Atomistic modeling toward high-efficiency carbon capture: A brief survey with a few illustrative examples

Abstract

With the negative environmental implications of the anthropogenic emission of greenhouse gases like CO 2 having been scientifically established, emphasis is being placed on a concerted global effort to prevent such gases from reaching the atmosphere. Especially important are capture efforts at large point emission sources like fossil fuel power generation, natural gas processing, and various industrial plants. Given the importance and scale of such activities, it is a significant priority to optimize the capture process in terms of speed, energy requirements, and cost efficiency. For CO 2 capture, in particular, multiple systems are being pursued both with near-term retrofitting and medium-to long-term designs in mind, including: (1) liquid solvents like amines, carbonates, and ionic liquids (ILs); (2) microporous sorbents like zeolites, activated carbon, and metal-organic frameworks; (3) solid sorbents like metal-oxides and ionic clays; and (4) polymeric and inorganic membrane separators. Each system is unique in its molecularlevel guest-host interactions, chemistry, heats of adsorption/ desorption, and equilibrium thermodynamic and transport properties as a function of loading, temperature, and pressure. This opens up exciting opportunities for molecular modeling in the design and optimization of materials systems. Here, we offer a brief survey of molecular modeling applications in the field of carbon capture, with a few illustrative examples from our own work primarily involving amine solutions and ILs. Important molecular dynamics, Monte Carlo, and correlationsbased work in the literature relevant to CO 2 capture in other systems are also discussed.

High flux high-silica SSZ-13 membrane for CO2separation

“…The H 2 /SF 6 and H 2 /CH 4 ideal permselectivities are higher than 500 and 15, respectively, well above the respective values for the Knudsen selectivity of 8.5 and 2.8. SF 6 can only diffuse through defects in the zeolite lm. Diffusion of adsorbing gases through 8MR zeolites at moderate temperatures is governed by surface diffusion.…”

“…4 Capturing CO 2 is technologically very challenging and it is estimated to account for 50-90% of the total cost in the CCS/CCU chain. 6,7 Drawbacks of this industrial process are the cyclic operation and the high energy penalty. 6,7 Drawbacks of this industrial process are the cyclic operation and the high energy penalty.…”

CO2–C4H10 Mixtures Simulated in Silica Slit Pores: Relation between Structure and Dynamics

“…16 Should CO 2 exhibit higher affinity to the rock formations than hydrocarbons, it could help increase production. Understanding the relation between competitive adsorption and transport of CO 2 and hydrocarbons in rock formations is considered crucial to optimize both CO 2 storage capacity 17 and natural gas production.…”

Computational approaches to understanding reaction outcomes of organic processes in ionic liquids

“…236 The importance of considering the dipole and quadrupole moments of solutes was also highlighted when looking at the solubility of gases in ionic liquids; this area has gained much attention in recent years, mainly focused around capture and storage of greenhouse gases. [240][241][242][243] A classical molecular dynamics study investigated the solubility of a number of different gases in the ionic liquid [Emim][N(SO 2 CF 3 ) 2 ]; they found that both hydrogen sulphide (which has a signicant dipole moment) and carbon dioxide (no dipole moment but with a large quadrupole moment), were highly soluble. In contrast, molecular hydrogen and nitrogen, with no dipole or quadrupole moments, were much less soluble.…”