Technology for Obtaining Biogas From Agricultural Plant Waste With High Bioavailability Activated by the Method of Steam Explosive Treatment

Abstract

The research was carried out in order to obtain new data on effective methanogenesis during fermentation of lignocellulose raw materials activated by steam blasting. Vegetable agricultural waste - wheat straw and spelt husk are used as raw materials. Activation of pre-crushed and moistened (in the medium "acetic acid-water" in a ratio of 1:19) to 130...140% of the raw materials were carried out on a steam-explosive hydrolysis unit at a temperature of 160, 190 and 220 ° C for 5 minutes. After analyzing the component composition of the initial and activated raw materials according to standard methods, the samples were subjected to microbiological treatment in the presence of the enzyme preparation SUKAZYM ZH-1002 (Shandong, China) in powder form. Conditions for methane fermentation: the concentration of the substrate is 166 g / l, the hydromodule is 1:6, the consumption of the enzyme preparation is 0.05 g / g of the substrate, pH 6.5 ...7.5, temperature 32...35°C, without stirring and without oxygen access, duration - 46 days. The amount of gas produced was determined by the volume method daily, as well as by the accrual method. The content of CO2, CH4, N2 and H2 was determined on a GAMMA-100 gas analyzer; the calorific value was determined on a differential scanning calorimeter DSC 823e. Steam-explosive activation of agricultural plant waste increases the bioavailability of raw materials, which allows generating 1.4...1.8 times more biogas on the activated substrate compared to samples without treatment. The optimal temperature for steam blasting of wheat straw and husk of spelt can be considered 190 and 160 ° C, the duration of methane fermentation is 44 and 40 days. accordingly. With these parameters, the maximum biogas yield of 137.3 and 141.7 ml per 1 g of substrate is achieved with a methane content of 56 and 54 vol. %. The calorific value of biogas is 6692 and 6214 kcal/m3, respectively.