With the application and promotion of large-scale biogas project, economic analysis and evaluation of large-scale biogas project are particularly important. However, the benefits of biogas project embodied in the economic, social, ecological, and many other aspects have dispersion, which leads to production decisions in a gray state and investment in conformity. In this paper, the biogas project in Zhuangda village, Zhaozhou County, Heilongjiang province is taken as an example, the supply and demand of funds in project operation are analyzed quantitatively by using system dynamics theory so as to study the economics of biogas project comprehensively, which can provide scientific guidance for evaluating the construction and operation of large and medium-scale biogas project objectively and lay a solid theoretical foundation for the commercial operation in biogas industry.

High-concentration anaerobic fermentation of dairy manure was investigated using an anaerobic batch reactor under laboratory conditions at 20°C. Daily average productive rate of CODVFA was used as response functions, and three factors (temperature, liquid concentration, and retention time) were selected as input variables in the process of hydrolysis and acidogenesis of dairy manure. The study used a central composite rotatable orthogonal experimental design. The influential regularities of every parameter on every index were analyzed with a single-parameter method. The ranges of temperature, liquid concentration and retention time were 25°C to 35°C, 6% to 10%,and 2 to 12 days respectively. Experimental results showed that daily average productive rate of CODVFA was greatly influenced by temperature, with retention time a secondary influence, and liquid concentration having the least influence.

With the application and promotion of large-scale biogas project, economic analysis and evaluation of large-scale biogas project are particularly important. However, the benefits of biogas project embodied in the economic, social, ecological, and many other aspects have dispersion, which leads to production decisions in a gray state and investment in conformity. In this paper, Great Northern Wilderness beef cattle industry in Heilongjiang province is taken as an example for large-scale biogas electricity generation project. The supply and demand of funds in project operation are analyzed quantitatively by using system dynamics theory so as to do study and perform optimal analysis comprehensively on the economics of biogas project, and to explore the effective scheme of improving the proportion of income against cost. This study can provide scientific guidance for evaluating the construction and operation of large and medium-scale biogas project objectively and lay a solid theoretical foundation for the commercial operation in biogas industry.