Analysis of water consumption in technological processes of grain processing for alcohol

Abstract

The article deals with the issues of water consumption in the production of ethyl alcohol from grain raw materials. The data on its demand for technological needs (for preparing a batch), as a refrigerant, for steam generation, for household needs are given. It is shown that water in specific terms is the most voluminous raw material resource (up to 1600 m3/1000 decaliters), but at the same time it is practically not consumed as a reagent for technological purposes. The analysis of options for the reuse of water was carried out and the possibility of reducing its consumption to 200 m3/1000 decaliters was shown, due to the repeated use of cooling water, by introducing a circulating water supply system, constant circulation of water through the cooling towers, where it is cooled. It is also noted the possibility of complete exclusion of water in the cooling processes through the use of "dry" cooling towers. In this case, the circulation of the refrigerant (for example, ethylene glycol) is carried out in a closed cycle. The relevance of using a single water flow for sequential cooling of semi-products is also shown: fermenting and saccharified wort, boiled mass using efficient heat exchangers of a spiral, plate type. An example is given of reducing water consumption for steam generation by reusing "conditionally clean" steam condensate formed in systems of "dull" heating of semi-finished products. An analysis was made of reducing the consumption of water for the preparation of the mixture due to the processing of raw materials in conditions of high concentrations and the reuse of the stillage filtrate. In addition to saving heat and energy resources, this reduces the volumes of formed stillage and industrial effluents. As a result, the costs of their processing and purification are reduced. A list of measures has been proposed that will reduce water consumption by 10 or more times and increase the profitability of alcohol production by 2–2.5%.