How is industrial alcohol produced?

The industrial production methods of alcohol can be divided into two categories: fermentation and chemical synthesis. 1, fermentation is the production of alcohol by using starch or sugar raw materials under the action of microorganisms. According to the different raw materials, it can be divided into: a. Fermentation of starch raw materials to produce alcohol is the main method to produce alcohol in China at present. It uses starch-containing raw materials such as potatoes, cereals and wild plants to hydrolyze starch into glucose under the action of microorganisms.

The industrial production methods of alcohol can be divided into two categories: fermentation and chemical synthesis.

1. Fermentation method is to use starch raw materials or sugar raw materials to generate alcohol under the action of microorganisms. According to different raw materials, it can be divided into: a. Fermentation of starch raw materials to produce alcohol. This is the main method to produce alcohol in China at present. It uses starch-containing raw materials such as potatoes, cereals and wild plants to hydrolyze starch into glucose under the action of microorganisms, and then further ferment to produce alcohol. The whole production process includes cooking raw materials, preparing saccharifying agent, saccharifying, preparing yeast, fermentation and distillation. B Fermenting molasses raw materials to produce alcohol directly uses the sugar in molasses, adds some nutrients after dilution, and produces alcohol by fermentation under the action of yeast. C sulfite pulp waste liquor is fermented to produce alcohol. After papermaking raw materials are cooked with sulfite solution, the waste liquid contains hexose, which can be fermented by yeast into alcohol, mainly industrial alcohol.

2. The production of alcohol by chemical synthesis is made from the waste gas produced by coke smelting and petroleum cracking through chemical synthesis reaction. Production methods can be divided into indirect hydration method and direct hydration method. Indirect hydration method is also called sulfuric acid hydration method. Its production process is to add ethylene and sulfuric acid to produce ethyl hydrogen sulfate, and then hydrolyze to produce ethanol and sulfuric acid. The disadvantage of this method is serious corrosion to equipment and high acid consumption. The advantages of this method are low purity of feed gas, simplified equipment and easy start-up. B In the presence of phosphoric acid catalyst, ethylene and steam are directly hydrated at high pressure and high temperature, and can be directly added to produce alcohol. This method requires the purity of ethylene in the feed gas to be above 98%, and it requires a special method to separate and crack various components in it, which puts forward higher requirements for equipment and materials, but this method has simple steps and no corrosion problems.