Distillation dehydration device and process for co-producing ethanol fuels and custom grade edible alcohols

Abstract

The invention discloses a distillation dehydration device and a distillation dehydration process for co-producing ethanol fuels and custom grade edible alcohols. The device comprises a molecular sieve adsorption / desorption tower, a coarse fractionating tower, an assembled tower, a rectifying tower, a methanol tower and mash pre-heaters, wherein the wine steam of the assembled tower, after compressed by an ethanol steam compressor, is used as the heat sources and raw material wine steams of the coarse fractionating tower and the methanol tower; the wine steam of the rectifying tower is used asthe heat source of the assembled tower; and the wine steam of the coarse fractionating tower, the anhydrous alcohol steam and the wine steam of the methanol tower are respectively used as the heat sources of the first, second and third mash pre-heaters. The device can simultaneously produce ethanol fuels and custom gradeedible alcohols, and can separately produce ethanol fuels or custom grade edible alcohols. The device and the process of the invention have the advantages that, because a multi-effect energy coupling mode is adopted, compared with an original process, the energy consumption ofthe process of the invention is greatly reduced, and the steam consumption of the ethanol fuel per metric ton is reduced to 1.1 to 1.5 t / t, compared with the steam consumption of 1.5 to 2.0 t / t in the original process, the steam consumption is down by 25 to 35 percent without consuming high-grade steams (more than 0.7 MPag); and the steam consumption of the custom grade edible alcohol per metric ton is reduced to 1.2 to 1.4 t / t, compared with the steam consumption of 1.9 to 2.5 t / t in the original process, the steam consumption is down by 35 to 50 percent.

Description

technical field [0001] The invention relates to an alcohol distillation device, in particular to a distillation and dehydration device and process for co-production of fuel ethanol and common edible alcohol. Background technique [0002] With the unrestrained use of fossil energy, it has caused serious environmental pollution, climate warming and other problems, and has also led to the depletion of fossil energy. Countries all over the world regard the development of renewable energy represented by biomass energy as an important part of future energy strategy. The production of anhydrous ethanol from renewable non-food biomass and the addition of auxiliary agents to fuel ethanol can be used as an effective substitute for gasoline and other fuels. [0003] Traditional fuel ethanol distillation and dehydration units are roughly divided into two-tower differential pressure distillation liquid-phase dehydration process, double-tower differential pressure distillation gas-phase ...

AI Technical Summary

Problems solved by technology

Among them, the operating pressure of the high-pressure tower reaches 450-550kPa (gauge pressure), the temperature at the bottom of the tower reaches 155-165°C, and the steam pressure requirement reaches 0.7-0.9MPa (gauge pressure), which reduces the power generation of the thermal power plant and reduces the overall economic benefits. ;

[0005] (2) The temperature at the bottom of the combined tower is relatively high, especially for the device that uses corn fermented mash as raw material. Since the temperature at the bottom of the tower reaches 115-125°C, the amino acids and sugars in the waste mash undergo Maillard reaction at high temperature. Make the color of the feed deepen, affect the grade and selling price of feed products;

[0006] (3) The main heat exchange equipment has a large investment, and the heat exchange effect is poor: due to the mature mash and waste mash containing a large amount of high-viscosity solids, the heat exchanger is often blocked, which seriously affects the heat exchange effect; the waste water of the crude wine preheater The temperature at the end reaches about 160°C, and the high temperature resistance requirements of the gaskets of the plate heat exchanger are higher, and liquid leakage is prone to occur, which greatly increases the overall energy consumption;

[0007] (4) In the process provided by the patent application CN 101580457A, there is a reflux of the dealdehyde section (tower) at the top of the negative pressure tower, which requires a large amount of cold utilities to condense, increasing steam consumption

[0009] In addition, the traditional alcohol distillation (dehydration) device can only realize the production of single products such as general-grade edible alcohol and fuel ethanol, but cannot produce two products of general-grade edible alcohol and fuel ethanol at the same time, nor can it realize two products according to market demand It is convenient to switch, and the construction of two sets of product distillation (dehydration) equipment requires a large investment

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