Hydrogen Production via Reforming of the Aqueous Phase of Bio-Oil over Ni/Olivine Catalysts in a Spouted Bed Reactor

Abstract

Hydrogen produced from renewable energy sources can present significant environmental benefits as a means for clean power generation via fuel cells. The aqueous fraction of bio-oil can be used as a source for hydrogen production, if reformed in the presence of active catalytic materials. Recently, we introduced the concept of the spouted bed reactor for this particular process. The aim of the current work is to further investigate the suitability of the novel reactor. The effect of temperature, H2O/C ratio, space velocity, and heat treatment of support was investigated in the presence of Ni/Olivine catalysts. Runs were conducted with ethylene glycol and acetic acid as representative model compounds of the aqueous phase of bio-oil. The organics converted fully toward gases with high selectivity in hydrogen, while the known problem of coking was notably avoided. Ethylene glycol reforming seems to proceed primarily via decomposition followed by reforming of secondary products. Hydrogen yield during acetic acid reforming is higher under equivalent conditions. Tests using the aqueous phase of bio-oil proved more complicated due to the serious thermal instability of the feed. A new injection-cooling system was developed in order to achieve efficient feeding of bio-oil.