Steam reforming of tar using biomass gasification char in a Pilot-scale gasifier

Abstract

Gasification char is a residual material produced during the biomass gasification process. Considered as industrial waste, it is typically disposed of through incineration or landfilling, thereby incurring significant economic costs. Nonetheless, gasification char is characterized by its high carbon content and surface area making it an economical alternative to common catalysts and catalyst support materials. In this study, char from a pilot-scale downdraft gasifier was used to reform the tar generated from the same gasifier. Reforming was performed both in the presence and absence of steam. The aim is to convert condensable hydrocarbon derivatives (tars) into non-condensable lower molecular weight products such as H2 and CO. Reforming test conducted with 0.18 kg/h steam for 2 h at 750 °C and char bed weighing 600 g resulted in a reduction of tar concentration from 2407 mg/Nm3 to 20 mg/Nm3. The same test conditions were also responsible for an increase in H2 production from 15 to 26 vol%. The combined effect of steam and char bed suggests that both upgrading the producer gas as well as cleaning it can be made possible in a single process.