Molecular Dynamics Evaluation of Removal of Acid Gases from SNG by Ionic Liquid

Abstract

A process for removing acid gas from synthetic natural gas based on ionic liquids (ILs) at room temperature is proposed. The structural properties, such as the radial and special distribution functions, and the dynamic properties, such as the self-diffusivity, are computed by molecular dynamics simulation methods. The microscopic characteristics are related to the macroscopic properties. The effects of different alkyl chain lengths and anionic ILs on the absorption process are studied. The ILs are proven to have good adsorption effects on acid gases, and the optimum IL, namely, [bmim]­[Tf2N], is determined. The structure–property relationships between the ILs and the dissolution diffusion are the basis for designing novel ILs. The design process is simulated by Aspen Plus. The results show that the process has good removal effects and that three key stream concentrations are increased compared with those based on a traditional solvent process. The capture rate of CO2 is 97.6%, the removal rate of H2S is 94.2%, and the CH4 concentration is 98.0%. The sensitivity analysis provides a decision-making basis for designers. Each index of product gas meets the requirements of GB 17820-2018, which enables these gases to be used in remote heating and power applications through the storage and transportation of the existing natural gas infrastructure.

Molecular Insights into SO2 Absorption by [EMIM][Cl]-Based Deep Eutectic Solvents

“…To investigate the interaction between DESs and SO 2 molecules, the initial structures of the molecules were constructed by Gaussview . The geometry of the molecules was optimized using Gaussian16 with B3LYP theory and the basis set level of 6-31G*. , Figure shows the molecular structure optimization basis for this study. Based on the optimization of the molecular structure and energy, the σ-profile for each molecular structure was obtained using COSMOthermX software .…”

Thermodynamic and molecular insights into natural gas dehydration using choline chloride‐based deep eutectic solvents

“…Gaussian 09 software package with the DFT-D3 dispersion corrections to obtain the geometric configuration at the lowest energy state. [39][40][41] All the geometries were preoptimized at B3LYP/6-31G (d, p) theoretical level, and then fully optimized at B3LYP/6-311+G (2d, 2p) theoretical level. 42 The frequency calculation was also performed to confirm the true minimum.…”

“…The water absorption mechanism was explored to provide theoretical guidance for improving the NG dehydration performance. A series of complexes of ChCl, Urea, EG, TEG, H 2 O, and CH 4 were optimized using Gaussian 09 software package with the DFT‐D3 dispersion corrections to obtain the geometric configuration at the lowest energy state 39–41 . All the geometries were preoptimized at B3LYP/6‐31G (d, p) theoretical level, and then fully optimized at B3LYP/6‐311+G (2d, 2p) theoretical level 42 .…”

Deep eutectic solvents for efficient capture of cyclohexane in volatile organic compounds: Thermodynamic and molecular mechanism

“…The intermolecular interaction was calculated by quantum chemistry using the Gaussian 09 software package. [50][51][52] All the geometries were optimized by Gaussian 09 with the DFT-D3 dispersion corrections. 53 All the geometries were pre-optimized at the B3LYP / 6-31G (d, p) theoretical level, and then fully optimized at the B3LYP/6-311 + G (2d, 2p) theoretical level.…”

“…The absorption mechanism was explored here to provide theoretical guidance for improving the cyclohexane absorption performance. The intermolecular interaction was calculated by quantum chemistry using the Gaussian 09 software package 50–52 . All the geometries were optimized by Gaussian 09 with the DFT‐D3 dispersion corrections 53 .…”