EVALUATION OF ANAEROBICALLY DIGESTED BIOMASS IN CATALYTIC SUPERCRITICAL WATER GASIFICATION FOR BIOFUEL PRODUCTION

Abstract

Digested water hyacinth with waste sludge as inoculum were obtained after anaerobic digestion at 35 and 45°C. High organiccontent of digested biomass were evaluated through gasification at supercritical conditions of water in the absence andpresence of catalysts (KOH, NaOH, LiOH and K2CO3) with 10 wt.% of volatile solid in feed. Supercritical water gasificationof digested biomass was performed in batch reactor system at temperature and pressure ranges of 500–600°C and 35–45MPa, respectively. The highest carbon gasification efficiency, hydrogen and methane yields were reached at 600°C (withsamples digested at 45°C) in the absence of catalyst as 84.6 (g C in gaseous/g C in digestate), 53.0 (mol $H2%$) and 14.2 (mol$CH4%$), respectively. High organic content of digested biomass was converted by supercritical water gasification to methaneand hydrogen rich gas, and aqueous products (aliphatic hydrocarbons, phenol, substituted phenols, N-heterocyclic,substituted N-heterocyclics, and substituted benzene) that can be evaluated as platform chemicals.