Preparation Of Liquid Fuel By Etherification Of Cellulosic Degradation Products

At the present time, China and the world are facing the problem of the shortage of energy. Bioenergy is a kind of energy using biological renewable materials as raw materials. Plant fiber is the world's largest renewable resources, the use of cellulosic to produce bio-energy shows great potential. China has abundant cellulosic resources, including corn cob, bagasse, wheat bran, straw and other cellulose-rich agricultural, forestry waste etc., to produce bio-energy.In this research, ethylization reaction conditions for sucrose, mannitol and glycerol respectively with chloroethane are investigated; and the structure and combustible properties of the ethylized products were analyzed. The ethylization of the degradation products (by dilute suluric acid) from corn cobs, bagasse, and wheat bran was also studied. The main results were as follows:(1) Four factors, including chloroethane and sodium hydroxide addition amount, reaction temperature and time, showed influence on ethylization similar for sucrose, mannitol, and glycerol. For example, the optimal ethylization technology for glycerol was:chloroethane and sodium hydroxide were respectively added at a level of 1.25:1 and 1:1 in a molar ratio with total hydroxyl group of glyceride and reacted at 120℃for 8h. Under this condition, production of ethylized glycerol is 14.61g/10mL glycerol.(2) GC/MS analysis showed that ethylization of sucrose produced the products with different degree of substitution, the product with 6 to 7 hydroxyls substituted was most abundant, accounting for 70.39% of the total; Only 5.26% of the products in which all of the hydroxyls were ethylized. For mannitol, the products with 4 to 5 hydroxyls ethylized accounted for 79.54%; the contents of the ethylized products with 2 and 3 hydroxyls substituted were 62.57% and 31.36% respectively for glycerol.The combustion properties of the products were tested. The results show that the products can be used as liquid fuel.(3) Corn cobs, bagasse, wheat bran were hydrolyzed using 1% sulfuric acid in a ratio of 1:6 (w/v) at 180℃for 30min, the results showed that 47.8%,38.8%,42.8% of the soluble products were respectively released; The majority of degradation products in the hydrolyzates were reducing monosaccharides. Corn cob and wheat bran hydrolyzates contained 75.35% and 97.16% of xylose and arabinose respectively, while that from sugar cane bagasse contained 78.59% of xylose. All of the hydrolyzates had low content of oligosaccharides.(4) Corn cob, bagasse and wheat bran hydrolyzates were hydrogenated using 0.1%(w/w) sodium borohydride for 30min, hydrogenation solution were added sodium hydroxide, tetrabutyl amonium bromide (TBAB) and chloroethane, after reaction, etherification product was obtained. Analysis showed that content of ethylized products from five-carbon sugar alcohols was higher than that from other sugar alcohols. The product with 3 to 5 hydroxyls substituted was most abundant, accounting for 33.91%,52.52%,42.08% in the hydrolyzates from the corn cobs, bagasse and wheat bran respectively; The six-carbon sugar alcohol hydroxyl groups were mostly replaced on the number 3,4 and 5-carbon.The combustion properties of the corn cobs, bagasse and wheat bran'etherification products were tested. The results show that the products can be used as liquid fuel.