Study On Bio-energy Recovery Technology From Organic Solid Waste By Microorgnism Aerobic Degradation

Aiming at the production of organic solid wastes and biomass energy reserves in it in our country, combining with the present situation of building energy consumption, the article analyzes the match of the calories from the degradation of organic solid waste by aerobic microbial oxidation decomposition and building calories daily needs. Proposes the idea of recycling the calories from the degradation of organic solid waste for building heating, designs and constructions of the experimental platform and does a series of experimental research. On the basis of the relevant physical parameters of the experiments, references the previous microbial research and porous media theories, establishes the mathematical model of heat and mass transfer of the biochemical reaction process. Gets the best process parameters, and using experimental data to validate the model. The results show that:(1)This article conducts three series of experiments, contrast experiment I and II, proves the microbial inoculants has significant role in promoting the reaction. Furthermore, the arrangements of vent pipes in the reactor is one of the key factors in the success of the experiment, the air supplies from the four walls and recovers from the center of the reactor has a better experimental results. The reaction of 175kg materials with the average ventilation rate of 2.98m3/h can obtain the highest 63.1 ℃air, and the high-temperature phase accounted for 94%of the total time of the experiment under the outdoor temperature at 27℃～31℃. The whole process recoveries a total heat 47.7kWh, the unit heat recovery rate of volume of the reactor is 851.3W/m3, the unit heat rate recyclable materials 6.37 W/Kg. Experiments III increases the average ventilation rate to 4.23m3/h to compare with experiments II, and the results show that the air temperature dropped obviously, the unit heat recovery rate of volume of the reactor is 770.57W/m3.(2)Use experimental data to validate the model, the results show that temperature trends basically the same, experimental and predicted values match well in the heating and cooling process. However, experimental value is higher than the predicted value in heating process, this is due to the addition of biological inoculants in the experiment.(3)Based on the theoretical model, analysis the influence of the ventilation rate, the initial moisture content, the initial temperature on the aerobic decomposition process, obtains the optimum parameters:the optimum ventilation is 3m3/h, that is 16.7m3/(h·t) for 175kg materials, the optimum initial water content of 70% to 75%, and the water needs to be supplied again in 80h. The higher the initial temperature,the better, however, there is no significant effect to continue to improve the initial temperature when it reaches 30℃.Under the optimum process parameters, the reaction temperature raises quickly, and the high-temperature phase lasts long, the heat recovery rate can achieve 795.6～812.5W/m3.(4)Analyzes the feasibility of applying the aerobic decomposition heat recovery for building heating, designs a continuous heating system with auxiliary heat source according to the results of experimental and theoretical studies. For example, use a combined system for 5 families in Xuzhou, the economic analysis shows that the aerobic decomposition heat can meet the requirements of radiant heating, and the payback period of the equipment investment is approximately 3 years.