Enzymatic Saccharification Of Phragmites Australis Biomass In Ethanol Manufacturing

Lignocellulosic biomass is a abundantly available resource, and its bioconversion to fuel ethanol is significant in the sustaining development of our economy. In this paper, harvesting time and enzymatic saccharification of reed were both studied, which was supposed to provide references for enthanol producting.(1) The weight and other parameters of reed were increased in harvesting time. From July to September, plant fiber yeild increased with its, the average of maximum was 90.33 g in mid to late Sep., plant hemicellulose yeild were 84.98 g at the same time. The lignin content was changed from 20% to 25%. Conside the effect of weight parameter, plant hemicellulose and cellulose production, harvesting time of reed was decided in mid to late Sep. for alcohol production.(2) Pretreatment with dilute acid and steam explosion united way was better than others, hydrolysis rate was 35.5%, and total sugar of saccharification was 41.37 mg/mL, compared with be pretreatments by dilute acid and steam explosion only. The efficiency of total sugar with saccharification was increased 39.2% and 33.8%, respectively. Pretreated by this united technique could hydrolysising hemicellulose effective, effectinging the structure of cellulose with steam-explosion, increasing the surface with cellulase and xylanase, enhancing the saccharification efficiency.(3) The mathematical model of total sugar concentration was infected by concentration of sulfuric acid pretreatment (A),volume of Tween-80 (B) and MnSO₄ (C): Sqrt(R₁)=44.25-4.76×A-0.15×B +1.96×C+0.6×A×B+0.18×A×C-0.44×B×C-7.5×A²-0.62×B²-0.85×C². As the proportional error between experimental data and theoretical value was 0.63%, the model was fitted in application.(4) The result of optimizing was: Pretreated by soaking in 1.0% H₂SO₄, and then steam explosion was performed in a holding-time of 120 s and a pressure of 2.0 MPa. Subsequently, those pretreated materials were saccharified through enzymeolysis. The following were considered to fit the enzymatic saccharication best, volume of 1 mL cellulase, xylanase 0.5 g, Tween-80 0.6 mL, MnSO₄ 0.2 g, 45℃for 10 h and at pH 5.0, a speed of 180 r/m, the total sugar yield was reached 46.6 g/L. Enzymatic saccharification with optimal conditions from 0 hour to 34 hour. The cellulose contents were decreased, the hemicellulose and lignin contents showed an upward trend in the corresponding.Glucose and xylose were higher in the liquid of enzymatic saccharification.Contents of arabinose, cellobiose and galactose were very low, and unchanged in the whole reaction time.