Comparison of steam reforming and partial oxidation of biomass pyrolysis tars over activated carbon derived from waste tire

Abstract

The main objective of this work was to analyze catalytic tar destruction in order to compare the performance of two thermochemical processes, partial oxidation and steam reforming. Activated carbon, derived from char obtained in fast pyrolysis of waste tires, was used as a catalyst. The efficiency of this catalyst was analyzed with respect to its ability to decompose tar-forming hydrocarbons at high temperatures, and the optimal conditions of the process were determined.Results of catalytic steam reforming and partial oxidation of real tars from biomass pyrolysis are presented in this article. Tar destruction was performed in a fixed bed reactor at temperatures from 700°C to 900°C, with the steam-to-carbon ratio (H2O/C) from 0 to 1, air equivalence ratio (ER) from 0 to 0.5 at a constant space velocity and the initial concentration of tars 21.1±1.89g/m3. The thermal destruction of tars was found to be most intensive in terms of both tar destruction and hydrogen gas production when using steam reforming at 900°C and H2O/C=1. Under these conditions, an almost complete conversion of tars was achieved, with benzene as the only remainder at a concentration of 0.019g/m3.