抄録
The purification of biomass -derived syngas via tar and methane abatement by catalytic cracking over Ni catalysts using benzene, toluene and naphthalene as model compounds was investigated. The effects of temperature and steam to carbon ratio on conversion, and the tendency towards coke formation were explored. Three Ni catalysts were prepared by use of metallic nickel as active phase grafted on dolomite. Five catalysts, three Ni catalysts, dolomite and heavy oil cracking catalyst, were evaluated in a bench-scale reactor at 700°C with an S/C ratio of 4.5. The results indicated that the naphthalene was the most difficult compounds to steam reform; the tendency towards coke formation increased as the increasing molecular weight of the aromatic; heavy oil cracking catalysts had a role in cracking biomass tar, but the conversion was limited; Ni catalyst calcined at 900°C showed the best selectivity to H2 and CH4 (H2 68.3%, H2+CO 92.3%, CH4 2.3%). The ageing test (100h at 700°C) indicated: the total content of H2 and CO was unchanged approximately; the ratio of H2/CO decreased with the reducing of catalyst activity; No sintering was observed on this catalyst by characterization studies after catalytic test.
