ИСТИНА

Currently receiving fuel from renewable agricultural or industrial wastes is very important. This process consists in the conversion of carbohydrates from raw materials (it means biomass) of agro-industrial complex (AIC) into hydrocarbons or hydrocarbon fragments. An anaerobic conversion of biomass into biogas is the most promising in this respect. This conversion occurs through the stage of formation of various fatty acids. However, the process of methane production has several disadvantages. It is a relatively low speed functioning of a methane producing consortium, which is limited in most cases with degradation of polymers, such as lignin and cellulose (with hard digestion of lignin), and the instability and even locking the process of methane production because of pH lowering. So a purpose of the submitted paper is to get the overproduction of volatile fatty acids by blocking the process of the methane production. Further volatile fatty acids with a process of etherification under supercritical conditions would be turned into effective additives to any hydrocarbon fuels. It was studied an influence of the modification of the method preprocessing of the biomass (solid wheat straw and sawdust of coniferous breeds of trees and a lignin), adding of microorganisms Clostridium acetobutylicum into the reactivated acidogenic biocatalyst and the dilution of the preprocessed biomass with glycerin on the amount and ratio of the volatile fatty acids (VFA) and ethanol. Consecutive application of processes of an oxidative depolymerization and acid hydrolysis instead of the oxidative depolymerization only allowed to receive the high contents of soluble organic substances from 44 till 94 gCOD/l and increased concentration of the restoring sugars from 1% till 22 - 36%. The comparative analysis of results of two various methods of preprocessing of the biomass on such difficult decomposed biomass samples as sawdust and the lignin, showed the increase of the amount the VFA and ethanol by 18% and 2%, respectively. Adding of microorganisms Clostridium acetobutylicum into the biocatalyst increased the amount of VFA and ethanol, and the amount of the butyric acid and ethanol from biomass of straw was the maximum of 27 and 17.4%, respectively, as compared with the other substrates in the similar process. Addition of glycerin allowed to increase the amount of butyric and acetic acids in the process of the conversion of the preprocessed biomass. So the maximum amount of butyric acid and VFA of 32 and 72%, respectively, were obtained on the preprocessed straw diluted twice with glycerin.