Study On Bio-hydrogen Production From Paulownia Elongate By Photosynthetic Bacteria

In this paper,the process of hydrogen production by photosynthetic organisms of Paulownia elongate was studied.Firstly,the components of Paulownia elongate were determined and analyzed,and the possibility of Paulownia-elongate being used as hydrogen production material for photosynthesis was discussed.Secondly,the hydrogen production experiments of photosynthetic bacteria were carried out with different parts of Paulownia elongate as experimental materials,specific bio-gas production rate,hydrogen production concentration,specific hydrogen production yield,reducing sugar concentration and pH vaule as experimental index were studied.The effects of the initial pH value,substrate concentration and light wavelength on the hydrogen production process of Paulownia biomass photosynthetic organisms were studied.The hydrogen production kinetics was used to analyze the hydrogen production of photosynthetic bacteria.The optimum hydrogen production process parameters of Paulownia biomass photosynthetic organisms were obtained.The hydrogen production process of Paulownia biomass and com straw photosynthetic organisms was compared and analyzed.Paulownia biomass was used as experimental material for hydrogen production by photosynthetic bacteria.(1)The content of cellulose and hemicellulose of Paulownia biomass is higher,including 71.85%of the total fiber of Paulownia stem biomass,72.34%of the total fiber content of Paulownia leaf biomass,17.17%and 17.97%higher than that of corn straw,respectively.After enzymatic hydrolysis,more raw materials can be converted into sugars for hydrogen production by photosynthetic bacteria,thereby increasing hydrogen production.Moreover,the hemicellulose content of Paulownia biomass is higher,especially the hemicellulose content of Paulownia leaves is up to 58.48%,which is easier to be enzymatically hydrolyzed.Therefore,the development of photosynthetic biohydrogen production from Paulownia biomass is an effective way of energy conversion.(2)The optimum technological conditions for hydrogen production from photosynthetic biomass of Paulownia stem are as follows:initial pH value is 8(specific hydrogen production is 54.25 mL/g),substrate concentration is 33.33 g/L(specific hydrogen production is 73.43 mL/g),light wavelength is 492-577 nm(specific hydrogen production is 96.22 mL/g);optimum technological conditions for hydrogen production from photosynthetic biomass of Paulownia leaf are:initial pH value is 7(specific hydrogen production is 41.94 mL/g),substrate concentration is 20 g/L(specific hydrogen production is 34.12 mL/g),light wavelength is 492-577 nm(specific hydrogen production is 61.88 mL/g).Under the influence of different factors and conditions on hydrogen production from photosynthetic biomass of Paulownia stem,the variation of hydrogen production concentration of photosynthetic bacteria was consistent with that of specific gas production rate,that is to say,there was a positive correlation between the two trends.(3)The kinetic analysis of hydrogen production by photosynthetic biomass of Paulownia can be obtained.The hydrogen production potential of Paulownia stem biomass at the optimum initial pH value is 42.60 mL/g,34.29 mL/g at the optimum substrate concentration,and 61.68 mL/g at the optimum light wavelength.The hydrogen production potential of Paulownia leaves biomass at the optimum initial pH value is 56.54 mL/g3 75.15 mL/g at the optimal substrate concentration,and 97.22 mL/g at the optimal light wavelength.(4)By comparing tie results of hydrogen production by photosynthetic biomass from corn straw,it can be concluded that the hydrogen production per unit mass of Paulownia leaf biomass and stem biomass is larger than that of com straw,and the hydrogen production of Paulownia leaf is larger than that of Paulownia stem,which is also consistent with the content of synthetic fiber(paulownia leaf>Paulownia stem>corn straw),and the hemicellulose content of Paulownia biomass.More,especially the half-fiber content of Paulownia leaves is 58.48%,which is easier to enzymatic hydrolysis than cellulose,and is conducive to the metabolic hydrogen production of photosynthetic bacteria.The research on hydrogen production from photosynthetic biomass of Paulownia can provide theoretical basis for further optimization and scale-up,which makes it possible to produce hydrogen efficiently and cheaply.It not only enlarges the application scope of Paulownia,but also broadens the source of substrates for hydrogen production from photosynthetic biomass of Paulownia,and makes up for the gap in the field of new energy research on hydrogen production from photosynthetic biomass of Paulowia.