| With the rapid development of world economy and fast growth of thepopulation, it’s no doubt that the increasing demand for energy. The prices of fossilenergy are soaring, sources of oil and electric power increasingly become tense,excessive using of fossil fuels make the environment deteriorative, development andutilization of green energy has become the inevitably trend.Now, numerous scholars of domestic and international have made research anddiscussion on the existing problems of biogas fermentation and biological hydrogenproduction, while there’s few studies of how to use mature biogas anaerobicfermentation and biological hydrogen production technology to achieve hydrogen-richbiogas.The paper is finished with the support of national nonprofit industry (agriculture)research projects-”The study of combination equipment and technology about biogaswidely replace household energy goods”(project number:201303099). Due to theambient temperature and the reaction liquid pH can significantly affect the growth ofbacteria and hydrogen production, the paper set up five kinds of temperature and sixkinds of solution initial pH to respectively to observe the hydrogen volume percentage,total output of hydrogen, methane volume percentage, total output of methane and theaccumulative total volume with fermentation time under the different of twoexperiment factors, to explore the influence of both experiment factors to gasproduction and hydrogen production of straw anaerobic fermentation, it providescertain scientific reference for the scale research of straw anaerobic fermentationtechnology to produce hydrogen-rich biogas. The experiment results show that:(1).The hydrogen obtaining time of straw anaerobic fermentation within50hoursafter starting of fermentation, hydrogen volume percentage in gas production showed adownward trend after the fist rise, hydrogen producing time is consistent withfermented liquid pH falling time.(2).Under the experiment condition of initial pH7.0, the fermentation temperaturerespectively set up25℃,30℃,35℃and40℃, the hydrogen volume percentage was the highest under40℃at the same time, while the methane production and total gasproduction were low under40℃compared with four kinds of cases, the fermentedliquid pH declined to a certain stage without rising, excessively acidize solution madethe gas rate very low in the late of experiment; the total hydrogen productions wassimilar under25℃a nd35℃, but the total gas production and methane production werehigher under35℃,the total hydrogen production was about seventy percent ofcondition under40℃,the fermented liquid could rise to stable stage for producing gasafter acidification in the early of fermentation; the hydrogen production, methaneproduction and total gas production were lower than the other cases. Therefore,35℃isconsidered the optimum technological conditions for anaerobic fermentation to achievehydrogen-rich biogas.(3).Under the experiment condition of35℃, the fermentation initial pHrespectively set up5.65,5.90,6.53,7.53,8.14,8.93,the hydrogen volume and totalhydrogen production were highest under the initial pH5.65and5.90,but thefermented liquid pH declined to5.30in ninetieth hour without rising, excessivelyacidize solution made the gas rate slow, it even stopped producing gas in the late ofexperiment, the methane volume, what’s more,total methane production and total gasproduction were the minimum under pH5.65and5.90; the methane volumepercentage and total methane production were similar under initial pH7.53and8.14and higher than other cases，but the hydrogen volume percentage under pH8.14ishigher than pH7.53,the total hydrogen production is twice than pH7.53.so initial pH8.14is considered the optimum technological conditions for anaerobic fermentation toachieve hydrogen-rich biogas.(4).In the process of fermentation the hydrogen volume percentage could achieve4.5%under initial8.14and35℃constant temperature, it got65ml hydrogen in280hours, the gas production could achieve2020mlin one day. |
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