Catalytic reforming of tar for enhancing hydrogen production from gasification of hazardous medical waste

Steam-oxygen gasification process has recently had significant successes in converting hazardous medical waste (HMW) into syngas, but it still contains larger amounts of tar than recommended for industrial use, requiring its removal. In this context, this work aims to upgrade syngas derived from HMW gasification using a catalytic reforming process to eliminate tar and increase its hydrogen (H2) content. The experiments were performed on waste surgical masks (as the most common type of HMW) using an integrated conversion system consisting of an updraft gasifier connected in series to a catalytic reforming reactor. A gasifier was used to convert to H2-rich syngas at 900 °C with tar content of 79.23 g/m3 in a steam-oxygen atmosphere with an equivalence air ratio = 0.19 and steam to carbon molar ratio = 1. Then, the tar-laden syngas derived from the gasifier was passed directly to the reforming reactor to carry out the upgrading process using different types of catalysts. The results showed that ZSM-5 and Y-Type catalysis had lower H2 production performance up to 45 vol% and higher tar content in the ranges of 43.6–58.5 g/m3. While Ni/γAl2O3, KATALCO™ 57-4GQ, and Ni/Mg-porous clay heterostructure (PCH) catalysts had a higher H2 production up to 59 vol%. Beside their superior ability to completely eliminate tar content. Accordingly, steam oxygen gasification with catalytic reforming process on Ni/γAl2O3, KATALCO™ 57-4GQ and Ni/Mg-PCH catalysts is highly recommended to process HMW into H2-rich syngas free of tar content.