The Hydrolysis Process Research Of Vinasse And Application Of Fermentation To Produce Fumaric Acid

Biomass is a new type of renewable energy sources that can replace the traditional fossil energy source.As a kind of biomass resources, vinasse is rich in lignocelluloses. A large amount of vinasse is producted in our contury. However, except a few used as animal feed, most of the vinasse is burned directly. The buring of vinasse has brought seriously environmental problems and caused the waste of resource. So, the efficient use of vinasse alleviates the energy crisis to some extent. At the same time, it can also reduce the pollution of the environment.In this paper, the reducing sugars which contained in vinasse was released through the way of dilute sulphuric acid hydrolysis. To increase the concentration of reducing sugur, process conditions were optimized by investigating the effect of hydrolysis temperature, hydrolysis time, solid-liquid ratio, and sulfuric acid concentration. And the highest sugur yield was 245 mg·g-1 vinasse. The optimum condition was 120℃,100min, solid-liquid ratio 1:10,2%H2SO4.At the optimum condition,25g·L-1 reducing sugur concentration was obtained in hydrolysate.After treated with calcium hydroxide and activated carbon, the color of the hydrolysate changed from brown to colorless transparent, and the furfural was removed completely. The concentration of reducing sugar in treated hydrolysate was about 20g·L-1, and sugar loss rate was about 20%. As the low reducing sugur concentration in the treated hydrolysate, the yield of fumaric acid could only reach 3.5·g·L-1 and the biomass was very low while used it directly as fermentation carbon source. When the hydrolysate concentrated by four times, the concentration of sugar was about 80g/L. And the yield of fumaric acid could reach 15g·L-1 when fermentation by concentrated hydrolysate,which was higher than fermentation by 80g·L-1 xylose.The reducing sugar concentration could be improved through concentration, but a large amount of energy would be consumed. By the way of adding sugar, the sugar concentration could also reach 80g·L-1. Among them, adding mixed sugars (glucose, xylose, arabinose=4g:8g:1 g), the production of fumaric acid was 22.5g·L-1 after 144 h fermentation, when adding mixed sugars (glucose, xylose, arabinose=4g:8g:1g) into hydrolysate. The production of fumaric acid was 21.7g·L-1 when adding xylose and 21.3 g·L-1 by adding glucose in the same condition of fermentation. Adding carbon source could effectively improve the production of fumaric acid.The results indicate that hydrolysate can completely or partly replace glucose and xylose as microbial fermentation carbon source.