Reforming solutions for biomass-derived gasification gas – Experimental results and concept assessment

Abstract

Reforming is a key enabling technology for the production of tar and hydrocarbon free synthesis gas from biomass. In this work, two different reforming concepts, steam and autothermal reforming, were studied for cleaning of biomass-derived gasification gas. Long-term laboratory scale experiments (around 500h) were carried out with two model biomass gasification gas compositions with low and medium hydrocarbon loads. The experiments were made using nickel and precious metal catalysts at atmospheric pressure and at temperatures around 900–950°C. The deactivation of the catalysts was followed. Gas with low hydrocarbon content could be steam reformed with nickel and precious metal catalyst. Both autothermal and steam reforming modes were studied for gas with medium hydrocarbon content. In steam reforming mode, the catalysts deactivated more than in autothermal mode. Based on the experiments H2O/CREF molar ratio above 4 and O/CREF molar ratio above 8 are recommended. A concept assessment was carried out to examine plant level impacts of the reforming approaches to synthesis gas production. The results showed that the choice of reforming concept has only limited impact to the overall efficiency of synthetic biofuel production.