Hydrothermal co-liquefaction of rice straw and waste cooking-oil model compound for bio-crude production

This study aims to investigate the hydrothermal co-liquefaction of rice straw (RS) and waste cooking-oil model compound (WCOM) under sub-critical conditions for the optimum bio-crude yield and conversion. Effects of temperature, catalyst (K2CO3), residence time and mass ratios of RS to WCOM on products’ distribution were examined and the reaction mechanism for co-liquefaction of RS and WCOM was also explored. The highest bio-crude yield (88.77%) was obtained when mass ratio of RS to WCOM was 1:3 at 300 ℃, 10 min and in absence of K2CO3. When the mass ratio was 3:1, 1:1 and 1:3, the synergistic effect approached 14.38%, 11.38% and 12.84%, respectively. WCOM could improve the overall conversion rate of RS during co-liquefaction. GC-MS analysis suggested that the bio-crude contained large amounts of fatty acids and smaller amounts of phenols and ketone aldehydes. Co-liquefaction was found effective to improve the qualitative and quantitate features of products from biomass.