Distillation Process (double Coarse Tower Three Effect Differential Pressure)

Distillation process(double coarse tower three effect differential pressure)

I. Overview

This process is suitable for the production of ordinary grade alcohol and fuel ethanol. It is a triple-effect thermal coupling distillation technology using double coarse towers to produce ordinary grade alcohol. The process of double coarse tower distillation to produce generation-grade alcohol is mainly composed of fine tower II, coarse tower II, fine tower I, and coarse tower I. A system contains two coarse towers, two fine towers, one tower inlet steam and four towers, using the differential pressure and temperature difference between the tower and the tower to transfer heat step by step through the reboiler to achieve the purpose of energy saving. In the work, two coarse towers feed and two fine towers take alcohol at the same time. At present, this process has been popularized in many general grade alcohol and fuel ethanol manufacturers.

II. Process characteristics

1. Low energy consumption, 1.2 tons of alcohol steam consumption.

2. The primary steam heats the refined tower II through the reboiler, the wine steam at the top of the refined tower II heats the coarse tower II through the reboiler, the wine steam at the top of the coarse tower II directly heats the refined tower I, and the wine gas at the top of the refined tower I heats the coarse tower I through the reboiler. One tower inlet steam, four tower work, so as to achieve three effects of thermal coupling, to achieve the purpose of energy saving.

3. Use the differential pressure and temperature difference between the tower and the tower to transfer heat step by step through the reboiler, which can maximize the use of heat, thus effectively saving energy.

III. Process flow

IV. Heating method

The key of energy saving in this process is the heating method. The primary steam indirectly heats the fine tower II through the reboiler, and the steam condensate preheats the mature fermentation liquor and crude alcohol before returning to the boiler soft water tank for reuse. The fine tower II wine steam is heated by the reboiler of the coarse tower II; Fine tower I wine vapor is heated by reboiler coarse tower I.

In this process, the coarse tower I is the negative pressure tower, the coarse tower II and the fine tower I are the normal pressure tower, and the fine tower II is the positive pressure tower. Use pressure difference, temperature difference step by step heating. One tower inlet steam, three towers work, so as to achieve three effects of thermal coupling, to achieve the purpose of energy saving.

V, material direction

After two stages of preheating, the fermentation mash first enters the top of the coarse tower I for dealdehyde, and then the mash is divided into two parts by the distributor: one part enters the coarse tower II and the other part enters the coarse tower I. After the fermentation mash enters the coarse tower II, the liquor is removed from the bottom of the tower, the coarse liquor gas enters the refined tower I to concentrate and discharge impurities, and part of the finished alcohol is taken out on the upper side line.

The light wine at the bottom of the fine tower I and the wine vapor condensate at the top of the coarse tower I are mixed into the fine tower II, concentrated and discharged in the fine tower II, and part of the finished alcohol is removed from the upper side line, and the impurities with high boiling point such as fusel oil are removed from the middle and lower part of the fine tower II.

VI, general alcohol energy consumption and quality comparison table