玉米秸秆纤维素提取工艺优化

Optimization of Cellulose Extraction Process of Corn Straw

[目的]优化提取玉米秸秆纤维素的最佳工艺条件。[方法]采用氢氧化钠-醋酸-亚氯酸钠法提取玉米秸秆纤维素,并用硝酸乙醇法测定纤维素含量。利用单因素试验探讨原料用量、提取时间以及提取温度等因素对产品纤维素含量的影响,并利用正交试验优化工艺条件。[结果]提取玉米秸秆纤维素的最佳工艺条件为:提取过程中,搅拌速度为500 r/min;半纤维素脱除过程中,称取5 g秸秆粉末,NaOH溶液质量分数为9%,提取温度T_1为60℃,提取时间t_1为120 min,将产物洗涤烘干;木质素脱除过程中,取上述产物进行试验,亚氯酸钠用量为1.5 g,醋酸用量为10 m L,提取温度T_2为70℃,提取时间t_2为60 min,将产物洗涤烘干得到纤维素。在此最优工艺条件下,产品纤维素纯度平均可达81.45%,最高可达82.29%,而且经红外分析可发现半纤维素和木质素已基本被去除。[结论]该工艺研究可为玉米秸秆纤维素的批量生产提供理论指导。

[Objective]The research aims to optimize the extraction process of the cellulose from corn stalk.[Method]The cellulose is extracted by the sodium hydroxide and acetic acid and sodium chlorite method,and the cellulose content is determined by the nitrate and ethanol method.Single-factor experiments are conducted to study the effects on the cellulose content of the products,including the amount of raw materials,extraction time,extraction temperature,etc.And orthogonal experiments are used to optimize the process conditions.[Result]The optimum conditions were as follows:During the extraction process,the stirring speed is 500 r/min;in the process of hemicellulose removal,5 g of straw powder was weighed,the mass fraction of NaOH solution was 9%,the extraction temperature T 1 was 60℃,and the extraction time t 1 was 120 min,and the product was washed and dried;in the process of lignin removal,the above products were tested,the amount of sodium chlorite was 1.5 g,the amount of acetic acid was 10 mL,the extraction temperature T 2 was at 70℃,the extraction time t 2 was 60 min,and the product was washed and dried to obtain cellulose.Under the optimum conditions,the purity of cellulose could reach as high as 81.45%on average,up to 82.29%,and by FTIR analysis,hemi-cellulose and lignin had been basically removed.[Conclusion]The process research can provide theoretical guidance for batch production of the cellulose of corn stalk.