两步预处理对厌氧消化产酸纤维酶解和沼气发酵的影响

摘要

对厌氧消化产酸纤维(挥发性脂肪酸生产废渣)进行了酶解糖化和沼气发酵实验研究,探索了乙酸氨水两步预处理对木质纤维素降解、葡萄糖浓度、木糖浓度和沼气产率的影响.结果表明:乙酸氨水两步预处理进一步降解了厌氧消化产酸中的半纤维素和木质素,而且纤维素回收率较高,为77.47％ ～ 81.44％,其中4％乙酸处理和10％氨水处理实验组的纤维素质量分数达到56.82％,半纤维素质量分数仅为7.94％;在上述预处理条件下,酶解糖化效率最高,葡萄糖质量浓度达到47.46g/L,葡萄糖得率为67.73％;同时在此乙酸氨水两步预处理条件下的沼气产率明显优于单独乙酸和单独氨水预处理,获得的最高沼气产率为414 mL/g,有效提高了厌氧消化产酸纤维的产气效率.%The enzymatic hydrolysis and biogas fermentation of anaerobically digested fiber from volatile fatty acids (VFAs) production with rice straw were studied.The effects of two-step pretreatment of acetic acid and aqueous ammonia on the degradation of lignocellulose,glucose concentration,xylose concentration and biogas production were explored.The results showed that two-step pretreatment of acetic acid and aqueous ammonia can further degrade the hemicellulose and lignin in anaerobically digested fiber from VFAs production,and the recovery rate of cellulose was higher,which was 77.47％ ～81.44％.Among them,the mass fraction of cellulose was 56.82％ and the mass fraction of hemicellulose was only 7.94％ for pretreatment of 4％ acetic acid and 10％ aqueous ammonia at 121℃.Under the above pretreatment conditions,the enzymatic saccharification efficiency was the highest,the mass concentration of glucose was 47.46 g/L,and the glucose yield was 67.73％.Furthermore,the biogas production rate of anaerobically digested fiber from volatile fatty acids production pretreated by twostep pretreatment was better than those of acetic acid pretreatment alone and aqueous ammonia pretreatment alone.The highest biogas yield (414 mL/g) was obtained.Two-step pretreatment effectively improved the biogas yield of anaerobically digested fiber from VFAs production.Therefore,the research proved a new biorefinery way of anaerobically digested fiber.