Keywords: ethanol yield, solid substrate fermentation, sweet sorghum, techno-economic assessment, sugar content, internal return rate, ethanol price
The techno-economic assessment for the plant of solid substrate fermentation of refining ethanol from sweet sorghum stalk
Technological process of a pilot plant of solid substrate fermentation of refining ethanol from sweet sorghum stalk was described. The techno-economic assessment of the pilot plant was carried out with cost and profit method. Results showed that ethanol yield was 90% and the spent residue of fermentation can be converted to forage. In addition, Net Present Value (at discount rate of 10%), Internal Return Rate and Profit/Cost of financial analysis in project level were 94.30 × 104 Yuan, 19.86% and 1.07, respectively. The dynamic payback period was 7-8 years. As a result, the project was feasible. The ethanol price had highest effect on the changes of Internal Return Rate of the project. And annual operation cost and initial investment ranked second and third, respectively. Under the condition of fixed capacity of fermentation equipment, the effects of sugar content of sweet sorghum stalk and ethanol yield on the changes of internal return rate were the same as that of ethanol price. Therefore, the project had a big market potential with the increase of ethanol price.