Microporous metal organic frameworks (MOFs) are a novel class of materials formed through self-assembly of inorganic and organic structural building units (SBUs). They show great promise for many applications thanks to record-breaking internal surface areas, high porosity as well as a wide variety of possible chemical compositions. Molecular simulation has been instrumental in the study of MOFs to date, and this thesis work aims to validate and expand upon these efforts through two distinct computational MOF investigations. Current separation technologies used for CO2/N2 mixtures, found in the greenhouse gas-emitting flue gas generated by coal-burning power plants, could greatly benefit from the improved cost-effective separation MOF technology offers. MOFs have shown great potential for CO2 capture due to their low heat capacities and high, selective uptake of CO2. To ensure that simulation techniques effectively predict quantitative MOF gas uptakes and selectivities, it is important that the simulation parameters used, such as force fields, are adequate. We show that in all cases explored, the force field in current widespread use for N2 adsorption over-predicts uptake by at least 50% of the experimental uptake in MOFs. We propose a new N2 model, NIMF (Nitrogen in MoFs), that has been parameterized using experimental N2 uptake data in a diverse range of MOFs found in literature. The NIMF force field yields high accuracy N2 uptakes and will allow for accurate simulated uptakes and selectivities in existing and hypothetical MOF materials and will facilitate accurate identification of promising materials for CO2 capture and storage as well as air separation for oxy-fuel combustion. We also present the results of grand canonical and canonical Monte Carlo (GCMC and canonical MC), DFT and molecular dynamics (MD) simulations as well as charge density analyses, on both CO2 and N,N-dimethylformamide adsorbed in Ba2TMA(NO3) and MIL-68(In), two MOFs with non-equivalent inorganic structural building units. We demonstrate the excellent agreement found between our simulation results and the solid-state NMR (SSNMR) experiments carried out by Professor Yining Huang (Western University) on these two MOFs. Molecular simulation enables discoveries which complement SSNMR such as the number, distribution and dynamics of guest binding sites within a MOF. We show that the combination of SSNMR and molecular simulation forms a powerful analytical procedure for characterizing MOFs, and this novel set of microscopic characterization techniques allows for the optimization of new and existing MOFs.

In this thesis computational chemistry has been used to accelerate experimental discovery in the fields of ice recrystallization inhibitors for cryopreservation and ultra-microporous MOFs for carbon dioxide capture and storage. Ice recrystallization is one of the leading contributors to cell damage and death during the freezing process. This occurs when larger ice crystal grains grow at the expense of smaller ones. Naturally occurring biological antifreeze molecules have been discovered but only operate up to -4oC and actually exasperate the problem at temperatures lower than this. Recently, the group of Dr. Robert Ben have been successful in synthesizing small organic molecules which are capable of inhibiting the growth of ice crystals during the freezing process. They have built a library of diverse compounds with varying functionalities and activity. Chemical intuition has been unsuccessful in finding a discernible trend with which to predict activity. Herein we present work where we have utilized a quantitative structure activity relationship (QSAR) model to predict whether a molecule is active or inactive. This was built from a database of 124 structures and was found to have a positive find rate of 82%. Proposed molecules that had yet to be synthesized were predicted to active or inactive using our method and 9/11 structures were indeed active which is strikingly consistent to the 82% find rate. Our efforts to aid in the discovery of these novel molecules will be described here. Metal organic frameworks (MOFs) are a relatively new class of porous materials which have taken the academic community by storm. These three-dimensional crystalline materials are built from a metal node and an organic linker. Depending on the metals and organic linkers used, MOFs can possess a vast range of topologies and properties that can be exploited for specific applications. Ultra-microporous MOFs possess relatively small pores in the range of 3.5 Å to 6 Å in diameter. These MOFs have some structural advantages compared to larger pored MOFs such as molecular sieving, smaller pores which promote strong framework-gas interactions and cooperative effects between guests, and longer shelf-life due to small void volumes and rigid frameworks. Here we present newly synthesized ultra-microporous MOFs based on isonicotnic acid as the organic linker with Ni and Mg as the metal centre. Despite having such small pores, Ni-4PyC exhibits exceptionally high CO2 uptake at high pressures. Furthermore, Mg-4PyC exhibits novel pressure dependent gate-opening behaviour. Computational simulations were employed to investigate the origin of high CO2 uptake, predict high pressure (>10bar) isotherms, quantify CO2 binding site positions and energies, and study uptake-dependent linker dynamics. This work hopes to provide experimentalists with some explanation to these interesting unexplained phenomena and also predict optimal properties for new applications.

