The liquefaction of crop residues in the presence of ethylene glycol, ethylene carbonate, or polyethylene glycol using sulfuric acid as a catalyst was studied. For all experiments, the liquefaction was conducted at 160 ° C and atmospheric pressure. The mass ratio of feedstock to liquefaction solvents used in all the experiments was 30:100. The results show that the acid catalyzed liquefaction process fit a pseudo-first-order kinetics model. Liquefaction yields of 80, 74, and 60% were obtained in 60 minutes of reaction when corn stover was liquefied with ethylene glycol, a mixture of polyethylene glycol and glycerol (9:1, w/w), and ethylene carbonate, respectively. When ethylene carbonate was used as solvent, the liquefaction yields of rice straw and wheat straw were 67% and 73%, respectively, which is lower than that of corn stover (80%). When a mixture of ethylene carbonate and ethylene glycol (8:2, w/w) was used as solvent, the liquefaction yields for corn stover, rice straw and wheat straw were 78, 68, and 70%, respectively.
Acetic Acid Catalyzed Steam Explosion for Improving the Sugar Recovery of Wheat Straw
