摘要
Bioethanol is a renewable,clean energy and a very important basic chemical raw material,improving production efciency and reducing production cost are the goals pursued by ethanol enterprises.Adding acid protease in the process of producing ethanol from grain will have many efects on fermentation,one of the most concerned efects is to increase liquor yield.Acid protease can hydrolyze the protein in cereals to produce free amino acids that can be used directly by yeast,thus reducing the amount of sugar consumed for amino acid metabolism,and allowing more sugar to be converted to ethanol.The application method and efect of acid protease in the industrial production of ethanol from corn were studied in this study,the results showed that the addition of acid protease at the dosage of 10 U/g(raw material)during yeast seeding could replace urea,promote yeast proliferation,reduce the infection rate,shorten the fermentation period by 7.5 h and increase the alcohol yield of raw materials by 0.33 percentage point.When acid protease was used in ethanol production line with an annual output of 180,000 tons,the net proft increased by at least US$4900/day compared with the control process.It is hoped that this study can lay a foundation for the application of acid protease in ethanol industry.
