The Explore Of The Chemical Pretreatment Technology Of Stalk And The Microbial Degradation Factors

This research is about the chemical pretreatment of the crop straw and the microbial degradation of straw cellulose, the chemical pretreatment can make lignin remove and improve the cellulose content that in favor of the microbial degradation of the straw cellulose .It's discovered that the dilute NaOH solution have better pretreatment effect than the dilute H₂SO₄ solution through the chemical pretreatment experiment.The cellulose content of 40 mesh straw can get up to 69.2%, the upgrade rate of cellulose is 105.71% and the lignin removal rate is 94.7% under the pretreatment conditions of the concentration of 3% NaOH solution, the solid-to-liquid ratio of 1:20, the temperature of 108¹15℃and 1 hour.The cellulose content of 60 mesh straw can get up to 64.71%, the upgrade rate of cellulose is 109.08% and the lignin removal rate is 83.66% under the pretreatment conditions of the concentration of 4% NaOH solution, the solid-to-liquid ratio of 1:20, the temperature of 115¹21℃and 1 hour.The straw that there is more cellulose content after chemical pretreatment by the experiment screening is used to the cellulosic flora degradation experiment.The conclusion is produced by the experiment of microbial flora degradation and sugar test.The glucose content of the degradate system have the highest value until the fourth day when the 5# microbial flora inoculated into the 25ml-6% system at 30℃for pretreated straw in 40 mesh, then the sugar yield is 22.690 mg·g^-1.However, the glucose content of the degradate system have the highest value until the fourth day when the 6# microbial flora inoculated under the same conditions for pretreated straw in 40 mesh, then the sugar yield is 26.563 mg·g^-1.The glucose content of the degradate system have the highest value until the sixth day when the 5# microbial flora inoculated into the 25ml-6% system at 30℃for pretreated straw in 60 mesh, then the sugar yield is 30.935 mg·g^-1.However, the glucose content of the degradate system have the highest value until the second day when the 6# microbial flora inoculated under the same conditions for pretreated straw in 60 mesh, then the sugar yield is 30.028 mg·g^-1.The degradability of 6# microbial flora is better than 5# in the 40 mesh straw degradation experiment and sugar test,but the situation is opposite in the 60 mesh straw degradation experiment,however the optimal degradation temperature of two kind of microbial flora is both 30℃.