Environmental concerns about the effect of greenhouse gases have led governments to regulate industrial CO2 emissions, including through emissions caps, trading and penalties, thus creating economic incentives to reduce CO2 emissions. This research focuses on strategies to reduce CO2 emissions from energy systems in the context of the process industries. In the process industries, energy systems consume fuel to generate steam and power for site process units. Improving energy efficiency can reduce costs of energy generation and use, as well as CO2 emissions. This research develops an integrated design and optimisation methodology for energy systems, allowing effective capture and control of carbon dioxide emissions. The first focus of this study is to develop a systematic approach to evaluate combinatorial strategies for reducing CO2 emissions, based on a techno-economic analysis. A conceptual design procedure with hierarchical decision-making is introduced to combine CO2 emissions reduction strategies, accounting for interactions between site components, including the heat exchanger network and utility system. CO2 emissions reduction options considered in development of this procedure include process integration techniques for improving the energy efficiency of the site and fuel switching. The proposed approach considers trade-offs between the economy of energy retrofit and CO2 emissions penalties. Opportunity for reducing the CO2 penalty is included in the economic evaluation of the combined emissions reduction strategies. A mathematical model for simultaneous optimization of emissions reduction strategies is developed. In addition to emissions reduction strategies, options for trading CO2 allowances are considered in the model. The proposed mathematical method applies Mixed Integer Non Linear Programming (MINLP) optimization, which employs a superstructure of the strategies for CO2 reduction. The proposed mathematical model relates the selected options to their operating and capital costs and to their associated CO2 emissions, allowing the optimizer to search for the optimal combination of emissions reduction strategies. While the reduction in CO2 emissions through process integration techniques is based on the existing configuration of a site and the associated structural limitations, integration of Carbon Capture and Storage (CCS) technologies can provide greater mitigation of CO2 emissions from a site. However, important challenges of implementing CCS in the process industries are the energetic and economic impact of the CCS plant on the integrated site. In the second part of this study, these energy-economic issues are explored. The CCS technologies addressed in this thesis include post- and pre-combustion CO2 capture techniques. Simulation of each capture technique is carried out in process simulation software to characterize the energy performance of the CO2 capture plant. Sensitivity analyses are carried out for key parameters of the CO2 capture plant. The relationship between these key parameters and the energy balance of the capture plant is represented using a simple energy performance model for the CO2 capture plant. This model allows the integration of the CO2 capture plant with the site utility system to be explored. Interactions between the utility system and CO2 capture plant are considered. The site utility system, together with the CO2 capture plant, is optimized for minimum operating cost. The proposed procedures are illustrated by application to a case study of a medium-scale oil refinery. The results illustrate that to reduce CO2 emissions, heat integration, utility system optimization and fuel switching provide more cost-effective solutions than integrating CCS technologies. The mathematical model allows more cost-effective solutions to be identified than using sequential, conceptual methods, but the value of the conceptual method for developing insights is also illustrated. The results demonstrate that, depending on the potential of the site for increasing heat recovery and the type of fuel used on site, solutions that combine energy efficiency and fuel switching can provide up to 40% reduction in site CO2 emissions. Integrating a post-combustion CO2 capture plant with the site utility system can provide up to 90 mol% pure CO2 for sequestration; however, the high capital cost of the capture plant reduces the economic performance of the integrated site. The high heat demand of post-combustion CO2 capture for solvent regeneration increases the fuel consumption of the site and its utility system, which in turn reduces the recovery of CO2. The results reveal that pre-combustion CO2 capture can provide opportunities for heat and power generation to improve the techno-economic performance of the overall integrated site.

