Elimination of H2S contained in biogas by metal-supported active carbon adsorbents

Abstract

Metal-supported active carbon adsorbents were applied to remove the small amount of H2S contained in biogas CH4. H2S adsorption experiments using column type-equipment demonstrated that copper-supported active carbon exhibited high H2S adsorption ability. From the practical point of view, the width and the rate of the adsorption layer were estimated using copper-supported active carbons. Assuming that the metal ion was initially coordinated with oxygen atoms in H2O molecules, the energy change in substituting a H2O molecule by a H2S molecule was calculated using a calculation program for the ab initio molecular orbital method (Gaussian 09). The results of these energy calculations suggest that Cu0 and Cu+ species have the highest adsorption affinity with H2S among various metal and metal ions, in agreement with the present experimental results.