汽爆玉米秸秆酶解时表观酶活及物料理化性质的变化  

Changes of apparent enzymatic activities and physical and chemical properties of steam-exploded corn stover during enzymatic hydrolysis

作　　者：张霞[1,2] 李红伟[1,3] 马晓建[1] 

机构地区：[1]郑州大学化工与能源学院,郑州450001 [2]华北水利水电学院,郑州450011 [3]浙江闰土股份有限公司,上虞312300

出　　处：《农业工程学报》2013年第11期203-209,共7页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家十一五科技支撑计划(2007BAD66B04)

摘　　要：为推动汽爆玉米秸秆生产丁醇的工业化进程,从工程实际出发,针对汽爆玉米秸秆酶解过程进行研究,考察酶解液糖浓度、纤维素酶表观酶活以及搅拌器搅拌功率的变化,并利用显微镜、电镜、X-ray、以及粒度分布仪对酶解反应过程中物料物理化学性质的改变进行表征。结果表明:随着酶解反应的进行,酶解液糖浓度从初始的0持续增加到56.25g/L,搅拌功率持续降低,由反应初期的32.3W降低至反应后期的5.2W,且都是在1h内变化最快;纤维素酶表观酶活则表现为先降低后增加,然后再降低的趋势;在酶解过程中固体颗粒粒度呈现降低的趋势,比表面积逐渐增加,结晶度和微晶尺寸也有所降低,颗粒内部空腔增多。该研究为秸秆丁醇工业化提供参考。Based on engineering practice, the sugar concentration, power and apparent enzymatic activities change of enzymolysis suspension in enzymolysis process of steam-exploded corn stover （SECS） were studied to promote the industrialization process of corn stover producing butanol. At the same time, the changes of SECS physical and chemical properties during enzymatic hydrolysis were studied by biological microscope, laser scattering particle size distribution analysis （LSPSDA）, X-ray diffraction （XRD）, and scanning electron microscopy （SEM）. Enzymatic hydrolysis was performed in a reactor with standard commercial cellulase as the enzyme. Enzymatic hydrolysis took place at 50℃, 100 r/min （four oblique leaves T agitator）, enzyme loading of 60 IU/g corn stover, a solid：liquid ratio 3：10, and 48 h duration. Before the enzyme was added, the pH of the residues was adjusted to 4.8 with sodium hydroxide. After enzymatic hydrolysis the samples were taken from the reactor and centrifuged, and the supernatant phase was collected and analyzed for sugar concentrations, cellulase apparent enzymatic activities, and the physical and chemical properties of SECS. Sugar concentrations were tested by 3,5-Dinitrosalicylicacid（DNS）. Cellulase apparent enzymatic activities were determined by the filter-paper method. Scanning electron microscopy and X-ray diffraction analysis were conducted. The results show： In the first reaction, the sugar concentration in the enzymatic hydrolysis liquid increased very quickly, especially in the first hour. The change in sugar concentration was not very clear later in the hydrolysis reaction due to such factors as substrate loss, changes in substrate properties, cellulose inactivation, decreasing cellulose synergy, and so on. The sugar concentration after enzymatic hydrolysis 48 h was 56.25 g/L. The stirring power decreased during enzymatic hydrolysis and declined most quickly after one hour of enzymatic hydrolysis, then began to decline more slowly. The apparent enzymatic a

关 键 词：酶 水解 秸秆 丁醇 表观酶活 蒸汽爆破 

分 类 号：TQ353.2[化学工程]