Chemicals from biomass

Agricultural and forest residues as well as urban waste derived from forest products contain significant amounts of cellulose which could be converted into ethanol, a liquid fuel. To realize this potential it is necessary to hydrolyze the cellulose-bearing materials to sugars. \n \nThe present state of knowledge of the biomass conversion and structure and its hydrolysis was reviewed. A detailed study of the gaseous hydrogen chloride hydrolysis was made to examine the possibility of producing ethanol from biomass with a simple process. Such information using jarrah (Eucalyptus marginata), pine (Pinus radiata), and wheat (Triticum vulgare var. Egret) straw as typical substrates provided worthwile data relating to Australian conditions and led to a better understanding of biomass hydrolysis. Under optimum conditions a sugar yield of 92% of theoretical was achieved from whole biomass without pretreatment. \n \nA model was developed to describe the hydrogen chloride-wood reaction process which consists of three consecutive major steps: (a) precooling involving adsorption of gaseous hydrogen chloride, (b) the main hydrolysis, and (c) completion of the reaction by posthydrolysis. Conditions and associated problems of each temperature controlled step were fully investigated. Thermodynamic calculations concerning heating temperature and mass balance calculations were The made. effect of pretreatments on the hydrolysis was studied. Infrared spectroscopic as well as electron microscopic methods were used to understand the process. \n \nBiomass analysis was fully studied with the result that considerable improvements were made in the procedures for analyzing cellulose. hemicellulose, and lignin and for analyzing the hydrolysis and degradation products from those polysaccharides. It is proposed, for example, that saturated hydrogen chloride replace the usual 72 % sulphuric acid in the standard cellulose analysis procedure.