Research On The Discipline Of Generating Gas Of Straw-cow Dung As Biogas Feedstock

China is a huge geographical country with mostly rural population and a largebiomass resource, but farmers cannot use these resources effectively. For example, thestraw raw material is burned in a traditional and low-end way; manure is used as farmcompost without doing anything, causing environmental contamination and theresources could not be used efficiently. Developing the biogas fermentation technologywith the straw and dung as raw material is an important means to solve famer energyconsumption and improve rural hygienic conditions. in addition, due to a shortage offossil energy, it need to develop new energy urgently in our country, however, thebiogas as an alternative energy, with very considerable room for development. Thecontent of this subject is the influence factors of anaerobic fermentation of rawmaterials used in rural.In this study, preliminary analysis of the impact of inoculums, temperature,pressure and different raw materials for methane content and biogas production bymonitoring the changes of biogas production, PH value and methane in the fermentationprocess.In this study, there are some research results:(1) Compare with without inoculums, adding30%biogas slurry in the cow dungonly can product gas early, but also can shorten batch fermentation time. After addingthe inoculums, the inoculums need a period of adaptation, then, they can multiplyrapidly, and its gas production and methane content are higher than the cow dungwithout adding inoculums.(2) Gas production potential of the mixture of straw and cow dung is better thandung. Under the constant temperature of35degrees, the total gas production of strawand cow dung mixture is higher than the total gas production of cow dung, but themethane content of mixture has to below the methane content of cow dung. Theporosity of powder Straw is too small to let gas overflow, and it inhibits fermentationsmoothly, so, the peak of gas production has to postpone.(3) Pressure will produce a double effect on gas production and composition. Gasproduction of zero pressure in tank is about two times as much as the gas production incase of gas is bleed four times a day(gas is bleed in morning, noon, afternoon. In case of30degrees，the highest pressure is4.5kpa and the lowest pressure is3.8kpa;at the low temperature of20degrees, the highest pressure is2.9kpa and lowest pressure is2.1kpa).However, the average methane content in case of zero pressure is less than gas is bleedfour times a day.(4) Compared with the temperature of20degrees,35degrees is more suitable foranaerobic fermentation of dairy manure. In the temperature of35degrees, higheractivity of bacteria breed faster, and gas production rate is higher. In contrast, at20degrees, gas production is lower and it has no gas production peak. From the average ofmethane content, there is no difference at20degrees and35degrees, indicating that thetemperature is not the key factor affecting the methane content.(5) H2S content in the biogas is far more than the use of the Specification of20mg/m3, so it need for desulfurization before using the gas.