A kind of fuel ethanol production method based on high-quality ddgs product

Abstract

The invention belongs to the technical field of biomass energy production, and discloses a fuel ethanol production method based on high-quality DDGS products. unit, the solid phase is recovered, and DDGS products are produced; the top steam of the second refining tower is heated and pressurized by the compressor, and the vapor-liquid equilibrium temperature of the obtained pressurized reflux steam of the second refining tower is higher than the operating temperature of the crude tower tower kettle, and is used as a heating element. The medium is sent to the reboiler of the coarse tower; the top steam of the second purification tower is heated and pressurized by the compressor, and the pressurized adsorption steam of the second purification tower is superheated steam, which does not need preheating operation, and is directly sent to the adsorber A or adsorption unit of the adsorption unit. Device B performs adsorption dehydration operation to obtain fuel ethanol product. This technical solution solves the problems faced by the current mainstream production process of fuel ethanol, such as fermentation mash, waste mash and other solid-containing materials with high heating temperature, reboilers and trays and other equipment are prone to scarring, production is unstable, and affects the quality of DDGS products and other industries. problem.

Description

technical field [0001] The invention belongs to the technical field of biomass energy production, and in particular relates to a method for producing fuel ethanol based on high-quality DDGS products. Using raw materials such as corn, wheat, rice, cassava, sorghum and sweet potato, the production process includes production units such as mash preparation, rectification, adsorption dehydration and waste mash treatment. The disclosed technical solution is aimed at the multi-stage thermally coupled rectification process used in the refining process of the current mainstream production process of fuel ethanol, which causes the solid materials such as waste mash and other solid-containing materials to be heated at a relatively high temperature, and the reboiler and the tray of the rectification production device are easy to condense. Scar, unstable production, the color of DDGS products produced by the subsequent waste mash recovery solid phase becomes black, which affects the quali...

AI Technical Summary

Problems solved by technology

[0004] The technical limitations of the current mainstream fuel ethanol production technology: In order to realize the multi-stage multi-effect coupling utilization of the heat of each rectification tower or equipment in the refining unit, the operating pressure of the recovery tower and rectification tower is artificially increased to achieve the realization of heat The energy level of multi-effect and multi-stage utilization, because the alcohol content of the top of the crude distillation tower is generally designed to be 50-70%, and the reasonable condensation temperature of the top steam is ≥ 45°C, only in this way can the top condenser be used under outdoor temperature conditions The cooling of the conventional circulating cooling water prepared under the following conditions is only feasible and economical in industrial production, and when the minimum operating temperature of the overhead steam of the crude distillation tower is 45°C, the corresponding top operating pressure of the crude distillation tower is ≤- 0.08MPa (there is no special description in this article, the operating pressure is gauge pressure), and the corresponding normal operating temperature of the crude distillation column tank is ≥78°C. The condensing temperature of the distillation tower top steam needs to be ≥80°C, resulting in the normal operating temperature of the corresponding rectification column tower kettle being ≥110°C, and the solid waste mash in the distillation tower kettle is processed under the operating condition of a temperature of ≥110°C ; The chemical characteristics and production practice of DDGS feed all show that when the solid materials such as fermented mash and waste mash are processed under the condition of operating temperature ≥ 100 ℃, the reboiler and tower for processing solid materials such as fermented mash and waste mash The plate is easy to block, and the waste mash discharged from the rectification unit is sent to the waste mash treatment unit to produce DDGS products with high color number, serious carbonization of solid phase, and large loss of nutrients, which cannot meet the minimum requirements of DDGS feed products (See GB / T25866-2010), which can only be sold at a reduced price, which affects the overall economic benefits of fuel ethanol production enterprises. It is necessary to control the treatment temperature of solid materials such as fermented mash and waste mash to ≤100°C to improve the quality of DDGS products; When the operating temperature of the solid waste mash in the distillation tower bottom is required to be ≤ 100°C, the corresponding condensation temperature of the overhead vapor of the distillation tower will be lower than the normal operating temperature of the crude distillation tower bottom, and the rectification tower cannot be used The top material steam heats the crude distillation column reboiler, and the steam consumption of the rectification unit will increase significantly

The steam compressors used in the MVR system are mostly centrifugal steam compressors and Roots compressors. Among them, single-stage compressors have the highest energy consumption efficiency. The single-stage compression ratio of the unit is usually ≤2.4, and there is a certain limit to the increase in temperature rise energy level. , such as 1 ton of secondary water vapor at 70-80°C is usually raised to 90-100°C through single-stage compression of the unit, and the power consumption is about 30-40kw. According to the electricity price of 0.75 yuan / kwh, the operating cost is increased by 22.5-30 yuan, usually The production cost of fresh steam is ≥100 yuan / ton, and the outsourcing price is usually more than 200 yuan

If the energy level of the material vapor is too low, multi-stage compressors are used to increase the temperature and increase the energy level. The energy consumption in the process of boosting and heating is high, and it is not economical to recover the latent heat of the low-energy level material vapor. Reasonable, the energy-saving effect is not obvious, it is necessary to comprehensively consider the benefits brought about by the improvement of DDGS product quality

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