threeTower differential pressure distillation processIntroduction

The differential pressure configuration of this process unit is: differential pressure between distillation tower T502 and crude distillation tower (mash tower) T501, and atmospheric distillation for aldehyde tower.

1. The fermented mature mash from the fermentation section is preheated to about 70 ℃ by the mash first stage preheater E502 (which condenses the crude wine vapor at the top of the mash tower while heating the mature mash) and the mash second stage preheater E507 (which preheats the waste mash to the mature mash for the second time), and then fed into the 24th plate of the mash tower. The mature mash is heated by the bottom steam while descending in the mash tower T501, and the wine vapor is separated from the waste mash while ascending. The waste mash is discharged at the bottom of the tower, and the alcohol content in the waste mash does not exceed 0.05%. It is transported to the environmental protection section. The upstream crude alcohol (low concentration alcohol) is de foamed by the 25 and 26 layer de foaming plates and enters the 1 # preheater. Some of it is condensed, while the uncondensed alcohol gas enters a group of condensers for further condensation. The condensed liquid is indirectly heated by steam condensate and enters the aldehyde tower T503. The crude alcohol partially refluxes (to de foam the crude alcohol gas), while some non condensable gases are still discharged into the atmosphere through a vacuum pump.

Heating method of the mash tower: The top of the distillation tower is heated by the top of the mash tower through the mash tower reboiler E501, which uses a circulating pump for circulation. The fermentation tower operates under negative pressure, which is generated by connecting a vacuum pump through a condenser group.

2. The aldehyde tower operates at atmospheric pressure. The condensate (crude liquor) from the crude distillation tower enters the 16th plate of the aldehyde tower after indirect heat exchange with steam condensate. Head level impurities such as aldehydes and esters move towards the top of the tower and accumulate. The liquor vapor at the top of the tower is mostly refluxed after being condensed by the aldehyde tower condenser, and a small part is extracted as industrial alcohol. Low boiling point gases such as aldehydes and esters and non condensable gases are discharged into the atmosphere through the auxiliary condenser. After separation, the light alcohol at the bottom of the tower is relatively pure, and the remaining distilled water (low tower wastewater) from the refining tower is preheated before entering the distillation tower.

Heating method of aldehyde tower: direct heating with fresh steam and flash steam.

3. The light alcohol concentrate from aldehyde tower T503 is indirectly heated by the distilled water from the refined tower and enters the 18th plate of the distillation tower. While gradually concentrating, impurities such as methanol and aldehydes rise to the top of the tower with alcohol vapor, while some impurities (oils) remain in the upper layers of the feed plate. They are extracted as impurities and sent to the impurities oil separator for oil and alcohol separation. The impurities oil enters the V509 impurities oil storage tank, and the light alcohol is pumped to the mature mash tank after entering the impurities oil tank; Head level impurities can be eliminated by taking out a portion of the reflux liquid as industrial alcohol. High concentration alcohol with a concentration of 95-96% (v/v) can be extracted from the 6-8 plates below the reflux port at the top of the tower as the finished product, cooled and sent to the finished alcohol tank.

The heating method of the distillation tower is to indirectly heat it with fresh steam through the distillation tower reboiler. After the steam condensate is flashed, it is sent by the condensate pump to the crude wine preheater for heat exchange with the crude wine and then returned to the boiler room for reuse. Flash steam is used as part of the heat source for the aldehyde tower.

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