Yoshida Hiroyuki, Tokumoto Hayato, Ishii Kyoko, Ishii Ryo
Department of Chemical Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan.
Bioresour Technol. 2009 Jun;100(12):2933-9. doi: 10.1016/j.biortech.2009.01.047. Epub 2009 Feb 28.
A novel biomass-energy process for the production of methane from sewage sludge using a subcritical water (sub-CW) hydrolysis reaction as pretreatment is proposed. The main substances of sewage sludge hydrolyzed by sub-CW at 513 K for 10 min were acetic acid, formic acid, pyroglutamic acid, alanine, and glycine. Fermentation experiments were conducted in an anaerobic-sludge reactor for two different samples: real sewage sludge and a model solution containing components typically produced by the sub-CW pretreatment of sewage sludge. In the experiment for the sub-CW pretreatment of sewage sludge, methane generation was twice that for non-pretreatment after 3 days of incubation. In the model experiment, the methane conversion was about 40% with the application of mixture of organic acids and amino acids after 5 days of incubation. Furthermore, the methane conversion was about 60% for 2 days when only organic acids, such as acetic acid and formic acid, were applied. Because acetic acid is the key intermediate and main precursor of the methanogenesis step, fermentation experiments were conducted in an anaerobic-sludge reactor with high concentrations of acetic acid (0.01-0.1M). Nearly 100% of acetic acid was converted to methane and carbon dioxide in 1-3 days.
提出了一种新型生物质能工艺，该工艺以亚临界水（sub-CW）水解反应作为预处理，用于从污水污泥中生产甲烷。在513K下，亚临界水对污水污泥水解10分钟后的主要物质为乙酸、甲酸、焦谷氨酸、丙氨酸和甘氨酸。在厌氧污泥反应器中对两种不同样品进行了发酵实验：实际污水污泥和含有污水污泥亚临界水预处理典型产物成分的模型溶液。在污水污泥亚临界水预处理实验中，培养3天后，甲烷生成量是非预处理的两倍。在模型实验中，培养5天后，应用有机酸和氨基酸混合物时，甲烷转化率约为40%。此外，仅应用乙酸和甲酸等有机酸时，2天内甲烷转化率约为60%。由于乙酸是甲烷生成步骤的关键中间体和主要前体，因此在含有高浓度乙酸（0.01-0.1M）的厌氧污泥反应器中进行了发酵实验。1-3天内，近100%的乙酸转化为甲烷和二氧化碳。
