Activated carbon derived from waste coffee grounds for stable methane storage

作者：Kemp K Christian^*; Baek Seung Bin; Lee Wang Geun; Meyyappan M; Kim Kwang S

来源：Nanotechnology, 2015, 26(38): 385602.

DOI：10.1088/0957-4484/26/38/385602

• adsorption
• activated carbon
• methane storage
• energy storage
• mechanism
• hydrogen storage

An activated carbon material derived from waste coffee grounds is shown to be an effective and stable medium for methane storage. The sample activated at 900 degrees C displays a surface area of 1040.3 m(2) g(-1) and a micropore volume of 0.574 cm(3) g(-1) and exhibits a stable CH4 adsorption capacity of similar to 4.2 mmol g(-1) at 3.0 MPa and a temperature range of 298 +/- 10 K. The same material exhibits an impressive hydrogen storage capacity of 1.75 wt% as well at 77 K and 100 kPa. Here, we also propose a mechanism for the formation of activated carbon from spent coffee grounds. At low temperatures, the material has two distinct types with low and high surface areas; however, activation at elevated temperatures drives off the low surface area carbon, leaving behind the porous high surface area activated carbon.