秸秆厌氧发酵产氢气和甲烷的研究
文献类型：学位论文
| 作者 | 成喜雨 |
| 学位类别 | 博士 |
| 答辩日期 | 2011-04-06 |
| 授予单位 | 中国科学院研究生院 |
| 导师 | 刘春朝 |
| 关键词 | Cornstalk Clostridium thermocellum Hydrogen Methane Anaerobic fermentation |
| 其他题名 | Study on hydrogen and methane production by anaerobic fermentation of cornstalk |
| 学位专业 | 生物化工 |
| 中文摘要 | 本文就秸秆发酵产氢气和甲烷的过程加强和放大进行了研究，取得主要成果如下： 1) 对比5株热纤梭菌发酵产氢过程，发现热纤梭菌7072具有最强的纤维降解产氢能力。当以微晶纤维素为底物时，产氢水平最高达158.9 mL/g-cellulose，摩尔氢气产率达到1.2 mol H2/mol-glucose，高产氢水平与热纤梭菌7072发酵过程较少的乳酸和乙醇合成及较低的糖积累有关。氢气产率随着秸秆粒径的降低而相应提高，采用15 mm粒径的秸秆作为发酵原料，氢气产率达37.4 mL/g-cornstalk，与1 mm粒径秸秆发酵产氢时相比降低4.8%，但后者粉碎过程的能耗为前者的12倍。考虑到粉碎过程相对较低的能量输入，后续研究采用较大颗粒秸秆进行发酵产氢。 2) 建立了碱处理结合秸秆两步发酵产氢新工艺，总氢气产率达到74.4 mL/g-cornstalk，秸秆总利用率达到72.8%；产氢发酵液和碱水解液进一步用于产甲烷，总甲烷产率达到205.8 mL/g-cornstalk，碱处理结合秸秆两步发酵产氢耦合甲烷发酵过程的总能量回收率达到70.0%。 3) 在10 L连续搅拌反应器中进行碱处理结合两步发酵产氢工艺的放大，底物浓度在10~20 g/L时搅拌转速设定在80 r/min发酵产氢较好，底物浓度在30~50 g/L时搅拌转速设定在100 r/min发酵产氢较好；在30 g/L秸秆浓度下，最大产氢速率为218.5 mL/L·h，总氢气产率达到58.0 mL/g-cornstalk，容积产氢率达到0.55~0.57 L/L·d，秸秆总利用率为72.3%。在10 L升流式厌氧污泥床中进行产氢发酵液连续产甲烷，在15.0 g-COD/L·d的最适有机负荷下，UASB容积产气率达 4.6 L/L·d，COD去除率达到83.3%，总甲烷产率达200.9 mL/g-cornstalk。反应器规模上秸秆联产氢气和甲烷过程的总能量回收效率达到67.1%。 |
| 英文摘要 | In the current study, enhancement of hydrogen and methane production from cornstalk via anaerobic fermentation and scale-up of this process were investigated. The principal results were as follows. 1) Five strains of C. thermocellum were used for hydrogen production tests. C. thermocellum 7072 produced more hydrogen from microcrystalline cellulose than other strains. The highest hydrogen yield of 158.9 mL/g-cellulose was obtained by using C. thermocellum 7072 and the molar hydrogen yield reached 1.2 mol H2/mol glucose equivalents, which was due to lower level of lactate and ethanol synthesis and less soluble sugar accumulation compared with other strains. Decrease of cornstalk particle size was beneficial to hydrogen production from cornstalk in hydrogen fermentation. The yield of hydrogen production with 15 mm cornstalk reached 37.4 mL/g-cornstalk, which decreased by 4.8% compared with that of 1 mm cornstalk. However, energy consumption of milling process for 1 mm cornstalk was about 12-fold than that of 15 mm cornstalk. Cornstalk with large particle size was used as substrate of hydrogen fermentation in the following studies because of its low energy input in milling process. 2) A novel two-stage hydrogen fermentation process integrated with alkaline treatment (i.e. hydrogen fermentation I, alkaline treatment and hydrogen fermentation II) has been developed in current study. Total hydrogen yield from hydrogen fermentation of cornstalk reached 74.4 mL/g-cornstalk and the overall utilization ratio of cornstalk in this novel process reached 72.8%. Effluents of hydrogen fermentation and alkaline hydrolyzates were further used for methane fermentation. Total methane yield reached 205.8 mL/g-cornstalk. Total energy recovery in two-stage hydrogen fermentation integrated with alkaline treatment and methane fermentation process reached 70.0%. 3) A 10 L continuous stirred tank reactor (CSTR) system was developed for the scale-up of two-stage hydrogen fermentation process integrated with alkaline treatment. Hydrogen yield reached relatively high level at 80 r/min and 100 r/min of stirring speed when substrate concentration was 10~20 g/L and 30~50 g/L, respectively. Maximum hydrogen production rate reached 218.5 mL/L·h in two-stage hydrogen fermentation integrated with alkaline treatment with 30 g/L cornstalk concentration. At the same time, total hydrogen yield and volumetric hydrogen production of cornstalk reached 58.0 mL/g-cornstalk and 0.55~0.57 L/L·d, respectively. The overall utilization ratio of cornstalk arrived at 72.3%. A 10 L up-flow anaerobic sludge bed (UASB) was used for continuous methane fermentation of effluents from hydrogen fermentation. At optimal organic loading rate of 15.0 g-COD/L·d, the COD removal efficiency and volumetric biogas production reached 83.3% and 4.6 L/L·d, respectively. Total methane yield reached 200.9 mL/g-cornstalk in anaerobic fermentation with effluents from hydrogen fermentation and alkaline hydrolyzates. Finally, total energy recovery by co-production of hydrogen and methane with anaerobic fermentation of cornstalk in lab-scale bioreactor systems reached 67.1%. |
| 语种 | 中文 |
| 公开日期 | 2013-09-24 |
| 页码 | 121 |
| 源URL | [http://ir.ipe.ac.cn/handle/122111/1746]  |
| 专题 | 过程工程研究所_研究所（批量导入） |
| 推荐引用方式 GB/T 7714 | 成喜雨. 秸秆厌氧发酵产氢气和甲烷的研究[D]. 中国科学院研究生院. 2011. |
入库方式： OAI收割
来源：过程工程研究所
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