Date of Defense
27-11-2024 11:00 AM
Location
F3 – 021
Document Type
Thesis Defense
Degree Name
Master of Science in Chemical Engineering (MSChE)
College
College of Engineering
Department
Chemical and Petroleum Engineering
First Advisor
Prof. Sulaiman Al-Zuhair
Abstract
The emissions of greenhouse gases to the atmosphere cause a climate change that has devastating impacts. Therefore, reaching the net zero goal, which is the balance between the amount of greenhouse gas emitted to the atmosphere and that removed from it, is critical for the future of our planet unless the net-zero goal is achieved soon, the impacts of climate change will continue to worsen, with severe consequences for ecosystems, human health, and global security. Achieving this goal requires a fundamental shift in the way we produce and consume energy, including the rapid transition to renewable energy sources with improvements in energy efficiency. However, full transformation into renewable energy is a challenging task that requires significant time, effort, and resources. Until this full transformation is reached, if ever, carbon capture will continue to play a key role in achieving the net-zero goal. Post-combustion capture of CO2 is the most suitable technology to enable the reduction of emissions from hard-to-abate sectors, such as heavy industries and transportation. However, the conventional CO2 capture technologies, which mainly depend on the amine-based chemical absorption, face several challenges that need to be overcome. These challenges are mainly the high energy needed for solvent regeneration, rendering the process energy intensive and expensive, solvent corrosivity, requiring frequent maintenance, and leading to higher operating costs, and solvent decomposition, resulting in a loss in efficiency. To overcome these challenges, novel nano-biocatalysts have been tested in this work for the development of nano-fluids that can replace the conventional amine solvents for CO2 capture. The aim was to develop environmentally friendly and cost-effective nano-biocatalysts that allow combining the enhancement of CO2 uptake of nanofluids with the catalytic effect of the Carbonic Anhydrase (CA) enzyme. The synergetic effect of the combination of biotechnology and nanotechnology is expected to enhance the overall performance, compared to that of each technology alone. Enzyme immobilization allows easy repeated reuse, which is not possible using the enzyme in free form. Using nano-particles as immobilization support reduces the mass transfer limitations, commonly encountered with conventional porous supports. Selecting nanoparticles that have adsorption capacity further increases the effectiveness of the process. In this study, four nano-biocatalysts were synthesized by immobilizing bovine carbonic anhydrase onto metal-organic framework (ZIF-8), Iron oxide (Fe2O3), Graphene, and Graphene Oxide (GO) nanoparticles. The nanoparticle and the developed nano-biocatalysts, before and after the reaction, were characterized for their morphology, infrared spectrum, pore size surface area, and hydrophobicity. The results proved the successful adsorption of the enzyme and the stability of the developed nano-biocatalysts. The performance of the developed nano-biocatalysts on CO2 flux has been investigated at different temperatures, dosing, and CO2 pressures.GO nanoparticles showed the best result of CO2 flux with a 92.7 % enhancement of flux compared to that of pure water. By CA immobilization, the CO2 flux enhanced further over that of the free nanoparticles by 32, 21, 37, and 42 % for CA@ZIF-8, CA@Fe2O3, CA@graphene, and CA@GO, respectively. Besides showing the best performance, CA@graphene and CA@GO showed very high reusability, with their activity remained almost unchanged for up to 5 cycles. To further understand the behavior, diffusion-reaction kinetics of CA@GO, the nano-biocatalyst with the best performance, has been analyzed. The present results prove that the developed nano-biocatalysts possess great potential for industrial-scale environmentally friendly and cost-effective CO2 sequestration. The work presented here represents a significant advancement in the field of biotechnology and nanotechnology by demonstrating the synergetic effect of combining these two fields through the use of nano-biocatalysts. This is the first time that such nano-biocatalysts have been tested in the manner presented in this work, making it a novel contribution to the scientific community. In addition, the development of a mathematical kinetics model that considers simultaneous diffusion and reaction provides a more comprehensive understanding of the process. Overall, this work offers a unique and innovative approach to addressing complex biotechnological challenges and opens up exciting avenues for further research in this area.
