of modelling considerations or thermodynamic model parameters. These limitations restrict the solution space to design new phase transfer catalysis-based processes. In the present work, an integrated and multiscale modelling framework is presented to overcome such limitations for liquid-liquid phase transfer catalysis. The proposed framework requires little to no experimental data and employs different tools at different scales of time and space to model nearly any liquid-liquid phase transfer catalytic system. The objective of this work is to apply this framework towards the process of H2S recovery and conversion from an aqueous alkanolamine solution to value-added products as a means to improve process economics and sustainability, particularly in offshore oil and gas platforms. The framework is validated by comparing the preliminary results with known experimental behaviour. The final results are expected to contribute towards further developing a generic, systematic framework for biphasic reaction-separation processes.
31st European Symposium on Computer Aided Process Engineering, 2021
Abstract Coupling of reaction and extraction, along with the ability to significantly increase re... more Abstract Coupling of reaction and extraction, along with the ability to significantly increase reaction yields at milder conditions, makes liquid-liquid phase transfer catalysis an attractive intensified solution for many industrially important processes. Although there has been some work in terms of mechanistic modeling, solvent selection for such processes has remained a largely untouched topic by academia and industry. This work provides a path towards a systematic solvent screening or design framework by providing a quantum-chemistry-based evaluation method to find suitable green solvents for toluene in the process of hydrogen sulfide valorization from natural gas. From a pool of eight candidate alternatives, three are chosen to be suitable substitutes for toluene based on technical, economic, and environmental measures.
Gene delivery is a promising way to treat hereditary diseases and cancer; however, there is littl... more Gene delivery is a promising way to treat hereditary diseases and cancer; however, there is little understanding of DNA:carrier complex mechanical properties, which may be critical for the protection and release of nucleic acids. We applied optical tweezers to directly measure singlemolecule mechanical properties of DNA condensed using 19-mer poly-l-lysine (PLL) or branched histidine-lysine (HK) peptides. Force-extension profiles indicate that both carriers condense DNA actively, showing force plateaus during stretching and relaxation cycles. As the environment such as carrier concentration, pH, and the presence of zinc ions changes, DNA:HK complexes showed dynamically regulated mechanical properties at multiple force levels. The fundamental knowledge from this study can be applied to design a mechanically tailored complex which may enhance transfection efficiency by controlling the stability of the complex temporally and spatially.
Single molecule techniques have provided novel mechanistic insights on biological processes such ... more Single molecule techniques have provided novel mechanistic insights on biological processes such as protein folding, transcription, and motor protein movement. Using single molecule methods, the distribution of individual molecular behavior is directly measured, which cannot be obtained using conventional bulk approaches. In this study, custom-built optical tweezers with sub-pN force resolution were used to probe the dynamic behavior of DNA:cationic carrier complex. Two histidine-lysine (HK) based polymers (H 3 K4b vs H 3 KG4b) were used to compare their condensation behaviors at the single molecular level. The difference between the two HK polymers at the single molecule level may have a significant implication as to why H 3 KG4b shows much higher gene delivery efficiency than H 3 K4b. The optical tweezers were also used to probe the
Abstract Phase transfer catalysis is an important intensified extraction-reaction process and a p... more Abstract Phase transfer catalysis is an important intensified extraction-reaction process and a powerful tool applied in a vast array of chemical synthesis applications. This technique allows for reactions that are generally not feasible through conventional synthesis routes via the introduction of a heterogeneous transfer catalyst that can carry a reactant species across two immiscible phases. These biphasic conditions enable novel synthesis routes, higher yields, and faster reactions, while also facilitating the separation of certain species. The economic viability and successful large-scale implementation of such processes are heavily contingent on the design and modelling of the systems under consideration. Although a few attempts have been made to create case-specific and generic models for phase transfer catalysis, they suffer from the lack of modelling considerations or thermodynamic model parameters. These limitations restrict the solution space to design new phase transfer catalysis-based processes. In the present work, an integrated and multiscale modelling framework is presented to overcome such limitations for liquid-liquid phase transfer catalysis. The proposed framework requires little to no experimental data and employs different tools at different scales of time and space to model nearly any liquid-liquid phase transfer catalytic system. The objective of this work is to apply this framework towards the process of H2S recovery and conversion from an aqueous alkanolamine solution to value-added products as a means to improve process economics and sustainability, particularly in offshore oil and gas platforms. The framework is validated by comparing the preliminary results with known experimental behaviour. The final results are expected to contribute towards further developing a generic, systematic framework for biphasic reaction-separation processes.
31st European Symposium on Computer Aided Process Engineering, 2021
Abstract Coupling of reaction and extraction, along with the ability to significantly increase re... more Abstract Coupling of reaction and extraction, along with the ability to significantly increase reaction yields at milder conditions, makes liquid-liquid phase transfer catalysis an attractive intensified solution for many industrially important processes. Although there has been some work in terms of mechanistic modeling, solvent selection for such processes has remained a largely untouched topic by academia and industry. This work provides a path towards a systematic solvent screening or design framework by providing a quantum-chemistry-based evaluation method to find suitable green solvents for toluene in the process of hydrogen sulfide valorization from natural gas. From a pool of eight candidate alternatives, three are chosen to be suitable substitutes for toluene based on technical, economic, and environmental measures.
Gene delivery is a promising way to treat hereditary diseases and cancer; however, there is littl... more Gene delivery is a promising way to treat hereditary diseases and cancer; however, there is little understanding of DNA:carrier complex mechanical properties, which may be critical for the protection and release of nucleic acids. We applied optical tweezers to directly measure singlemolecule mechanical properties of DNA condensed using 19-mer poly-l-lysine (PLL) or branched histidine-lysine (HK) peptides. Force-extension profiles indicate that both carriers condense DNA actively, showing force plateaus during stretching and relaxation cycles. As the environment such as carrier concentration, pH, and the presence of zinc ions changes, DNA:HK complexes showed dynamically regulated mechanical properties at multiple force levels. The fundamental knowledge from this study can be applied to design a mechanically tailored complex which may enhance transfection efficiency by controlling the stability of the complex temporally and spatially.
Single molecule techniques have provided novel mechanistic insights on biological processes such ... more Single molecule techniques have provided novel mechanistic insights on biological processes such as protein folding, transcription, and motor protein movement. Using single molecule methods, the distribution of individual molecular behavior is directly measured, which cannot be obtained using conventional bulk approaches. In this study, custom-built optical tweezers with sub-pN force resolution were used to probe the dynamic behavior of DNA:cationic carrier complex. Two histidine-lysine (HK) based polymers (H 3 K4b vs H 3 KG4b) were used to compare their condensation behaviors at the single molecular level. The difference between the two HK polymers at the single molecule level may have a significant implication as to why H 3 KG4b shows much higher gene delivery efficiency than H 3 K4b. The optical tweezers were also used to probe the
Uploads
Papers by Adam P Karcz