Co-production Of Hydrogen And Methane From Glucose Using Internal Circulation Anaerobic Reactor

With glucose as the matrix, this experiment adopts two-stage IC reactor to simulate energy cascade variation in the process of polysaccharide substance in anaerobic digestion to gain the conclusion that energy utilization rate in sectional type anaerobic digestion reaction system is higher than that in solo reactor. IC reactor is adopted in the experiment to resist high resistance to impact load and gain high disposal rate by hydraulic retention time(HRT) with occupation of a relatively small space, which can be regarded as one of the effective ways in modern organic waste-water treatment. Degradation of glucose matrix is very likely to lead to acidification which will affect functions of the reactor. Therefore, a set of hydrogenand methane-production system is developed to respond to the aforesaid problem. It is made up of a pair of highly effective IC anaerobic reactors which are installed in series, in which one is used as the hydrogen-production reactor to perform the function of pre-treatment and resistance of impact load, and the other one is to further ferment the water from the hydrogen-production reactor to produce methane. Main content of research includes: a. initiation of solo IC reactor and series-installed hydrogen- and methane-production system of IC anaerobic reactor; b. optimization of hydraulic parameter in treating artificial glucose water of solo IC reactor and series-installed hydrogen- and methane-production system of IC anaerobic reactor; c. degradation rate and energy utilization rate of COD in treating artificial glucose water of solo IC reactor and series-installed hydrogen- and methane-production system of IC anaerobic reactor; d. diversity study of prokaryotic microorganism in activated sludge(granule sludge) in solo IC reactor and series-installed hydrogenand methane-production system of IC anaerobic reactor. The study shows:A. In normal temperature, 4g glucose is dissolved in 1L water to perform continuous water domestication, maintaining COD concentration to be between 1000mg/L and 2000mg/L. The two sets of anaerobic digestion reactor are only successfully launched when both degradation rates of COD in the two sets of anaerobic digestion are above 30% and both solo IC reactor and methane-production reactor let out methane, at which time p H of solo reactor, hydrogen-production reactor and methane-production reactor are 8, 5.5 and 7.5 respectively.B.Judging from COD degradation rate, HRT of solo reactor and methane-production reactor is 15 h and hydrogen-production reactor 10 h, when the concentration of inlet COD is 6500mg/L; COD degradation rate reaches its highest when COD degradation rate of series-installed hydrogen- and methane-production system is 77.53%. In this condition, COD degradation rate of solo reactor is 59.09%. However, energy utilization rate of the two sets of anaerobic digestion system is not in its highest. The highest energy utilization rate is gained when inlet COD concentration is 5300mg/L; HRT is 20 h for both reactors; and average energy utilization rate of both hydrogen- and methane-production rate is 6.29%.C.The proportion of butyrate acid in outlet water reached its highest when p H=4.1, which shows that butyric acid-type fermentation is under reaction in hydrogen-production reactor; when p H=7, the proportion of propionic acid in outlet water is lower than that when it is slightly acidic or slightly alkaline in the reactor; the proportion of acetic acid in outlet water of methane-production reactor does not change much as HRT changes, but the proportion of butyric and propioic acid decreases sharply, which symbolizes that there are bacteria in the methane-production reactor to transfer butyric and propionic acid into acetic acid.D.By analyzing through 16 S r RNA, it can arrive that microorganism with higher proportion in activated sludge in hydrogen-production reactor are Firmicutes(72.75%), Proteobacteria(21.92%) and Actinobacteria(4.60%). The one with the highest proportion of all bacterial in methane-production reactor is Firmicutes(66.62%), followed by Proteobacteria(13.86%), Spirochaetes(11.52%), Bacteroidetes(3.22%) and Tenericutes(2.06%). In Archaebacteria, Euryarchaeota(1.29%) is the majority, with other Archaebacteria accounting for 0.76%. Firmicutes(66.8%) maintains the highest proportion in solo IC reactor, followed by Spirochaetes(24%), Bacteroidetes(3%), Proteobacteria(2%) and Actinobacteria(1%), with other bacteria accounting for 1.49%. Euryarchaeota(0.01%) is the majority in Archaebacteria, with other Archaebacteria accounting for 0.01%.