Included in
DEVELOPMENT OF NOVEL NANOBIOCATALYSTS FOR ENHANCING CARBON DIOXIDE CAPTURE
F3 – 021
The emissions of greenhouse gases to the atmosphere cause a climate change that has devastating impacts. Therefore, reaching the net zero goal, which is the balance between the amount of greenhouse gas emitted to the atmosphere and that removed from it, is critical for the future of our planet unless the net-zero goal is achieved soon, the impacts of climate change will continue to worsen, with severe consequences for ecosystems, human health, and global security. Achieving this goal requires a fundamental shift in the way we produce and consume energy, including the rapid transition to renewable energy sources with improvements in energy efficiency. However, full transformation into renewable energy is a challenging task that requires significant time, effort, and resources. Until this full transformation is reached, if ever, carbon capture will continue to play a key role in achieving the net-zero goal. Post-combustion capture of CO2 is the most suitable technology to enable the reduction of emissions from hard-to-abate sectors, such as heavy industries and transportation. However, the conventional CO2 capture technologies, which mainly depend on the amine-based chemical absorption, face several challenges that need to be overcome. These challenges are mainly the high energy needed for solvent regeneration, rendering the process energy intensive and expensive, solvent corrosivity, requiring frequent maintenance, and leading to higher operating costs, and solvent decomposition, resulting in a loss in efficiency. To overcome these challenges, novel nano-biocatalysts have been tested in this work for the development of nano-fluids that can replace the conventional amine solvents for CO2 capture. The aim was to develop environmentally friendly and cost-effective nano-biocatalysts that allow combining the enhancement of CO2 uptake of nanofluids with the catalytic effect of the Carbonic Anhydrase (CA) enzyme. The synergetic effect of the combination of biotechnology and nanotechnology is expected to enhance the overall performance, compared to that of each technology alone. Enzyme immobilization allows easy repeated reuse, which is not possible using the enzyme in free form. Using nano-particles as immobilization support reduces the mass transfer limitations, commonly encountered with conventional porous supports. Selecting nanoparticles that have adsorption capacity further increases the effectiveness of the process. In this study, four nano-biocatalysts were synthesized by immobilizing bovine carbonic anhydrase onto metal-organic framework (ZIF-8), Iron oxide (Fe2O3), Graphene, and Graphene Oxide (GO) nanoparticles. The nanoparticle and the developed nano-biocatalysts, before and after the reaction, were characterized for their morphology, infrared spectrum, pore size surface area, and hydrophobicity. The results proved the successful adsorption of the enzyme and the stability of the developed nano-biocatalysts. The performance of the developed nano-biocatalysts on CO2 flux has been investigated at different temperatures, dosing, and CO2 pressures.GO nanoparticles showed the best result of CO2 flux with a 92.7 % enhancement of flux compared to that of pure water. By CA immobilization, the CO2 flux enhanced further over that of the free nanoparticles by 32, 21, 37, and 42 % for CA@ZIF-8, CA@Fe2O3, CA@graphene, and CA@GO, respectively. Besides showing the best performance, CA@graphene and CA@GO showed very high reusability, with their activity remained almost unchanged for up to 5 cycles. To further understand the behavior, diffusion-reaction kinetics of CA@GO, the nano-biocatalyst with the best performance, has been analyzed. The present results prove that the developed nano-biocatalysts possess great potential for industrial-scale environmentally friendly and cost-effective CO2 sequestration. The work presented here represents a significant advancement in the field of biotechnology and nanotechnology by demonstrating the synergetic effect of combining these two fields through the use of nano-biocatalysts. This is the first time that such nano-biocatalysts have been tested in the manner presented in this work, making it a novel contribution to the scientific community. In addition, the development of a mathematical kinetics model that considers simultaneous diffusion and reaction provides a more comprehensive understanding of the process. Overall, this work offers a unique and innovative approach to addressing complex biotechnological challenges and opens up exciting avenues for further research in this area.