Supercritical Water Liquefaction of Coal and Waste Tires

Effects of Partial Oxidation and the Water-gas Shift Reaction

Abstract

Supercritical water liquefaction of scrap tire rubber and Ishikari coal, separately and in mixtures was investigated to study the possible synergetic effects of coliquefaction between the feedstocks. The effects of partial oxidation on the liquefaction characteristics caused by the water-gas shift reaction in supercritical water were also investigated. Liquefaction was carried out in a tube-bomb reactor at 673K and 25MPa, in the presence and absence of Ni catalyst. The Ni catalyst increased the content of H₂ and decreased the content of CO in the gas product for both separate and mixture liquefaction, indicating that the water-gas shift reaction was increased by the Ni catalyst. Carbon conversion for coal-tire coliquefaction was greater than the average of the separate conversions, especially when using the Ni catalyst.