Production Process for Diesel Fuel Components Polyoxymethylene Dimethyl Ethers from Methanol and Formaldehyde Solution
Polyoxymethylene dimethyl ethers (PODEn) as clean diesel additive can improve the combustion efficiency and quality of diesel fuel and alleviate the problem of atmospheric pollution. Considering synthetic routes, PODE production from methanol and formaldehyde is regarded as the most economical and promising synthetic route. However, methanol used for synthesizing PODE can produce water, which causes the loss of active center of catalyst and hydrolysis of PODEn in the production process. Macroporous strong acidic cation exchange resin catalyst was prepared, which has comparative advantages over other common solid acid catalysts in terms of stability and catalytic efficiency for synthesizing PODE. Catalytic reactions were carried out under 353 K, 1 MPa and 3mL·gcat-1·h-1 in a fixed bed reactor. Methanol conversion and PODE3-6 selectivity reached 49.91% and 23.43%, respectively. Catalyst lifetime evaluation showed that resin catalyst retained its catalytic activity for 20 days without significant changes and catalytic activity of completely deactivated resin catalyst can basically return to previous level by simple acid regeneration. The acid exchange capacities of original and deactivated catalyst were 2.5191 and 0.0979 mmol·g-1, respectively, while regenerated catalyst reached 2.0430 mmol·g-1, indicating that the main reason for resin catalyst deactivation is that Brønsted acid sites of original resin catalyst were temporarily replaced by non-hydrogen ion cations. A separation process consisting of extraction and distillation for PODE3-6 product was designed for separation of water and unreacted formaldehyde from reactive mixture and purification of PODE3-6, respectively. The concentration of PODE3-6 in final product can reach up to 97%. These results indicate that the scale-up production of PODE3-6 from methanol and formaldehyde solution is feasible.
Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1474853Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 801
 Haoye Liu, Zhi Wang, Jiaxin Wang, Xin He, Yanyan Zheng, Qiang Tang and Jinfu Wang, “Performance, combustion and emission characteristics of a diesel engine fueled with polyoxymethylene dimethyl ethers (PODE3-4)/ diesel blends,” in Energy, vol. 88, 2015, pp. 793–800.
 Zhihao Ma, Zuohua Huang, Chongxiao Li, Xinbin Wang and Haiyan Miao, “Combustion and emission characteristics of a diesel engine fuelled with diesel–propane blends,” in Fuel, vol. 87, issue. 8-9, 2008, pp. 1711-1717.
 Ludger Lautenschütz, Dorian Oestreich, Philipp Seidenspinner, Ulrich Arnold, Eckhard Dinjus and Jörg Sauer, “Physico-chemical properties and fuel characteristics of oxymethylene dialkyl ethers,” in Fuel, vol. 173, 2016, pp. 129-137.
 Haoye Liu, Zhi Wang, Jun Zhang, Jianxin Wang and Shijin Shuai, “Study on combustion and emission characteristics of Polyoxymethylene Dimethyl Ethers/diesel blends in light-duty and heavy-duty diesel engines,” in Applied Energy, vol. 185, 2017, pp. 1393-1402.
 M Härtl, G Kai, D Pélerin and G Wachtmeister, “Oxymethylene Ether as Potentially CO2-neutral Fuel for Clean Diesel Engines Part 1: Engine Testing,” in MTZ worldwide, vol. 78, issue. 2, 2017, pp. 52-59.
 Qi Zhao, Hui Wang, Zhangfeng Qin, Zhiwei Wu, Jianbing Wu Weibin Fan and Jianguo Wang, “Synthesis of polyoxymethylene dimethyl ethers from methanol and trioxymethylene with molecular sieves as catalysts,” in Journal of Fuel Chemistry and Technology, vol. 39, issue. 12, 2011, pp. 918-923.
 Liang Wang, Wenting Wu, Ting Chen, Qun Chen and Mingyang He, “Ion-exchange resin–catalyzed synthesis of polyoxymethylene dimethyl ethers: a practical and environmentally friendly way to diesel additive,” in Chemical Engineering Communications, vol. 201, issue. 5, 2014, pp. 709-717.
 Huaju Li, Huanling Song, Liwei Chen and Chungu Xia, “Designed SO42−/Fe2O3-SiO2 solid acids for polyoxymethylene dimethyl ethers synthesis: The acid sites control and reaction pathways,” in Applied Catalysis B: Environmental, vol. 165, 2015, pp. 466-476.
 Qin Wu, Min Wang, Yu Hao, Hansheng Li, Yunzhao, and Qingze Jiao, “Synthesis of Polyoxymethylene Dimethyl Ethers Catalyzed by Brønsted Acid Ionic Liquids with Alkanesulfonic Acid Groups,” in Industrial & Engineering Chemistry Research, vol. 53, issue. 42, 2014, pp. 16254-16260.
 Gresham, William F, and R. E. Brooks. “Preparation of polyformals,” US2449469, 1948.
 Moulton, David S, and D. W. Naegeli, “Diesel fuel having improved qualities and method of forming,” in WO, US5746785, 1998.
 Patrini R and Marchionna M, “Liquid mixture consisting of diesel gas oils and oxygenated compounds,” EP1070755, 2001.
 Jianqiang Zhang, Bin Tang, Dingye Fang and Dianhua Liu, “Polyoxymethylene Dimethyl Ethers from Methylal and Trioxane over Modified Cation-Exchange Resin,” in Asian Journal of Chemistry, vol. 26, issue. 10, 2014, pp. 6469-6473.
 Jakob Burger, Markus Siegert, Eckhard Ströfer and Hans Hasse, “Poly(oxymethylene) dimethyl ethers as components of tailored diesel fuel: Properties, synthesis and purification concepts,” in Fuel, vol. 89, issue. 11, 2010, pp. 3315-3319.
 Dorian Oestreich, Ludger Lautenschütz, Ulrich Arnold and Jörg Sauer, “Reaction kinetics and equilibrium parameters for the production of oxymethylene dimethyl ethers (OME) from methanol and formaldehyde,” in Chemical Engineering Science, vol. 163, 2017, pp. 92-104.
 Niklas Schmitz, Eckhard Ströfer, Jakob Burger and Hans Hasse, “Conceptual Design of a Novel Process for the Production of Poly(oxymethylene) Dimethyl Ethers from Formaldehyde and Methanol,” in Industrial & Engineering Chemistry Research, vol. 56, issue. 40, 2017, pp. 11519-11530.
 Fredericwalker, J, Formaldehyde 3rd, Reinhold Publishing Corporation, 1964.
 Riccardo Tesser, Martino Di Serio, Luca Casale, Lucio Sannino, Marianna Ledda, and Elio Santacesaria, “Acid exchange resins deactivation in the esterification of free fatty acids,” in Chemical Engineering Journal, vol. 161, issue. 1-2, 2010, pp. 212-222.