Study on the Conditions of Pretreating Vinegar Residue with Sodium Hydroxide for Simultaneous Saccharification and Fermentation to Produce Alcohol and Xylose

In order to reduce the environmental problems caused by vinegar residue emission, simultaneous saccharification and fermentation technology was used to produce alcohol and xylose from vinegar residue. Due to pretreatment of vinegar residue is vital for simultaneous saccharification and fermentation, uniform experimental designs were used to investigate each of the 5 factors involved in sodium hydroxide and xylanase pretreatment. The results showed that the optimal conditions for vinegar residue pretreatment were determined as solid-to-liquid ratio of 1:11(W/V), NaOH concentration of 2.2%, pretreatment temperature of 71 °C, pretreatment time of 80 min and xylanase usage of 0.3 mL/g. Under this condition, the total sugar yield of vinegar residue was 664 mg/g. Following simultaneous saccharification and fermentation, alcohol and xylose were produced, the yields of ethanol and xylose were 319 mg/g and 179 mg/g, respectively. Therefore, the feasibility of producing alcohol and xylose by enzymatic degradation of vinegar residue was achieved.