Browsing by Subject "Carbon dioxide removal"
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Item Effect of network structure modifications on the light gas transport properties of cross-linked poly(ethylene oxide) membranes(2009-05) Kusuma, Victor Armanda; Freeman, B. D. (Benny D.); Yacamán, M. JoséCross-linked poly(ethylene oxide) (XLPEO) based on poly(ethylene glycol) diacrylate (PEGDA) is an amorphous rubbery material with potential applications for carbon dioxide removal from mixtures with light gases such as methane, hydrogen, oxygen and nitrogen. Changing the polymer network structure of XLPEO through copolymerization has previously been shown to influence gas transport properties, which correlated with fractional free volume according to the Cohen-Turnbull model. This project explores strategic modifications of the cross-linked polymer structure and their effect on the chemical, physical and gas transport properties with an aim to develop rational, molecular-based design rules for tailoring separation performance. Experimental results from calorimetric and dynamic thermal analysis studies are presented, along with pure gas permeability and solubility obtained at 35°C. Incorporation of dangling side chains by copolymerization of PEGDA with methoxy-terminated poly(ethylene glycol) methyl ether acrylate, n=8 (PEGMEA) was previously shown to be effective in increasing fractional free volume of XLPEO through the opening of local free volume elements, which in turn increased CO₂ permeability. Through a comparative study ofshort chain analogs to these co-monomers, incorporation of an ethoxy-terminated co-monomer was shown to be more effective than a comparable methoxy-terminated co-monomer in increasing gas permeability. For instance, copolymerization of PEGDA with 71 wt% ethoxy-terminated diethylene glycol ethyl ether acrylate increased CO₂ permeability from 110 barrer to 320 barrer. Gas permeability increase was not observed when hydroxy or phenoxy-terminated pendants were introduced, which was attributed to reduction in chain mobility due to increased inter-chain chemical interactions or steric restrictions, respectively. Based on these results, incorporation of a co-monomer containing a bulky non-polar terminal group, tris-(trimethylsiloxy)silyl, was examined in order to further increase gas permeability. Addition of 80 wt% TRIS-A co-monomer increased CO₂ permeability of cross-linked PEGDA to 800 barrer. However, the resulting changes in chemical character of the copolymer reduced CO₂/light gas selectivity, even as gas permeability increased. The effect of incorporating a bulky, stiff functional group in the cross-linker chain was studied using cross-linked bisphenol-A ethoxylate diacrylate, which showed 40% increase in permeability compared to cross-linked PEGDA. This study affirmed the importance of polymer chain interaction, in addition to free volume, in determining the gas transport properties of the polymer.Item Estimating CO₂ storage capacity, injectivity, and storage costs for large-scale CCS deployment & carbon dioxide removal goals(2023-04-21) Rodriguez Calzado, Edna; Hovorka, Susan D. (Susan Davis); Bump, Alexander P.Large-scale deployment (i.e.,, nationwide) of Carbon Capture and Storage (CCS) technology will play a key role in carbon storage removal (CDR) and overall climate mitigation efforts. The economic feasibility of large-scale CCS deployments partly depends on the CO₂ storage costs per project. However, the suitability of regional storage and injectivity per project, particularly for large-scale purposes, is not well understood. This study focuses on two concepts that augments existing studies of storage capacity and cost to assess the opportunities and barriers to CDR. The first concept focuses on identifying all potential areas for CO₂ storage within the sedimentary rocks throughout the U.S. based on a novel concept we call the CO₂ Storage Window. The second concept focuses on improving CO₂ storage costs estimates by considering 1) the number of wells needed to inject at a certain rate, dependent on injectivity of the area and 2) the areal extent of pressure build-up caused by CO₂ injection. This area extent is a novel concept we call pressure space. Understanding the pressure space of a project helps delineate the area of review for a project and the extent of the pore space required for the project. The results of this study include a spatial geodatabase and a series of U.S. cohesive, spatial distribution maps showcasing 1) CO₂ storage potential in areas not explored before, 2) Storage costs per CCS project and storage costs per ton of CO₂, assuming a constant maximum storage capacity of 20 Mt per project over a 20-year timeframe, and 3) Estimated storage costs per ton of CO₂ in areas where storage potential is found but where there is not enough data to calculate capacity nor injectivity