Optimization of bioethanol production from cheese whey and corn steep liquor using mixture desing

Resumo

Apart from creating many positive impacts, the growth of agribusiness has also generates concerns about the production of large amounts of undervalued by-products. Cheese whey and corn steep liquor (from corn flour production, a typical Brazilian food) are among these by-products that can be potential raw materials for obtaining new products such as bioethanol. The objective of this study was to apply an experimental design tool to examine different worts with cheese whey and corn steep liquor for the production of bioethanol. The worts containing 100 % corn steep liquor, and 25 % cheese whey with 75 % corn steep liquor supplemented with glucose were considered the best for the production of bioethanol, with fermentation efficiency reaching around 90 % for both of them. The use of pasteurization and antibiotics was effective in controlling lactic acid production, which results from bacterial contamination. The use of antibiotics showed advantages by reducing the maximum growth rate of yeast, which was reflected in higher rates of fermentation efficiency. The results obtained allowed reaching a high level of ethanol productivity.