Process Characteristics of Bioga Production System with Feeding of CO_2

H_2/CO_2利用沼气生产系统的实际应用需求巨大，该系统可以将CO_2固定在系统中，但目前尚无关于气体基质沼气系统的有用资料。本研究通过对沼气池沼气厌氧污泥的加热特性和过程稳定性进行实验研究，为设计和开发沼气生产系统来固定沼气底物中的二氧化碳提供基础数据。为了开发经济的气体底物进料甲烷发酵系统，构建了由枢轴和旋转棒组成的旋转气体排出系统的中试规模发酵罐。热交换是通过来自棒的热沼气与发酵罐中的浆料之间的直接接触进行的。本研究以水和空气代替废浆和沼气，从敌人和物料角度研究了系统的旋转和加热特性。在没有气囊的系统或露天系统中，观察了与气流速率相对应的杆的旋转和从入口空气到水的传热。在有气囊加热或密闭加热系统中，水温逐渐升高，加热模型模拟的温度升高与实际温升拟合。新的供热系统在实际应用中是可行的。在中温条件下，在总HRT为20 d的条件下，研究了产甲烷过程渗滤液对转鼓发酵系统（RDFS）级联过程产酸性能的影响。以新鲜豆粕或菜籽粕为底物，采用叶栅工艺1和叶栅工艺2两种工艺配置进行实验估计。在pH值为4.6 ~ 5.1时，级联工艺1的表观一级水解速率常数为15.8×10^<-3>/d，在pH值为5.2时，级联工艺2的表观一级水解速率常数为14.7×10^<-3>/d，均高于前人的研究结果（9.0×^<-3>/d）。VS的表观降解率为21.1 ~ 25.5%，总VA（乙酸形式）为14.5 ~ 18.6 g/L。在级联工艺1和级联工艺2中，电离VA的占用率分别从30.8%和73.3%增加到68.5%和68.5%。然而，在级联工艺1和级联工艺2中，乙酸的占比从94.3下降到72.6%和43%，而在两个产酸工艺中，丙酸和丁酸的占比都有所增加。虽然在两个过程中，渗滤液的加入都促进了底物的水解，但在级联过程2中观察到高浓度VA对水解速率的不利影响，其表观水解速率常数略小于级联过程1。少

The practice use of H_2/CO_2 utilizing biogas production system which can fix CO_2 into the system is in the huge demand however no useful information on the biogas system with gas substrate is available. In this study, some experiments on the heating characteristics and process stability owing to the anaerobic sludge of the gas utilizing digester is conducted to have fundamental data to design and develop the biogas production system to fix carbon dioxide from the gas substrate.In order to develop the economical methane fermentation system with gas substrate feeding, a pilot scale fermentor with a rotational gas discharge system composed of a pivot and rotational bar was constructed. The heat exchange is conducted by direct contact between the hot biogas from the bar and the slurry in the fermentor. By use of water and air instead of waste slurry and biogas in this study, the rotational and heating characteristics of the system were investigated in the points of enemy and material bal … More ance analysis. The rotation of the bar corresponding to the airflow rate and the heat transfer from the inlet air to the water were observed in the system without the gasbag or the open-air system. In the heating with the gasbag or the closed system, the water temperature increased gradually and the simulated temperature increase by the heating model fitted to the actual temperature rise. The new heating system was concluded to be feasible in practical use.The effects of leachate from a methanogenic process on acidogenic performance in a cascade process of rotational drum fermentation system (RDFS) were evaluated under mesophilic condition and a total HRT of 20 days. Using fresh soybean meal or okara as substrates, two process configurations-Cascade process 1 and 2-were employed to perform the experimental estimation. An apparent first-order hydrolysis rate constant of 15.8×10^<-3>/d for Cascade process 1 at pH values of 4.6〜5.1 and 14.7×10^<-3>/d for Cascade process 2 at pH of 5.2, which were higher than that obtained by a previous study (9.0×^<-3>/d), were obtained. The apparent VS degradation ratio ranged from 21.1 to 25.5% and total VA (as acetic acid) from 14.5 to 18.6 g/L. Occupying ratios for ionized VA increased from 30.8% to 68.5% for Cascade process 1 and to 73.3% for Cascade process 2. However, occupying ratios of acetic acid decreased from 94.3 to 72.6% for Cascade process 1 and to 43% for Cascade process 2 whereas propionic acid and butyric acid ratios increased in both acidogenic processes. Although the addition of leachate promoted hydrolysis of substrate in both processes, the adverse effects of high VA concentration on hydrolysis rate were observed in Cascade process 2, where apparent hydrolysis rate constant was slightly less than that of Cascade 1. Less