超临界二氧化碳及超声预处理促进玉米芯水解制备还原糖研究

以玉米芯为原料,使用超临界二氧化碳及超声预处理后,再用稀酸水解制备还原糖。重点考察了预处理温度、原料含水量以及超声作用时间对还原糖产率的影响。结果表明,超临界二氧化碳预处理最佳条件为:100℃,原料含水量 50%、 30 min、 15 MPa;超声预处理最佳条件为:59 kHz、 90 W、 20 min;采用质量分数为 1% 稀硫酸溶液对预处理样品进行水解,水解温度 160℃、 时间 40 min、 液固比50:1,以评价预处理的效果,两种预处理条件下对应的最大还原糖产率分别为 39.5% 和 38.4%,相比空白样品分别提高13.3和12.2个百分点。

Preparation of Reducing Sugars via Accelerated Hydrolysis of Corncob by Supercritical Carbon-dioxide and Ultrasonic Pretreatment

Reducing sugars can be derived from biomass hydrolysis. The corncob hydrolysis was conducted after supercritical carbon dioxide pretreatment and ultrasonic pretreatment. The effects of pretreatment temperature, moisture content, temperature and time of ultrasonic on the yield of the reducing sugars were emphasized. The result shows showed that the optimum conditions of corncob supercritical carbon dioxide pretreatment were 100~C, 50 % moisture content, 30 min and 15 MPa. The optimum conditions of corncob ultrasonic pretreatment were 59 kHz,90 W and 20 min. The pretreated corncob was hydrolysised with 1% dilute sulphuric acid under the condition of 160℃, 40 min and liquid to solid ratio of 50： 1. The highest yield of reducing sugars is 39.5 % and 38.4 % , respectively. Compared with the control sample, the yield of the reducing sugars was increased by 13.3 and 12.2 percent point, respectively.