Porous carbon screening for benzene sorption

Benzene is one of the aromatic hydrocarbons that are co-absorbed with the acid gases during amine scrubbing and are carried over to the catalytic reactors in the sulfur recovery unit where they crack and deactivate the catalyst. As a solution, adsorption of benzene using porous adsorbents is being considered as a suitable process for removal. The present work considers carbon based porous adsorbents as potential adsorbents and attempts to screen the large pool of adsorbents. Preliminary screening was made using information in open literature and structural characteristics, before the adsorbents were subjected to gas phase benzene adsorption. The pool of porous carbons screened included highly acidic sulfonated carbons, ordered mesoporous carbons (OMCs) and various commercial activated carbons (ACs). Among the pool of porous carbons, mesoporous carbon identified as AC1, was found to possess the highest adsorption capacity for benzene with heat of adsorption capacity of 20–32 KJ/mol. It was found that it is possible to regenerate the benzene adsorption capacity of AC1 and a benzene adsorption capacity of about 14 mmol/g for the mesoporous carbon was found to be far superior to the adsorption capacities reported in literature.