| Driven by the increasing population and global economy, the energy consumption is becoming a critical limitation to the development to all the countries. Renewable energy, especially bio-energy is becoming well accepted. China, as the one of the largest agricultural product body, has the most abundant amount of straw resource. An estimation result showed the collectively straw is approximately800Mt out of a total production of900Mt. It is of much value to convert such a large quantity of agricultural waste into clean energy.Biogas solution has showed a great potential in China. A totally41million of household used biogas plants will be constructed until the end of2010. However, some problems about the management of the plants also have been observed and proposed. As well as some typical problems during manipulating manure-straw single phase fermentation. Additionally, there is always bubbles, tiny or big, been observed from the product chamber, from which the slurry will be taken out.So, enzymatic pre-treatment and two-phase anaerobic digestion using rice straw/grass with recirculation was designed in this study. And the biogas emission from the product chamber was also been tested to obtain the productivity. The construction of future "hydraulic" biogas plants will benefit from the results.Test with fresh pig manure after oxidation pretreatment as the raw materials of biogas fermentation, inoculation sludge TS concentration of30%, while preparing for the cellulase-treated straw extract and the use of biogas slurry and straw, and explore the fiber in the experiment, the celluciferase can play an active role in, and also discusses the different amount of liquid replacement, concentration of displacement and replacement frequency of the different effects of the so-called replacement is to remove part of the liquid then add the same amount of liquid. The test results showed that soaking the role of methanogenic biogas slurry handling is slightly better than soaking the enzyme treatment, a large number of replacement (2L/replacement rate of57.1%) of the cumulative methane production was significantly greater than the other groups (1L/feed rate of28.6%),3d replacement after18d cumulative gas production is also greater than the cumulative gas production of7days under the same conditions replacement time after18d. The replacement of the COD concentration test, within a certain range of the high concentrations of replacement on the production of CH4remarkable role in the COD concentration of the high gradient in the replacement test, the replacement fluid COD concentration of2000mg/L gas production.In the experimental test of biogas emission from the product chamber, a average production of6L/m3·d of a biogas reactor with a volume of8m3was verified. The peak production from the product chamber (143L) accounted for19%of that of the main digester with the same day (770L). Accumulated production (373L) represented9.2%out of the main digester (4069L) within6days. A gas constitution with an average methane content of the gas was70%, CO2and a small amount of H2S also provided a strong evidence that the gas was a typical biogas.The study suggested some improvements to the normal biogas reactors widely used in the rural places in China by researching a two-phase anaerobic digestion process with rice straw extracts. The economy and possibility was verified. Recirculation for increasing the HRT of the digester was introduced and proved to be practical. For the first time domestically, the biogas emission from the product chamber was brought and experimentally studied. The results showed that the problem with normal product chamber has been existing from the very beginning of the building up of theory and techniques. All this study will attribute to the research and development of the biogas production using undergrounded biogas digester in China. |
PDF Full Text Request