Engineering topics
Publications and source records attributed to Hopkinson, David.
Presented by NETL at 2019 Carbon Capture, Utilization, Storage, and Oil and Gas Technologies Integrated Review Meeting, 8/19
Presented by NETL at 2019 Carbon Capture, Utilization, Storage, and Oil and Gas Technologies Integrated Review Meeting, 8/19
Presented by NETL at 2019 Carbon Capture, Utilization, Storage, and Oil and Gas Technologies Integrated Review Meeting, 8/19
In this work, we introduce novel chemical sorbents based on polymers with intrinsic microporosity (PIMs). For the first time, alkylamines were incorporated in PIMs through an acid–base interaction to create a chemisorbent. The amine-appended PIMs not only showed a nearly four-fold enhancement in CO 2 loading capacity (36.4 cc/g at 0.15 bar and 298 K) and very high CO 2 /N 2 selectivity compared to neat PIM -1 but moreover proved to have stable performance when cycled between adsorption and desorption isotherms under both dry and humid conditions that are typical for postcombustion CO 2 capture.
Ionic liquid gels of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide plasticizing a cross-linked poly(ethylene oxide) are high performance CO 2 separation membranes. Here, the effect of polymer cross-link density on the ionic liquid stability, on the mechanical properties of the resulting films, and on the gas separation properties were studied. Cross-link density was modified by changing the chain length of ethoxylated diacrylate and triacrylate monomers, and by incorporating small amounts of short, multifunctional acrylate monomers. Without the ionic liquid acting as permanent plasticizer, higher cross-link density is associated with higher yield strength but lower strain at break, as expected. In a plasticized network, however, the loss in flexibility is not accompanied by higher yield strength, leaving ion gels made from highly cross-linked network more fragile than those having longer, more flexible chains. In conclusion, lowering cross-link density also allowed more ionic liquids to be incorporated as a phase stable gel and led to better CO 2 separation performance.
Presented by NETL at GRC Nanoporous Materials and Their Applications 08/19
One or more embodiments relate to providing substrate for separating a first gas component from a gaseous mixture, said substrate comprising a benzimidazole-linked polymer. Also provided is a method for synthesizing a substrate for separating a first gas component from a gaseous mixture, the method comprising performing a free condensation reaction between an aryl-o-diamine and an aryl-aldehyde to yield a benzimidazole-linked polymer. Other embodiments related to providing a CO2 separation membrane comprising benzimidazole-linked polymer residing within a matrix.
Presented by NETL at NCCC Project Review Meeting, 05/19
Presented by NETL at The North American Membrane Society 28th Annual Meeting, 05/19
Presented at The North American Membrane Society 28th Annual Meeting Pittsburgh PA 5/15
Presented by NETL at 2019 AIChE Annual Meeting, 11/19
This work describes the preparation of a set of nine new novel hydrophobic PEG-substituted solvents. These solvents include linear, T-shaped, and disubstituted conformations of the PEG grafted with PDMS molecule. The effect of changing both the molecular conformation and length of PEG side arm on the physical properties and CO 2 absorption capacity was studied. These solvents are intended for separation of CO 2 and H 2 in precombustion CO 2 capture and are intended to replace the current-state-of-the-art glycol-based solvents and operate at a higher temperature. In conclusion, the properties of the disubstituted solvents are exceptionally well suited for precombustion CO 2 capture applications because of their hydrophobicity, high CO 2 solubility, low evaporation rate, and lack of foaming.
Polymers of intrinsic microporosity (PIMs) are revolutionary gas separation materials because of their ultra-high permeability, but suffer from low gas pair selectivity (for example CO 2 /N 2 ) and poor durability due to brittleness. In this paper, we present a simple solution to these problems by blending PIM-1 with compatible polymer blend composed of PIM-1 and an ether side chain polyphosphazene (MEEP80), which possesses better mechanical flexibility and higher CO 2 /N 2 selectivity than the native PIM-1 while maintaining high CO 2 permeability. Under mixed gas test conditions, a blend of 25 wt% MEEP80 in PIM-1 has a CO 2 permeability of 2440 barrer and a CO 2 /N 2 selectivity of 39 under mixed gas testing conditions, putting it among the best known polymers for CO 2 /N 2 separation.
Ion gel films were prepared by incorporating eight commercially available ionic liquids in two different cross-linked polymer matrices to evaluate their phase miscibility, gas permeability and ionic conductivity for potential applications as gas separation membranes and solid electrolyte materials. The ionic liquids cations were 1-ethyl-3-methylimidazolium, 1-ethyl-3-methylpyridinium, 1-butyl-1-methylpyrrolidinium, tributylmethylphosphonium, and butyltrimethylammonium with a common anion (bis(trifluoromethylsulfonyl)imide). In addition, ionic liquids with 1-ethyl-3-methylimidazolium cation with acetate, dicyanamide and tetrafluoroborate counterions were evaluated. The two polymers were cross-linked poly(ethylene oxide) and cross-linked poly(ethylene oxide)/siloxane copolymer. Differential scanning calorimetry, X-ray diffractometry and visual observations were performed to evaluate the ion gels’ miscibility, thermal stability and homogeneity. Ionic liquids with the least basic anion (bis(trifluoromethylsulfonyl)imide) and aromatic cations containing acidic proton (e.g. imidazolium and pyridinium) gave the most stable and miscible ion gels. Phase stability was shown to be a function of both ionic liquid content and temperature, with phase separation observed at elevated temperatures. In conclusion, gas permeability testing with carbon dioxide and nitrogen and ionic conductivity measurements confirmed that these ionic liquids increased the gas permeability and ionic conductivity of the polymers.
Presented by NETL at North American Membrane Society, 06/18
Presented by NETL at CO2 Capture Technology Review Meeting, 08/18
1,3-Substituted imidazolium bis(trifluoromethylsulfonyl)imide (Tf 2 N) ionic liquids (ILs) were incorporated at 40 and 60 vol % loading into a cross-linked poly(ethylene oxide) polymer network to create ion gels for carbon dioxide (CO 2 )-selective gas separation membranes. The ILs plasticize the poly(ethylene oxide)-based polymer to increase its gas permeability. Compared to the base polymer, with a CO 2 permeability of 145 barrer and a CO 2 against nitrogen (N 2 ) selectivity of 47, the highest CO 2 permeability achieved was 530 barrer coupled with a CO 2 /N 2 selectivity of 31 by having 60 vol % [1-ethyl-3-methylimidazolium][Tf 2 N]. The extent of gas permeability improvement depends on the cation’s terminal substituent. Substituents that promote additional noncovalent intermolecular interactions, such as hydroxyl, benzyl, and nitrile, can reduce the gas diffusivity by reducing the polymer chain mobility. Here, while n -alkyl, branched alkyl, and oligo(ethylene glycol) substituents can significantly increase the gas permeability, the shortest substituents (such as ethyl) were the most effective because they promote high ionic charge density.
Presented by NETL at Clearwater Clean Coal Conference, 06/18