水稻秸秆NaOH预处理最佳条件的优化

Optimization of NaOH pretreatment conditions for rice straw

水稻秸秆是一种重要的农业生物质资源,但大部分都未经加工利用,造成资源的严重浪费和环境的污染,对其进行预处理发酵制清洁能源是一项节能环保的双赢技术.研究采用稀NaOH溶液对水稻秸秆进行预处理.首先利用单因素试验分别研究预处理温度、NaOH质量浓度、预处理时间和底物质量浓度对总还原糖量的影响,然后在单因素试验的基础上,用正交试验对预处理条件进行优化.结果表明:NaOH质量浓度对水稻秸秆预处理效果影响最大;NaOH预处理的最佳条件是底物质量浓度2.5 g/L、NaOH质量浓度100 g/L、预处理温度120℃和预处理时间48 min,此时总还原糖质量分数最大为464.59 mg/g,为未处理底物的5.09倍,说明NaOH预处理可以显著提高水稻秸秆的糖化率.

Rice straw is an important agricultural biomass resources,however,most of which are without utilization, resulting in a serious waste of resources and environmental pollution,so its pretreatment for fermentation to gaining clean energy is a win-win technique of energy saving and environmental protection.The study used dilute NaOH pretreatment for rice straw.Firstly,single factor experiments were used to study the effect of pretreatment temperature, NaOH concentration,pretreatment time and substrate concentration on the total reducing sugar;then on the basis of the single factor experiment,orthogonal experiments were used to further optimize the NaOH pretreatment conditions. The results showed that NaOH concentration had the most effect on the pretreatment of rice straw.The optimal conditions for alkaline pretreatment were substrate concentration of 2.5 g/L, NaOH concentration of 100 g/L, pretreatment temperature of 120 ℃ and pretreatment time of 48 min.The maximum of total reducing sugar concentration was 464.59 mg/g,which was 5.09 times of that from raw materials,indicating that alkaline pretreatment is necessary to improve the saccharification efficiency of rice straw.