Synthesis of novel particle rice-based carbon materials and its excellent CH4/N2 adsorption selectivity for methane enrichment from Low-rank natural gas

Ultramicroporous carbon granules with narrow pore size distribution for efficient CH4 separation from coal‐bed gases

“…Notably, this selectivity is higher than that of many top‐ranking adsorbents, such as ZK‐5 (~4.2), 20 CGUCs (5.4), 45 OMC (3.7), 46 and MIL‐100(Cr) (3.0) 47 . Furthermore, the high CH 4 /N 2 selectivity and CH 4 adsorption capacity were exhibited simultaneously by granular GOC‐2, as shown in Figure 3d 1,2,17,20,45‐55 . Thus, GOC‐2 sets a benchmark for CH 4 separation and concentration from low‐grade coal‐bed gas.…”

“…Therefore, it is imperative to explore and utilize alternative CH 4 sources besides the traditional fossil fuels 1 . Coal‐bed methane is an unconventional natural gas source that is stored in coal seams and is mainly composed of nitrogen (N 2 ) as well as trace impurities, that is, O 2 , CO 2 , and water vapor 2,3 . The relatively low concentration of CH 4 (<30%) in typical coal‐bed gas necessitates sequential enrichment processes, and because of the wide explosion limit (5%–16%), cautious handling is necessary 4‐6 .…”

Separation and Purification of Hydrocarbons with Porous Materials

“…chose rice as a carbon source for making carbon‐based adsorbents and found that carboxyl groups are the dominant surface groups and responsible for the enhanced IAST CH 4 /N 2 selectivity. [13d] More recently, Lu et al. reported self‐pillared 2D polymer and ultramicroporous carbon plates prepared by a one‐pot multicomponent sequential assembly method.…”

Facile synthesis of ultramicroporous carbon adsorbents with ultra‐high CH4 uptake by in situ ionic activation

“…One potential strategy for accomplishing this goal involves the selective adsorption of dilute CH 4 from a stream of CH 4 /N 2 by porous materials, which would be both economically and operationally feasible, as well as highly energy efficient. In this regard, many adsorptive materials, including metal–organic frameworks (MOFs), zeolites, and carbon‐based adsorbents, have been examined for the separation of CH 4 /N 2 7‐10 . Specifically, MOFs comprise a new generation of porous materials that have recently demonstrated excellent CH 4 adsorption properties; for example, MOF‐177, 11 M 3 (HCOO) 6 (M = Co, Ni), 12 Co 3 (C 4 O 4 ) 2 (OH) 2 , 13 all exhibit high uptake values for CH 4 , or high CH 4 /N 2 selectivity.…”

“…In this regard, many adsorptive materials, including metal-organic frameworks (MOFs), zeolites, and carbon-based adsorbents, have been examined for the separation of CH 4 /N 2 . [7][8][9][10] Specifically, MOFs comprise a new generation of porous materials that have recently demonstrated excellent CH 4 adsorption properties; for example, MOF-177, 11 M 3 (HCOO) 6 (M = Co, Ni), 12 Co 3 (C 4 O 4 ) 2 (OH) 2 , 13 all exhibit high uptake values for CH 4 , or high CH 4 /N 2 selectivity. However, these materials still face significant challenges before they can be considered for real applications, such as demonstrating long-term stability under exposure to these gas streams, decreasing the cost of manufacturing these materials, and synthesizing a material that exhibits both high CH 4 /N 2 selectivity and high CH 4 capacity.…”