催化学报

催化学报 ›› 2012, Vol. 33 ›› Issue (8): 1389-1394.DOI: 10.3724/SP.J.1088.2012.20337

• 研究论文 • 上一篇    下一篇

HZSM-5 分子筛用于合成聚甲醛二甲基醚

高晓晨a, 杨为民b, 刘志成, 高焕新   

  1. 中国石油化工股份有限公司上海石油化工研究院, 上海 201208
  • 收稿日期:2012-03-20 修回日期:2012-05-20 出版日期:2012-08-01 发布日期:2012-08-01

Catalytic Performance of HZSM-5 Molecular Sieve for Synthesis of Polyoxymethylene Dimethyl Ethers

GAO Xiaochena, YANG Weiminb, LIU Zhicheng, GAO Huanxin   

  1. Shanghai Research Institute of Petrochemical Technology, SINOPEC, Shanghai 201208, China
  • Received:2012-03-20 Revised:2012-05-20 Online:2012-08-01 Published:2012-08-01

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摘要： 以磷酸二氢铵为前驱体, 使用浸渍法制备了一系列不同磷含量改性的 HZSM-5 分子筛, 并结合 X 射线衍射、N2 吸附和氨程序升温脱附等表征结果探讨了催化剂硅/铝比、粒径尺寸、晶体结构、孔结构及表面酸性对其催化甲醇和三聚甲缩反应生成聚甲醛二甲基醚 (PODEn) 反应性能的影响, 同时与商业催化剂进行了比较. 结果表明, 硅铝比为 50, 粒径尺寸为 5 μm, P2O5 含量较低 (0~6%) 的 HZSM-5 分子筛表现出较高的催化活性和 PODEn 选择性. 在 130 ℃, 原料甲醇和三聚甲醛的质量比为 2:1 的优化条件下反应时, 三聚甲醛转化率可达到 95.2%, PODEn (n = 2~5) 的选择性为 62.9%, 略好于商业催化剂.

关键词: 聚甲醛二甲基醚, 甲醇, 三聚甲醛, HZSM-5 分子筛, 燃料添加剂

Abstract: Polyoxymethylene dimethyl ethers (PODEn) were synthesized using methanol (MeOH) and trioxymethylene (TRI) as raw materials. Catalytic performance of acidic molecular sieve HZSM-5 catalyst and PODEn selectivity were found to be strongly dependent on silica/alumina ratio, particle size, phosphorus modified and etc. A series of HZSM-5 zeolite samples modified with various contents of phosphorus were prepared by impregnation with an ammonium dihydrogen phosphate. The crystal structure, pore structure, and surface acidity of the catalyst were studied by various characterization techniques such as X-ray diffraction, N2-adsorption, and temperature-programmed desorption of NH3. Under the mild reaction conditions of 130 °C and raw materials mass ratio MeOH/TRI = 2, methanol conversion and the PODEn (n = 2–5) selectivity were 95.2% and 62.9%, respectively, by using the Pd-modified HZSM-5 catalyst with the optimum conditions (molar ratio of Si to Al was 50, particle size was 5 μm, low-P2O5 content (w = 0–6%) for the preparation). Catalytic performance of HZSM-5 was higher than that of reference commercial catalysts.

Key words: polyoxymethylene dimethyl ether, methanol, trioxymethylene, HZSM-5 zeolite, fuel additive