碱法分离回收水稻秸秆中木质素

中国是一个农业大国，拥有丰富的秸秆。农作物秸秆中的木质素是一种天然可再生芳香高聚物，具有良好应用价值。研究秸秆中木质素的分离回收方法对秸秆资源的有效利用有重大意义。目前木质素的分离方法多样化，不同处理方法对木质素的分离具有较大的影响。本文结合木质素与某些金属离子螯合呈可溶性盐这一特点，采用碱法与亚硫酸钠法复合处理秸秆，提出一种简单新型分离秸秆中木质素的方法。通过正交试验研究了氢氧化钠、亚硫酸钠、硫酸锌添加量及pH对木质素分离的影响，并找出一种最佳的木质素分离方案。研究表明氢氧化钠添加量及pH对木质素分离影响显著，随着氢氧化钠浓度及pH的增加，木质素的分离效果增加。其最佳方案中木质素的提取率最高可达97.14%，冻干后木质素回收率为88.97%，制备的木质素磺酸锌盐中锌质量分数为2.4%。本研究为秸秆中木质素的分离回收及秸秆有效利用提供了一种简单的新途径。

Study on separation and recovery of rice straw lignin via alkali method

China is a one of the greatest agriculture nations,and produces huge amounts of straw resources every year.The lignin of straw is a kind of natural renewable aromatic polymers with broad application prospects.Thus,studies on the effective separation and retrieval of lignin are of great significance.Nowadays methods on lignin separation are diverse and different approaches have great different influences on separating and retrieving lignin.In consideration of soluble salts derived from chelation of lignin and certain metals,we put forward a new proposal to use alkali plus sulphite to separate and retrieve lignin from rice straw.Orthogonal test was used to study the effects of sodium hydroxide,sodium sulfite,zinc sulfate and pH values on lignin separation.Thereafter,the optimum strategy of lignin retrieval was found.Results showed that sodium hydroxide application rates and pH values had significant impacts on lignin separation.The recovery of lignin compounds increased with sodium hydroxide application rates and pH values.The greatest lignin recovery reached 97.14% and 88.97% lignin was retrieved after lyophilization.The percentage of zinc percentage in the final zinc lignosulfonate amounted to 2.4%.This study provides a new approach to separate lignin from straw and realize straw utilization in an effective way.