化工学报 ›› 2015, Vol. 66 ›› Issue (8): 3113-3119.DOI: 10.11949/j.issn.0438-1157.20150813

• 催化、动力学与反应器 • 上一篇    下一篇

改性膨润土催化麻疯树油酯交换反应动力学及生物柴油纯化

胡雪玲1, 韦藤幼1, 吴炼1, 张寒冰1,2, 童张法1   

  1. 1 广西大学化学化工学院, 广西 南宁 530004;
    2 广西大学环境学院, 广西 南宁 530004
  • 收稿日期:2015-06-03 修回日期:2015-06-10 出版日期:2015-08-05 发布日期:2015-08-05
  • 通讯作者: 童张法
  • 基金资助:

    国家自然科学基金项目(21076046,21166004);广西教育厅科研资助项目(LX2014005)。

Kinetics of jatropha oil transesterification catalyzed by modified bentonite and biodiesel purification

HU Xueling1, WEI Tengyou1, WU Lian1, ZHANG Hanbing1,2, TONG Zhangfa1   

  1. 1 School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, Guangxi, China;
    2 School of Environment, Guangxi University, Nanning 530004, Guangxi, China
  • Received:2015-06-03 Revised:2015-06-10 Online:2015-08-05 Published:2015-08-05
  • Supported by:

    supported by the National Natural Science Foundation of China (21076046,21166004) and the Science Foundation of Guangxi Educational Department (LX2014005).

摘要:

用氢氧化钙和氢氧化钠联合改性活性白土制备了膨润土固体碱催化剂,并用于麻疯树油和甲醇酯交换反应合成生物柴油。主要目的是研究酯交换反应的动力学及纯化反应获得的粗生物柴油使其达到相关国际标准。首先在消除内外扩散的条件下,测定323.15~338.15 K温度范围内的反应动力学数据,并用拟均相模型进行拟合。在室温下使用膨润土为吸附剂对粗生物柴油进行纯化,以移除游离甘油为目标,考察吸附剂用量和吸附时间的影响,以获得适宜纯化条件。结果表明,膨润土固体碱催化剂有较高的活性和稳定性,所得生物柴油粗产品质量较好;反应过程符合拟一级反应动力学机理,活化能67.87 kJ·mol-1;在3%(质量分数)的膨润土用量,室温吸附30 min的条件下,纯化后的生物柴油符合欧洲标准(EN 14214)且产品收率超过96%。

关键词: 催化, 动力学, 生物柴油, 固体碱, 酯交换, 膨润土, 纯化

Abstract:

A bentonite catalyst was prepared using acid-treated bentonite modified by calcium hydroxide and sodium hydroxide with wet method, and it was applied in the transesterification of jatropha oil with methanol to form biodiesel. Firstly, the kinetics of this transesterification reaction was studied in the temperature range of 323.15—338.15 K after eliminating both inner and outer diffusion effects. Then, the crude biodiesel from the transesterification was purified using the adsorption of natural bentonite at room temperature, and the effects of bentonite dosage as well as adsorption time on the removal of free glycerin were investigated. The results showed that the conversion of jatropha oil to biodiesel on the prepared catalyst reached 96.7% under the optimized conditions. And the transesterification can be well described using the pseudo-first-order kinetic model with the activation energy of 67.87 kJ·mol-1. The purified product could meet the requirements of European Standard for biodiesel fuel (EN 14214) with the yield of biodiesel over 96%, when the purification process was performed with a bentonite dosage of 3% (mass) and reaction time of 30 min.

Key words: catalysis, kinetics, biodiesel, solid base, transesterification, bentonite, purification

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