Novel asphalt-based carbon adsorbents with super-high adsorption capacity and excellent selectivity for separation for light hydrocarbons

Abstract Separation and recovery of light hydrocarbons (C2-C3) from gaseous mixtures (C 1 -C 3 ) such as natural gas is of importance for the petroleum industry, and is profitable for natural gas producers if it can be done at normal temperature. In this work, novel asphalt-based activated carbons (A-ACs) were prepared by using asphalt as carbon source for separation of light hydrocarbons. The resultant A-ACs were characterized, and C 3 H 8 , C 2 H 6 and CH 4 adsorption isotherms of A-ACs were measured. Besides, their dynamic separation performance were investigated by fixed bed experiments. The resulting A-ACs exhibited a superior C 3 H 8 and C 2 H 6 adsorption capacity of 11.76 and 6.59 mmol/g at 298 K and 100 kPa, respectively and their BET surface area reached as high as 3131 m 2 /g; The IAST-predicted C 2 H 6 /CH 4 and C 3 H 8 /CH 4 selectivity of the sample A-AC-4 reached as high as 15.1 and 88.8 at 298 K and 100 kPa, respectively, which is superior to many MOFs; C 3 H 8 /C 2 H 6 /CH 4 mixtures can be well separated in the fixed bed of A-ACs at room temperature due to the significant differences between affinities of light hydrocarbons with A-ACs. A-ACs are very promising for separation of the light hydrocarbons.