Study On The Technology Of Coordinated Pretreatment By Corn Straw Used For Biological Hydrogen Production

At present, the majority of crop straw in China is not reasonable exploitation and utilization, causing serious waste of resources and environmental pollution. While the rich cellulose resources can be used to produce hydrogen by direct or indirect route. Therefore, in our country the research and development of crop straw cellulose conversion technology used for hydrogen production has a significant advantage and is meaningful to solve the problem of energy shortage and environmental protection. The road to explorate the photosynthetic hydrogen production is still very long limited by factors of high cost of Cellulose degradation and low hydrogen production efficiency. Cellulomonas flavigena can produce cellulase to decompose cellulose of crop straw,producing sugar and small molecule acid which can be used for hydrogen production by photosynthetic bacteria. The pretreatment experiment is divided into two stages.Firstly,use the dilute sulfuric acid to pretreatment of corn straw,and then adujust the p H value,,using the cellulase produced by Cellulomonas flavigena,continued to decompose corn straw.Finally, photosynthetic bacteria use the liquid to produce hydrogen production.The research has important reference value for further study on pretreatment technology of the straw and photosynthetic hydrogen technology. The results show that:(1) First of all, through the single factor experiment design, process conditions of acid treatment stage is optimized. Conclusion: Reducing sugar accumulation increased with sulfuric acid concentration increased, the extending of treatment time, temperature rising. The highest reducing sugar accumulation was obtained when the solid-liquid ratio was 1:10, the concentration of sulfuric acid was 2%, pretreatment time was 60 min, temperature of 120 degrees.The highest reducing sugar accumulation was 888.29 mg.(2)At the biological pretreatment stage,Cellulomonas flavigena was selected as Cellulose degradation bacteria, belongs to Cellulomonas.Cellulomonas flavigena in peptone beef extract agar colonies are usually raised, pale yellow, which belongs to the energy heterotrophic bacteria, can be used for fermentation and produce a variety of cellulase. The strongest enzyme activity is obtained when the corn straw fermentation of 60 h.(3) The process conditions include solid-liquid,p H value and temperature of Cellulomonas flavigena degradation of corn straw cellulose were optimized. Draws the following conclusion, the highest reducing sugar accumulation was 3.26g/L when corn straw and bacteria liquid solid-liquid ratio was 15%, p H value was 6, temperature was 25℃.(4) Through the single factor experiment design, the corn straw chemical- Biological synergistic pretreatment conditions were optimized, draws the conclusion: after corn straw by sulfuric acid treatment, then the biological pretreatment. Corn straw synergistic pretreatment time was reduced to 12 days, the content of reducing sugar increased greatly.(5) Through orthogonal experimental design, the combined pretreatment process conditions of corn stalk were optimized, the conclusion:the optimum process conditions for chemical pretreatment of sulfuric acid concentration in the 8% stage, the processing time for 150 min, temperature 121 C, biological pretreatment of the initial p H value is 5, Cellulomonas flavigena inoculation quantity for the 30 ml. Reducing sugar concentration is highest, the highest for the 1520 mg, the hydrogen yield up to 640 ml.