预处理方法对香蒲厌氧发酵联产 H2-CH4效能的影响

Effect of Different Pre-Treatment on Hydrogen and Methane Coproduction during Typha Anaerobic Fermentation Process

通过厌氧发酵动力学分析、还原糖及其他代谢产物变化情况,结合香蒲微观结构解析,系统研究酸(HCl)、碱(NaOH)、酶(纤维素酶R-10)3种预处理对水生植物厌氧发酵联产H2-CH4的影响.结果表明:香蒲分别经酸、碱、酶3种预处理后,厌氧发酵联产累积H2、CH4产量及含量均显著提高,c(HCl)、c(NaOH)均为1.0 mol/L,w(纤维素酶R-10)(以底物计)为10 mg/g时,预处理最佳.其中1.0 mol/L NaOH预处理香蒲效果最佳,φ(H2)(H2含量)达30.09%,累积产H2量(以香蒲干质量计)达11.39 mL/g;φ(CH4)(CH4含量)最高达67.48%,累积产CH4量(以香蒲干质量计)达41.87 mL/g;还原糖利用率达50.87%,sCOD(溶解性化学需氧量)利用率达66.17%.纤维素酶预处理后香蒲产CH4能力显著提高,产CH4阶段φ(CH4)最高为71.39%,累积产CH4量达46.32 mL/g,还原糖利用率达72.10%.扫描电镜微观结构分析表明,碱预处理对香蒲纤维素结构破坏程度最大,可有效增加香蒲与微生物接触面积,有利于厌氧发酵联产H2-CH4工艺的快速启动和稳定运行.

The influence of acid, alkali or enzyme pretreatments on the co-production of hydrogen and methane during the typha anaerobic process was studied based on anaerobic fermentation kinetics and the evolution of reduced sugar and other metabolites combination with aquatic plant microstructures. The results showed that, after the acid, alkali or enzyme pretreatment, the content of hydrogen and methane significantly increased in anaerobic fermentation process, and the optimum pretreatments were 1.0mol/L HCl, 1.0mol/L NaOH and 10mg/g （TVS） cellulose enzyme R-10, respectively. The best pretreatment of typha was 1.0mol/L NaOH. The hydrogen content was up to 30.09%, the cumulative hydrogen production 11.39mL/g （TVS）, the methane content up to 67.48%, the cumulative methane yield 41.87mL/g （TVS）, the reduced sugar utilization rate 50.87%, and the sCOD removal rate 66.17% after the best pretreatment. In addition, the methane production ability was significantly improved after enzyme pretreatment as well. For instance, the methane content was up to 71.39% at the methanogenic phase, the accumulated methane production 46.32mL/g （TVS）, and the reducing sugar utilization rate up to 72.10%. The results of SEM showed that the cellulose structure of aquatic plants was severely damaged, and the superficial area of plants and microbes increased effectively after alkali pretreatments, which was beneficial to the rapid start-up and stable operation of the co-production process in anaerobic fermentation.