以甜高粱渣为原料发酵生产乙醇

研究了以甜高粱渣为原料生产燃料乙醇：甜高粱渣经磷酸水解，水解液中和浓缩后接入管囊酵母（Pachysolen tannophilus）发酵生产乙醇，水解残渣加入纤维素酶和酿酒酵母（Saccharomyces cerevisiae）同步糖化发酵。通过正交实验研究了磷酸水解甜高粱渣的条件，最优条件为：磷酸浓度80g/L、反应温度120℃、反应时间80min、固液比1∶10，最大还原糖得率为0.3024g/g干物料。水解液管囊酵母发酵最大乙醇浓度为14.5g/L；水解残渣同步糖化发酵，当底物浓度为5%时最大乙醇浓度达5.4g/L。总乙醇产率为0.147g/gDM。

Fermentation of ethanol from sweet sorghum residue

Sweet sorghum residue was hydrolyzed with phosphoric acid under mild conditions. Orthogonal experiments were carried out in order to study the main factors affecting the concentration of sugar produced in the hydrolysis reaction, namely reaction temperature, phosphoric acid concentration, time, and solid∶liquid ratio with the optimum conditions being found to be 120 ℃, 80 g/L, 80min and 1∶10, respectively. Under these conditions, 0.3024 g sugar/g dry material was obtained. The resulting liquid phase hydrolysate was fermented with Pachysolen tannophilus whilst the hydrolysis residue was subjected to simultaneous saccharification and fermentation (SSF) with cellulase (60 FPU/g dry material) and Saccharomyces cerevisiae. The maximum ethanol concentration produced by fermentation of the liquid hydrolysate was 14.5 g/L, whilst SSF of the hydrolysis residue afforded an ethanol concentration of 5.4 g/L when the solid content was 5%. The total ethanol yield was 0.147 g/g dry material, which is viable for industrial production of ethanol from sweet sorghum residue.