High density Mongolian anthracite based porous carbon monoliths for methane storage by adsorption

- Mongolian anthracite based carbon monoliths for methane storage by adsorption.
- Carbon rich anthracite was used to prepare porous carbon monolith with high density.
- Carbon monolith prepared with structurally and energetically heterogeneous surface.
- Methane storage capacity of 162 V/V achieved at 293 K and 3.5 MPa.

Carbon monoliths for methane adsorption were prepared from Mongolian anthracite based activated carbons using carboxy-methyl cellulose as a binder under different molding pressures. Nitrogen adsorption/desorption studies were carried out to obtain the specific surface area, pore volume, pore size distribution and adsorption energy distributions of the monoliths. Methane adsorption experiments on the monoliths were conducted at isothermal condition and at pressures up to around 3.5 MPa in a volumetric adsorption apparatus. As expected, adsorption results indicated that the gravimetric methane capacities of the carbon monoliths increase with increasing surface area. On the other hand, the maximum volumetric uptake of methane was observed as 162 V/V at 293 K and 3.5 MPa on a sample, PMAC1/2-3-65, which has low specific surface area and high packing density comparing with other monoliths. This result implies that the specific surface area of adsorption media is not always a major factor in storing of gases such as methane.