Synthesis of hybrid nano-adsorbent for separation of hydrogen from methane

Deposition of carbon nanostructures on the active carbon made of walnut shell, which was chemically activated by KOH, has been studied. To this end, the nano-fibre, single- and multi-walled carbon nano-tubes have been deposited on the active carbon made of walnut shell. After physical activation by carbon dioxide, methane and hydrogen adsorption tests were performed on the samples. The results show that deposition of carbon nano-fibre on the active carbon can increase its methane adsorption capacity up to 17.92% without affecting its hydrogen adsorption capacity. This fact increases the performance of the adsorbent in the separation of hydrogen from methane. Experiments show that the carbon adsorbent hybridised by carbon nano-fibre can separate hydrogen and methane from a mixture containing equal compositions of these two components, to the extent that the outlet flow contains 99.99% pure hydrogen. It must be noted that, the commercial adsorbent used in the present PSA columns produces 73.80% pure hydrogen in the similar condition.

► The new method for nano-hybrid adsorbent was presented. ► Activated carbon is prepared by a cheap material consist of walnut shell. ► The prepared activated carbon can separate CH4/H2 mixture more efficient than CMSH2.