abstract: Global warming resulted from greenhouse gases emission has received widespread attention. Meanwhile, it is required to explore renewable and environmentally friendly energy sources due to the severe pollution of the environment caused by fossil fuel combustion. In order to realize a substantial adsorption process to resolve the environmental issues, the development of new adsorbents with improved properties has become the most critical issue. This dissertation presents the work of four individual but related studies on systematic characterization and process simulations of novel adsorbents with superior adsorption properties. A perovskite oxide material, La0.1Sr0.9Co0.9Fe0.1O3-δ (LSCF1991), was investigated first for high-temperature air separation. The oxygen sorption/desorption behavior of LSCF1991 was studied by thermogravimetric analysis (TGA) and fixed-bed breakthrough experiments. A parametric study was performed to design and optimize the operating parameters of the high-temperature air separation process by pressure swing adsorption (PSA). The results have shown great potential for applying LSCF1991 to the high-temperature air separation due to its excellent separation performance and low energy requirement. Research on using nanostructured zeolite NaX (NZ) as adsorbents for CO2 capture was subsequently conducted. The CO2/N2 adsorption characterizations indicated that the NZ samples lead to enhanced adsorption properties compared with the commercial zeolites (MZ). From the two-bed six-step PSA simulation, NZ saved around 30% energy over MZ for CO2 capture and recovery while achieving a higher CO2 purity and productivity. A unique screening method was developed for efficient evaluation of adsorbents for PSA processes. In the case study, 47 novel adsorbents have been screened for coal bed methane (CBM) recovery. The adsorbents went through scoring-based prescreening, PSA simulation, and optimization. The process performance indicators were correlated with the adsorption selectivity and capacities, which provides new insights for predicting the PSA performance. A new medium-temperature oxygen sorbent, YBaCo4O7+δ (YBC114), was investigated as an oxygen pumping material to facilitate solar thermochemical fuel production. The oxygen uptake and release attributes of YBC114 were studied by both TGA and a small-scale evacuation test. The study proved that the particle size has a significant effect on the oxygen pumping behavior of YBC114, especially for the uptake kinetics. / Dissertation/Thesis / Doctoral Dissertation Chemical Engineering 2020

Carbon dioxide is a viable resource, if used as a raw material for bioprocessing. It is abundant and can be collected as a byproduct from industrial processes. Globally, photosynthetic organisms utilize around 6’000 TW (terawatt) of solar energy to fix ca. 800 Gt (gigaton) of CO2 in the planets largest carbon-capture process. Photosynthesis combines light harvesting, charge separation, catalytic water splitting, generation of reduction equivalents (NADH), energy (ATP) production and CO2 fixation into one highly interconnected and regulated process. While this simplicity makes photosynthetic production of commodity interesting, yet photosynthesis suffers from low energy efficiency, which translates in an extensive footprint for solar biofuels production conditions that store < 2% of solar energy. Electron transfer processes form the core of photosynthesis. At moderate light intensity, the electron transport chains reach maximum transfer rates and only work when photons are at appropriate wavelengths, rendering the process susceptible to oxidative damage, which leads to photo-inhibition and loss of efficiency. Based on our fundamental analysis of the specialized tasks in photosynthesis, we aimed to optimize the efficiency of these processes separately, then combine them in an artificial photosynthesis (AP) process that surpasses the low efficiency of natural photosynthesis. Therefore, by combining photovoltaic light harvesting with electrolytic water splitting or CO2 reduction in combination with microbiological conversion of electrochemical products to higher valuable compounds, we developed an electro-microbial carbon capture and conversion setups that capture CO2 into the targeted bioplastic; polyhydroxybutyrate (PHB). Based on the type of the electrochemical products, and the microorganism that either (i) convert products formed by electrochemical reduction of CO2, e.g. formate (using inorganic cathodes), or (ii) use electrochemically produced H2 to reduce CO2 into higher compounds (autotrophy), three AP setups were designed: one-pot, two-pot, and three-pot setups. We evaluated the kinetic (microbial uptake and conversion, electrochemical reduction) and thermodynamics (efficiencies) of the separate processes, and the overall process efficiency of AP compared to photosynthesis. We address the influence of several parameters on efficiencies and time-space yields, e.g. salinity, pH, electrodes, media, partial pressures of H2 and CO2. These data provide a valuable basis to establish a highly efficient and continuous AP process in the future.

