production of ethanol from molasses in sudanese suger factories

Abstract

The aim of this study is to investigate the potentiality of producing absolute ethanol as a renewable energy from molasses. The Sudan have five operating sugar factories with a considerable amount of molasses as by product. The amount produced per year amounts to 442 thousand Tons approximately, which can be transformed to absolute alcohol. The important properties of molasses mainly sugar content, Brix, viscosity ,and specific gravity were measured .The molasses syrup was diluted with water in a ratio of 50% and the solution was introduced into fermentation reactor, The parameters affecting the rate of fermentation reaction which are time and temperature were cited from the literature and investigated, it was found that the time of the reaction to complete and temperature were 72 operating hours and 37C respectively. The fermented liquid was filtered and its ethanol content was measured and found to be 4.9% on weight basis. The ethanol solution was introduced into a distillation column and the ethanol was collected at the top of the column with a composition of 94w%. Above this composition the process of distillation can not be used to further rectify the ethanol to high composition. This is because at such conditions the solution may form an azotrope. The solution of ethanol-water with composition of 94% was made into absolute alcohol through purification by molecular sieve. This process can give absolute ethanol of 100% purity which is the concentration required to be used as a fuels. The use of ethanol as a renewable source of energy was studied, and it was cited that it has been in use in BRAZIL and USA in various ratios with gasoline. The blend is referred to as E90%, E85% and E10% which means that 90% ethanol is blend with 10% gasoline,85% ethanol is blend with 15% gasoline, and 10% ethanol is blend with 90% gasoline respectively. Estimated economic evaluation was investigated and it was found to be very promising. It was also observed that the effect on environment and global warming is much better than that of fossil fuels. It is concluded that Sudan is qualified to produce commercial quantities of ethanol from molasses.