Experimental Study on Partial Oxidation Reforming of Pyrolysis Tar over Sewage Sludge Char

In the study, pine pyrolysis gases containing rich tar was passed through the bed of sewage sludge char prepared at high temperature to explore the partial oxidation reforming characteristics of pyrolysis tar. Under the varying conditions of equivalence ratio (ER), residence times of 1.25, 2.5, and 3.75 s in the char bed, and reforming temperatures of 700, 800, and 900 °C, we investigated the variations of gas composition, tar conversion ratio, and components in reforming products. After the gases containing rich tar were reformed over the high-temperature char bed, the tar conversion ratio reached 95%. The suitable ER for the reforming process was about 0.05 and allowed the highest contents of H2 and CO and a tar conversion ratio of 98.34%. The increase in the reforming temperature increased the percentages of H2 and CO in syngas to some degree and significantly decreased the tar concentration in syngas. At 900 °C, the tar conversion ratio reached 99.19%, and the obtained tar mainly belonged to 2–3 ring ...