WORLD AND DOMESTIC EXPERIENCE OF BIOETHANOL PRODUCTION

Abstract

The paper presents an overview of bioetanol production technologies. It is noted that world fuel ethanol production in 2017 amounted to more than 27,000 million gallons (80 million tons). Eight countries, namely the USA, Brazil, the EU, China, Canada, Thailand, Argentina, India, together produce about 98% of bioethanol. In Ukraine, the volume of bioethanol production by alcoholic factories in recent years has been gradually increasing and amounted to 2,992.8 ths. dal in 2017. The production of ethanol as an additive to gasoline, with regard to the raw materials used, as well as the corresponding technologies, is historically divided into three generations. The first generation of biofuels produced from food crops rich in sugar or starch is currently dominant. Production of advanced biofuels from non-food crop feedstocks is limited. Output is anticipated to remain modest in the short term, as progress is needed to improve technology readiness. The main stages of bioethanol production from lignocellulosic raw materials are pre-treatment, enzymatic hydrolysis and fermentation. The pre-treatment process aims to reduce of sizes of raw material particles, provision of the components exposure (hemicellulose, cellulose, starch), provision of better access for the enzymes (in fermentative hydrolysis) to the surface of raw materials, and reduction of crystallinity degree of the cellulose matrix. The pre-treatment process is a major cost component of the overall process. The pre-treatment process is highly recommended as it gives subsequent or direct yield of the fermentable sugars, prevents premature degradation of the yielded sugars, prevents inhibitors formation prior hydrolysis and fermentation, lowers the processing cost, and lowers the demand of conventional energy in general. From the perspective of efficiency, promising methods of pre-treatment of lignocellulosic raw materials to hydrolysis are combined methods combining mechanical, chemical and physical mechanisms of influence on raw materials. One method that combines several physical effects on a treated substance is the discrete-pulsed energy input (DPIE) method. The DPIE method can be applied in the pre- treatment of lignocellulosic raw material in the technology bioethanol production for intensifying the process and reducing energy consumption. Ref. 15, Fig. 2.