Production of bio-fuel from alcohothermal liquefaction of rice straw over sulfated-graphene oxide

Abstract

The objective of this research is to investigate the parameters for supercritical ethanol liquefaction of rice straw over sulfated graphene oxide. Graphene oxide was synthesized from thermal treatment of humic acid and then treated with different concentration of sulfuric acid using the wet impregnation technique. Results from liquefaction demonstrated that reaction temperature helped support the production of biofuel, but increase the formation of gas due to cracking reaction. An increase in sulfuric acid helped increase the amount of biofuel produced at first. However, as the sulfuric acid concentration increased higher than 6M, biofuel started to decrease because it is turned into gas and char products. Cracking and isomerization reactions are responsible for these products. The amount of catalyst also have an impact on the liquefaction reaction when it was increased from 5% to 10%. However, as the amount of catalyst increased further the liquefaction did not have a significant change in the ability to produce biofuel. The liquefaction reaction was optimized at 320 ºC, 6M sulfuric acid concentration and 10wt% catalyst producing 33.4% biofuel.