玉米芯发酵法生物制氢

Conversion of Corncob into Biohydrogen by Anaerobic Fermentation

摘要:

在批式培养试验中, 以牛粪堆肥为天然产氢菌源, 玉米芯为底物, 通过厌氧发酵生产氢气。系统考察了底物预处理条件、初始pH值和底物浓度对玉米芯产氢能力的影响。在初始pH 8.0, 1.0%盐酸预处理底物30 min, 底物浓度10 g/L的最佳产氢条件下, 玉米芯最大产氢能力〔每克TVS（总挥发性固体物）产氢量〕和最大产氢速率（每克TVS每小时产氢量）分别为107.9 mL /g、4.20 mL/g·h-1。玉米芯经酸预处理后半纤维素含量由42.2%下降至3.0%, 而酸预处理的玉米芯产氢前后纤维素、半纤维素和木质素含量只有少量变化。产氢菌主要用酸预处理产生的可溶性糖产氢, 故底物的酸预处理对玉米芯的发酵产氢非常重要。用傅里叶变换红外光谱(FTIR)分析显示酸预处理和产氢过程中玉米芯的特征峰发生变化, 酸预处理过程降解了底物纤维素的无定形区和半纤维素, 产氢微生物对纤维素的结晶区有破坏作用。

Abstract:

Biohydrogen production from corncob by dark fermentation was reported for the first time. The effects of the pretreatment condition, substrate concentration and initial pH on the hydrogen production were investigated in batch cultivations. The maximum hydrogen yield of 107.9 mL/g-TVS and hydrogen production rate of 4.2 mL/g-TVS·h-1 were obtained under the condition of 1% HCl pretreating substrate for 30 min, 10 g/L substrate concentration and initial pH8.0. The content of hemicellulose in corncob decreased significantly from 42.2% to 3.0% after HCl pretreatment. The contents of cellulose, hemicellulose and lignin in the acid pretreated corncob decreased slightly in hydrogen producing process. The results indicate that the acid pretreatment of the substrate plays a key role in the conversion of corncob into biohydrogen. Fourier transform infrared spectroscopy (FTIR) was used to study the changes in the corncob composition during the treatment of chemical-microbial process. It was shown that the amorphous domains of cellulose and hemicellulose were hydrolyzed into fermentable asccharides through HCl pretreatment and the microorganisms had a devastating effect on the crystallinitiy of the cellulose.