The rational design of Li-doped nitrogen adsorbents for natural gas purification. Issue 2 (5th January 2021)

• Record Type: Journal Article
• Authors: He, Jialuo; Mousavi, Seyed Hesam; Li, Guoliang; Li, Zhikao; Mokarizadeh, Abdol Hadi; Shang, Jin; May, Eric F.; Li, Gang (Kevin)
• Is Part Of: Physical chemistry chemical physics. Volume 23:Issue 2(2020)
• Page Start: 971
• Page End: 981
• Publication Date: 2021-01-05
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/d0cp04690f
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : Lithium (Li)-doped polycyclic aromatic hydrocarbons showed a high potential for N2 removal from natural gas. Li doping significantly increases the gas adsorption energies resulting in considerable N2 adsorption selectivity. Abstract : Separation of nitrogen (N2 ) and methane (CH4 ) is one of the most challenging and energy-intensive processes in the natural gas industry, due to their close physico-chemical properties. The quest for an effective N2 -selective adsorbent has long been the focus of research; however, the results have been sparse. In this work, a first-principle study has been used to construct and investigate Li-doped polycyclic aromatic hydrocarbons (PAHs) for N2 rejection in natural gas purification. We doped lithium on a series of linear/nonlinear PAHs consisting of two to six benzene rings. The adsorption affinity of the Li-doped organic molecular systems toward N2 and CH4 was evaluated by calculating the interaction energy using density functional theory. From the gas adsorption selectivities for different Li-doped PAHs, Li-doped phenanthrene and chrysene showed the highest N2 over CH4 equilibrium selectivities, with values of 119.7 and 80.8, respectively. It was found that the Li atom enabled the π bond of the aromatic substrate to interfere with the N2 lowest unoccupied molecular orbital, resulting in strong physisorption of N2 . These results indicate the high potential of Li-doped phenanthrene and chrysene for N2 removal from natural gas.