化学学报 ›› 2014, Vol. 72 ›› Issue (12): 1223-1227.DOI: 10.6023/A14080576 上一篇    下一篇

研究论文

水热条件下酸催化氧化木质纤维生物质制取乙酸

李江a, 黄耀兵b, 郭庆祥a, 傅尧a   

  1. a. 中国科学技术大学 化学系 安徽省合肥市生物质洁净能源实验室 合肥 230026;
    b. 南京林业大学 化学工程学院 南京 210037
  • 投稿日期:2014-08-08 发布日期:2014-11-03
  • 通讯作者: 傅尧 E-mail:fuyao@ustc.edu.cn
  • 基金资助:

    项目受973计划(2012CB215305,2013CB228103),自然科学基金(21325208,21361140372,21172209),中央高校基本科研业务费专项资金(WK2060190025),教育部高等学校博士学科点专项科研基金(20123402130008),中国科学院(KJCX2-EW-J02)和霍英东教育基金资助.

Production of Acetic Acid from Lignocellulosic Biomass in the Presence of Mineral Acid and Oxygen under Hydrothermal Condition

Li Jianga, Huang Yaobingb, Guo Qingxianga, Fu Yaoa   

  1. a. Anhui Province Key Laboratory of Biomass Clean Energy, Department of Chemistry, University of Science and Technology of China, Hefei 230026;
    b. College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037
  • Received:2014-08-08 Published:2014-11-03
  • Supported by:

    Project supported by the National Basic Research Program of China (2012CB215305, 2013CB228103), the National Natural Science Foundation of China (21325208, 21361140372, 21172209), the Fundamental Research Funds for the Central Universities (WK2060190025), the Specialized Research Fund for the Doctoral Program of Higher Education (20123402130008), Chinese Academy of Sciences (KJCX2-EW-J02) and Fok Ying Tung Education Foundation.

木质纤维基生物质是一类新的能够生产液体燃料和化学品的可再生资源. 本文研究了木质纤维生物质在水热条件下, 以少量无机酸作为酸催化剂, 氧气作为氧化剂(2.0 MPa), 经过"一锅两步法"转化成乙酸的反应. 以玉米秸秆作为反应原料时, 最高可以获得21.3 wt%的乙酸, 占据整个液体产物质量比例的84.6% (选择性). 同时, 将反应推广到玉米芯, 甘蔗渣, 竹子, 杨木和松木等多种生物质原料的转化, 同样取得了较高的乙酸产率. 最后, 我们对木质纤维生物质转化到乙酸的反应过程进行了研究. 研究表明木质纤维生物质中的碳水化合物六碳糖是乙酸的主要来源, 六碳糖经过脱水和水解生成乙酰丙酸中间体, 乙酰丙酸在氧化条件下断裂C—C键生成乙酸.

关键词: 木质纤维生物质, 乙酸, 乙酰丙酸, 氧气, 氧化反应

Nowadays, lignocellulosic biomass is considered as renewable source for the substitute of traditional fossil energy resources. The production of biofuel intermediates such as 5-hydroxymethylfurfural (5-HMF), levulinic acid and γ-valerolactone (GVL), and commercially interesting compounds such as lactic acid and ethylene glycol from biomass has become an important issue for world-wide researchers. In this work, we focused on the conversion of lignocellulosic biomass into acetic acid through a "one-pot two-step" method over inorganic acids in aqueous media. The first step was the hydrolysis of the raw biomass with sulfuric acid at 190 ℃, 1.0 MPa N2 for 1 h. After that, the reaction was changed to 2.0 MPa O2 and allowed to react for another 9 h. HPLC analysis of the result mixture showed that mass yield of acetic acid from corn stover was up to 21.3%, and the selectivity of acetic acid was as high as 84.6% of the total liquid products. Besides, the other lignocellulosic biomass feedstocks such as corn cob, bagasse, bamboo, poplar and pine were also successfully converted into acetic acid in good yields under the optimized reaction condition. In addition, the stability of the catalyst acid was examined, and the recovery of the catalyst acid is about 95%. Thus, to achieve the reuse of the catalyst acid, the addition of extra 10% catalyst acid after each catalytic cycle was needed. Finally, the reaction pathway was explored by using the components of the lignocellulosic biomass feedstocks as the starting materials (sugars etc.). The results showed that the carbohydrates especially hexoses were the main source of acetic acid. It was dehydrated and hydrolyzed into the intermediate levulinic acid, which was then oxidized into acetic acid by C—C bond oxidative cleavage. The current method provided a new access to the bulk acetic acid from sustainable raw biomass.

Key words: lignocellulosic biomass, acetic acid, levulinic acid, oxygen, oxidation