不同操作条件下果蔬垃圾厌氧发酵产乙醇的规律

Ethanol Production from Anaerobic Fermentation of Fruit and Vegetable Wastes Under Different Operating Conditions

果蔬垃圾可作为厌氧发酵产乙醇的底物,发酵效果受到多种因素的影响。本研究针对混合果蔬垃圾,分析了不同条件下厌氧发酵产乙醇的规律,操作条件包括水热预处理灭菌、添加纤维素酶、接种酵母菌等。结果表明:添加纤维素酶和酵母菌均有利于提高系统的水解效果,但添加纤维素酶对于系统发酵产乙醇的促进作用有限,添加酵母菌则可有效提高乙醇产率,仅添加酵母菌组和添加酵母菌与纤维素酶组的每单位果蔬垃圾有机质的乙醇产量分别达(0.164±0.040)g/g和(0.161±0.039)g/g,较对照组分别提高34.23倍和33.45倍;水热预处理前后果蔬垃圾的发酵规律相似,但水热预处理促进了底物的水解,提高了各产物的产率;水热预处理与接种酵母菌联合处理条件下,乙醇产量最高,浓度可达(16672.09±2304.85)mg/L,产率可达(0.233±0.032)g/g。因此,添加0.5%质量的酵母菌可改变体系的发酵类型,使得乙醇成为主要产物,而水热预处理与添加酵母菌联合应用可获得最高的乙醇产率。

Fruit and vegetable wastes can be used as substrates for ethanol production by anaerobic fermentation,and the fermentation effect is affected by various factors.The pattern of ethanol production by anaerobic fermentation of mixed fruit and vegetable wastes under different conditions was analyzed,including hydrothermal pretreatment and sterilization,addition of cellulase,and inoculation of yeast.The results showed that the addition of cellulase and yeast were both beneficial to improve the hydrolysis effect of the system.The addition of yeast could effectively improve the ethanol production rate,while the addition of cellulase had a limited effect on the promotion of ethanol production in the system.The ethanol production rate of adding yeast and yeast with cellulase reached(0.164±0.040)g/g and(0.161±0.039)g/g per unit of fruit and vegetable waste organic matter,respectively,which was 34.23 times and 33.45 times higher than the control group.The fermentation pattern of fruit and vegetable wastes before and after hydrothermal pretreatment was similar,but hydrothermal pretreatment promoted the hydrolysis of the substrate and increased the yield of each product.The highest ethanol yield was obtained under the conditions of combined hydrothermal pretreatment and inoculation of yeast.Under this condition,the final concentration of ethanol could reach(16672.09±2304.85)mg/L with a yield of(0.233±0.032)g/g.Therefore,the addition of 0.5%mass of yeast could change the type of fermentation of the system,which made ethanol become the main product.The combined application of hydrothermal pretreatment and addition of yeast resulted in the highest ethanol yield.