Steam reforming of biomass gasification tar over Ni-based catalyst supported by TiO2-SiO2 composite

Abstract

Gasification is an important option for converting biomass into bio-syngas, but it also produces biomass gasification tar, which lowers the gasification efficiency and threatens the safety of the gasifiers. In this work, the TiO2-SiO2 composite-supported Ni-based catalyst was prepared for tar catalytic steam reforming, and its performance was systematically studied, with benzene being the model compound of tar. The results revealed that adding SiO2 to TiO2 improved the conversion of benzene and increased the yield of H2 in the syngas, which respectively reached 61.48% and 49.89 mmol/gbenzene over the 10Ni/1TiO2-0.30SiO2 catalyst, with promising thermal stability and anti-carbon deposition capacity. Furthermore, the presence of SiO2 increased the catalyst’s specific surface area and lowered the sizes of Ni crystals, thereby promoting the dispersion of active Ni sites. Meanwhile, the modification of SiO2 enhanced the catalyst’s redox ability and decreased its acidity, which suppressed the sintering of the catalyst and restricted the accumulation of carbon deposition, while the physical morphology and chemical graphitization degree of the deposits were slightly influenced. Therefore, the catalytic activity and anti-carbon deposition performance of the TiO2-SiO2 composite-supported catalyst were improved during tar catalytic steam reforming.