Coconut shell-based carbon adsorbents for ventilation air methane enrichment

Coconut shell-based carbon adsorbents were prepared and applied to vacuum pressure swing adsorption (VPSA) process for ventilation air methane (VAM) enrichment. The preparation procedure consists simply of pulverization of the coconut shell chars, pelletization with phenolic resin as binder, and carbonization of the pellets under N-2 flow. The pyrolysis characteristics of coconut shells, including the composition of gas products at different pyrolysis temperature interval, the porous characteristics, the proximate and ultimate analyses, the surface functional groups, and the grindability of the chars from varied pyrolysis temperature, were systematically investigated. So that the reasonable pyrolysis temperature for coconut shell chars production was determined. The ratio of phenolic resin to char powder was optimized in regarding of the compressive strength, packing density, textural characteristics, and CH4/N-2 separation factor of the carbon adsorbents. The performance of the carbon adsorbent prepared under optimum condition for VAM enrichment by VPSA was examined, and it merits the need for flow-reversal reactor or lean-burn combustion turbine to generate power. (C) 2013 Elsevier Ltd. All rights reserved.