Study On The Effect Of Temperature On The Characteristics Of Anaerobic Digestion

Anaerobic digestion took on the energy, economy, zoology and society's benefit distinctly, and has been applied abroad on the innocuity dealing with castoff and resource utilize, for example, crop straw, the dejecta of human or livestock and so on. There were many factors influence on the process of anaerobic digestion, and the reaction mechanism was very complex. Temperature is one of the main factors. Since the 30's of 20 century, Buswell and other scholars had study on the relationship by the numbers between the anaerobic digestion animalcule and the condition of producing biogas, and discovered that temperature is the most important in the process of the anaerobic digestion. Whether the temperature is proper that decided the success or fail of the anaerobic digestion directly. Up to now, temperature was the only one which had no assured data and record on the influence of producing biogas capacity through anaerobic digestion and the material fermented time. Firedamp could fermented and produced gas at the 10～60℃in theory. A lot of region coached base on the theory value in practice operation, but received little effect, and wasted the manpower, material resources and financial. The study is to explore on the rule that the influence of ferment temperature to the producing gas capacity through anaerobic digestion and biogas producing speed in the process of anaerobic digestion, seeking ferment temperature that is the best of all, the purpose of realizing the controlling the firedamp ferment and providing the scientific according as estimate in order region of China, offering theory and technology support on settling the problem of environments polluting in the using inconsequence the agriculture castoff and the father countermeasure on the headstream of the agriculture pollution.This experimentation carried through batch test using ferment equipment of constant temperature could be controlling and designed by ourselves, with the ferment material of crop straw ( wheat-stalk, rice-stalk, corn-stalk) and the dejecta (of pig, cattle, chicken and man), and the fundus-thing of normal temperature oxygen-detested digesting pool served as the inoculate substance, with the condition of the total solid mass fraction is 8%. The influence of different ferment temperature on the speed of producing gas, the producing tolerance and the ferment time between 25～40℃with 5℃as a temperature grads. The results were analyzed with the method of excessive factor regress by SAS software, and the best excellent regress equation was found, the most proper ferment temperature of different ferment material was educed and the correspond digest time and the most tolerance produced by the substance cumulate were found at the same time.Main conclusions:1.The experimentation results were analyzed with the method of excessive factor regress by SAS software, and the regress equation about the tolerance produced by the substance cumulate, temperature and the time was found. It could be seen that the regress modeling reached the marked level from the square difference analyzing results of the regress step by step.2.The different ferment material could produce biogas normally at the 4 temperature from the experimentation results. However, the most producing gas speed and the most cumulated producing tolerance of the anaerobic digestion materials. The experimentation indicated that the producing speed anaerobic digestion by the dejecta and the cumulated producing tolerance would not rise along with the temperature hoisted.3.It could be known that the optimized time required by anaerobic digestion mixed between the dejecta and the crop straw, is all over 30℃,and the material could ferment sufficiently in about 60 days.4.The peak value arisen time of the producing biogas speed by anaerobic digestion and the ferment cycle would shorten along with the temperature hoist in a certainty temperature scope, and the peak value and the producing tolerance would also increase along to the temperature rise.5. Pretreatment with the ferment materials before the anaerobic digestion was benefit for acidifications hydrolyze of the ferment materiel, in order to enhance the efficiency of the maintaining anaerobic digestion and abridge the ferment time.6.Experimental results and regression analysis show that temperature and time of anaerobic digestion have not inevitable relation,in another way ,the higher temperature doesn't mean anaerobic digestion needs less time。7.Regression results show that the optimal temperature of affecting wheat straw,rice straw and maize straw fermentation are already exceeding the experiment.