Energy use around the world will rise in the coming decades. Renewable energy sources will help meet this demand, but renewable sources suffer from intermittency, uncontrollable power supply, geographic limitations, and other issues. Many of these issues can be mitigated by introducing energy storage technologies. These technologies facilitate load following and can effectively time-shift power. This analysis compares dedicated and synergistic energy storage technologies using energy efficiency as the primary metric. Energy storage will help renewable sources come to the grid, but fossil fuels still dominate energy sources for decades to come in nearly all projections. Carbon capture technologies can significantly reduce the negative environmental impact of these power plants. There are many carbon capture technologies under development. This analysis considers both the innovative and relatively new cryogenic carbon capture™ (CCC) process and more traditional solvent-based systems. The CCC process requires less energy than other leading technologies while simultaneously providing a means of energy storage for the power plant. This analysis shows CCC is effective as a means to capture CO2 from coal-fired power plants, natural-gas-fired power plants, and syngas production plants. Statistical analysis includes two carbon capture technologies and illustrates how uncertainty quantification (UQ) provides error bars for simulations. UQ provides information on data gaps, uncertainties for property models, and distributions for model predictions. In addition, UQ results provide a discrepancy function that can be introduced into the model to provide a better fit to data and better accuracy overall.

This pre-feasibility study was taken out by the co-operation with Zhejiang University, the CEU lab in Zhejiang University is taking researches of the algae based carbon dioxide capture technology, this report mainly aims to evaluate the GHG mitigation effect of this technology and give suggestions.   This study was carried out at Zhejiang University based on the Zhoushan islands waste incineration power plant project, the report presents the initial feasibility study for the algae based carbon capture and utilization technology focus on the carbon footprint and value summary . First the algae based CCU technology was introduced, then by using the life cycle assessment methodology and based on the description of the whole algae based carbon capture utilization process, each process unit was defined, concerning mass balance analysis was made for each unit, according to the mass balance analysis, carbon flow data was obtained for the whole process. In the discussion part, the carbon dioxide capture and avoid amount was analyzed, also the economic value summary for the material input and output was discussed. Concerning general suggestions for the further development and research about the project were given in five sectors: biotechnology, cultivation and harvesting, biomass utilization, substance and energy input, human resource.   The final conclusion is that the algae based carbon capture and utilization technology is not a carbon negative process, but could produce renewable fuels to avoid certain fossil fuels consumption. Lots of technical limitations exist in the study, it needs more work to applied this technology into reality for China. And the profit analysis based on the value summary for the project is optimistic without the consideration of the initial cost. The algae base CCU technology may become a useful alternative for the carbon abatement in China but not the best choice.

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The ultimate goal of this project is to comprehensively investigate induced seismicity potential by studying the behavior of fault shear zones during high pressure CO2 injection for utilization and storage operations. Seismicity induced by fluid injection is one of the major concerns associated with recent energy technologies such as Carbon capture and storage (CCS) projects. CO2 injection increases reservoir pore pressure and decreases the effective stress causing deformation that can degrade the storage integrity by creating new fractures and reactivating faults. The first consequence is that reactivation of faults and fractures create a pathway for upward CO2 migration. The increased seismic activity is the second consequence, which raises the public concern despite the small magnitudes of such earthquakes. Changes in pore fluid pressure within the injection zone can induce low-magnitude seismic events. However, there are multiple involved Thermo-Hydro-Mechanical (THM) processes during and after fault slip that influences pore pressure and fault strength. Flash heating and thermal pressurization are two examples of such processes that can weaken the fault and decrease frictional resistance along the fault. The proposed study aims to use a multi-physics numerical simulation to analyze the fault shear zone mechanics and capture the involved THM processes during CO2 injection. In one study, a coupled THM model is performed to simulate stress and pore pressure changes in the fault and ultimately measuring the maximum induced magnitude. The other study investigates the response of the fault shear zone during CO2 injection with and without considering the thermal pressurization (TP) effect. In the third part, the realistic behavior of friction was studied by using a rate-and-state friction theory to capture the full earthquake rupture sequence. The outcome of the proposed project can significantly increase the efficiency and public acceptance of CCS technology by addressing the major concerns related to the induced seismicity due to CO2 injection.