基于响应面法的玉米秸秆纳晶纤维素酸法制备工艺优化

Optimizing acid hydrolysis preparation technology of corn stalk nanocrystalline cellulosevia response surface method

以农业废弃物玉米秸秆纤维素为原料,基于Box-Behnken试验设计,采用响应面法探讨了硫酸质量分数、水解温度和水解时间对玉米秸秆纳晶纤维素得率的影响,建立二次多项式回归模型,并对酸水解制备工艺参数进行了优化。结果表明,玉米秸秆纳晶纤维素适宜的酸水解制备工艺条件为硫酸质量分数60%、水解温度57℃和水解时间80 min,该条件下纳晶纤维素的得率达到66.85%。制备的玉米秸秆纳晶纤维素主要呈棒状。研究表明,试验值与模型优化模拟值基本一致,表明优化模型有较好的可靠性。

In this paper, we would like to introduce a new approach to optimizing the acid hydrolysis process of corn stalk nanocrystalline cellulose v/a the surface response method. As is known, nanocrys- talline cellulose enjoys a great deal of marvelous behaviors, which make it widely used in the field of food processing, papermaking, en- vironmental protection and renewable medical materials, and so on. However, due to the high cost of nanocrystalline cellulose prepara- tion, its industrial application remains severely restrained. As a major farming waste, corn stalk contains a lot of cellulose, lignin, hemieel- lulose and other natural polymer substances. If the cellulose of corn stalk could be extracted successfully with nanoerystalline cellulose, it would be possible for the industry to gain the huge economic and en- vironmental benefits to enrich our daily life and industrial production. It is just for this splendid need that we have made great endeavors to explore the potential for utilizing the corn stalk cellulose and improve on the processing condition for the future development. Based on the Box-Behnken design, we have studied and chosen the three key fac- tors on the yield of nanocrystalline cellulose, that is, the sulfuric acid concentration, hydrolytic temperature and hydrolytic time. In addi- tion, we have also managed to optimize the processing condition of corn stalk nanocrystaUine cellulose via the acid hydrolysis and re- sponse surface and worked out a mathematical model of the second or- der quadratic equation for the yield of nanocrystalline cellulose. As a result, our analysis and experiment prove that the regression model is fit for the relation among the corn stalk nanocrystalline cellulose, the sulfuric acid concentration, hydrolytic temperature and the hydrolytic time. And, last of all, we have optimized such technological parame- ters as the maintenance sulfuric acid mass fraction （60%）, the hy- drolytic temperature （57 ℃ ）, the hydrolytic time （80min）, then the yield of corn stalk nanocrystalhne cellulose can achieve 66.85%. What is more, the prepared nanocrystalline cellulose of corn stalk turns out to be mainly rod-shaped. The optimal test processing condi- tion of the cellulose v/a the acid hydrolysis helps to significantly raise the yield of the product, thus, enabling to reduce the cost for prepar- ing it remarkably.