I made a mistake on the last sentence. In the final product analysis, the alcohol content must reach 99.4% (mass fraction).

Ethanol is an excellent solvent, widely used in pharmaceuticals, paint, and other industries. The traditional production methods include molecular sieve dehydration, such as azeotropic distillation and membrane separation. Ethanol production methods, because of their high energy consumption and pollution to the environment, have caused many to consider atmospheric and vacuum distillation as an option for saving energy and reducing pollution. During the ethanol production process, the first step is liquid to alcohol pretreatment, and then an operating pressure of -0.091 MPa should be achieved for atmospheric and vacuum distillation reflux ratio within two hours of processing. In the final product analysis, To analyze the product, the alcohol content must reach 99.4% (mass fraction).