慈竹机械浆(RMP)氨法预处理工艺

Effect of Ammonia Pretreatment on Enzymatic Hydrolysis of Bamboo(Sinocalamus affinis) Refiner Mechanical Pulp(RMP)

研究了在氨水中添加少量KOH或K3PO4预处理慈竹机械浆(RMP)的工艺。考察了预处理条件对酶解还原糖产率的影响。单因素实验得到氨水加KOH最佳预处理条件为:预处理温度120℃、固液比〔即1 g绝干浆加入液体的体积(mL),下同〕1∶6、时间3.5 h、氨水用量70%(即氨水质量占绝干浆质量的百分数,下同)、KOH用量5%(即KOH质量占绝干浆质量的百分数,下同)。在此最佳条件下,慈竹RMP的纤维素保留率为90.66%,半纤维素保留率为92.90%,木质素脱除率为41.05%;在pH=4.8、加酶量20 FPU/g预处理后底物、反应温度50℃的条件下酶解24 h,还原糖产率为23.95%,纤维素转化率为44.61%。虽然氨水加K3 PO4预处理酶解纤维素转化率可达56.95%,但是纤维素保留率仅为74.59%,与氨水加KOH相比,纤维素损失较大。

The effect of the pretreatment conditions on enzymatic digestibility was discussed, with bamboo（ Sinocalamus affinis） refiner mechanical pulp（RMP） as the feedstock soaking in two different solutions, ammonia and potassium hydroxide, and ammonia and potassium phosphate. The optimum pretreatment conditions of ammonia and potassium hydroxide were ascertained as follows： reaction temperature 120 ℃ ,per gram solid add liquid 6 mL,pretreatment time 3.5 h, ammonia charge 70% （g/g oven dry） , potassium hydroxide charge 5 % （ibid）. Under such optimum conditions, the recovery ratio of cellulose, hemicelluloses and the delignification ratio can reach 90. 66%, 92. 90 % and 41.05 %, respectively. The reducing sugar yield and conversion yield of cellulose can attain 23.95% and 44.61% respectively under the condition of per gram of pretreatment feedstock loaded with 20 FPU after enzymatic hydrolysis for 24 h in acetic acid sodium buffer solution of pH 4. 8 and reaction temperature 50 ℃. The conversion yield of cellulose can attain 56.95%, but the recovery ratio of cellulose is only 74. 59% with the pretreatment method of ammonia and ootassium ohosohate. The loss of the cellulose recovery is greater than that with the hydroxide.