Article ID: 10we146
Tar and char are by-products in supercritical water gasification of biomass and reduce the carbon gasification efficiency of the process. 5-HMF (5-hydroxymethylfurfural), a well-known dehydration product of glucose, is suspected to be a chief intermediate in the polymerization pathway to form tar and char. In this paper, mixtures of glucose and 5-HMF were used as a feedstock. 0.01-0.05 M of 5-HMF was added into 1.5 wt% (0.083 M) of glucose. The reaction took place under subcritical condition (i.e., 350ºC and 25 MPa). The gas and char formation rate was observed and compared with that of pure glucose (Chuntanapum and Matsumura, 2010). Unexpectedly, the experimental results show no significant change in gas and char yields, despite an up to 5 times increase in 5-HMF concentration. An n-th order kinetic model was developed to describe the gasification and polymerization pathways of glucose under subcritical condition. Main intermediates for gas and char formation still remain as TOC (lumped liquid product).
