Continuous Anhydrous Synthesis of Oxymethylene Dimethyl Ethers by Reaction of Dimethyl Ether with Molecular Formaldehyde
Source abstract
Abstract
Abstract A novel gaseous synthesis route to oxymethylene dimethyl ethers (OMEn, n = 3−5) starting from CO2 and green H2 by using molecular formaldehyde (FA) and dimethyl ether (DME) is presented. The anhydrous reaction runs in a pressure free, gaseous, and continuous reaction setup. Hetero‐geneous cata‐lysts including zeolites and ion exchange resins (IER) are investigated, if they catalyze this reaction. While IER is almost inactive, zeolites with a 3D pore structure and an acidity exceeding ρm,H+(NH3,ads) = 250 µmol·gcat.−1 proved to be catalytically active. DME conversions of up to 2.76 mol‐% are observed. The observed product gas stream compositions confirm thermo‐dynamic considerations with back reactions / OMEn decomposition occurring as part of the equilibria under the investigated reaction conditions (90…180 °C). However, feed gas ratio variations (FA:DME = 1:2 to 1:9.5) highlighted the possibility to shift the product selectivity in favor of OMEn and suppress FA disproportionation to methyl formate. FA trimerization to trioxane is almost completely suppressed by running the reaction at 120 °C. The results presented here provide an important and unprecedented contribution to understand the complex reaction network in the OMEn synthesis reaction necessary to establish an energy efficient sustainable OMEn production process.
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Research context
OpenAlex topics: Catalysis and Oxidation Reactions · Carbon dioxide utilization in catalysis · CO2 Reduction Techniques and Catalysts
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
Affiliations
Institut für Anorganische und Analytische Chemie and Freiburger Materialforschungszentrum FMF Albert‐Ludwigs‐Universität Freiburg Albertstr 21 79104 Freiburg Germany
Funding
Bundesministerium für Bildung und Forschung
References (35)
Show source-provided references
1. 10.1021/acssuschemeng.9b0289510.1021/acssuschemeng.9b02895 ↗
2. 10.1021/acs.jced.7b0071810.1021/acs.jced.7b00718 ↗
3. 10.1007/s38313-016-0163-610.1007/s38313-016-0163-6 ↗
4. 10.1016/j.apenergy.2019.02.03510.1016/j.apenergy.2019.02.035 ↗
5. 10.1021/ie060131u10.1021/ie060131u ↗
6. 10.1016/j.cherd.2011.09.01410.1016/j.cherd.2011.09.014 ↗
7. 10.1021/acs.iecr.5b0404610.1021/acs.iecr.5b04046 ↗
8. 10.1021/acs.iecr.8b0604410.1021/acs.iecr.8b06044 ↗
9. 10.1039/D1SE01270C10.1039/D1SE01270C ↗
10. 10.1021/acssuschemeng.2c0000410.1021/acssuschemeng.2c00004 ↗
11. 10.1039/D2RE00508E10.1039/D2RE00508E ↗
12. 10.1002/cctc.20190050210.1002/cctc.201900502 ↗
13. 10.1002/chem.20220377610.1002/chem.202203776 ↗
14. 10.1016/j.seppur.2021.11953810.1016/j.seppur.2021.119538 ↗
15. 10.1021/acs.iecr.2c0079010.1021/acs.iecr.2c00790 ↗
16. 10.1002/cite.20210017310.1002/cite.202100173 ↗
17. 10.1016/j.cattod.2022.07.01510.1016/j.cattod.2022.07.015 ↗
18. 10.1016/j.catcom.2018.02.01310.1016/j.catcom.2018.02.013 ↗
19. 10.1021/acscatal.7b0070110.1021/acscatal.7b00701 ↗
20. 10.1002/cctc.20190011510.1002/cctc.201900115 ↗
21. 10.1021/acs.iecr.8b0557710.1021/acs.iecr.8b05577 ↗
22. 10.1002/1521-3773(20000616)39:12<2102::AID-ANIE2102>3.0.CO;2-E10.1002/1521-3773(20000616)39:12<2102::AID-ANIE2102>3.0.CO;2-E ↗
23. 10.1007/s10562-022-04265-z10.1007/s10562-022-04265-z ↗
24. 10.1002/cctc.20220025810.1002/cctc.202200258 ↗
25. 10.1039/C6RE00145A10.1039/C6RE00145A ↗
26. 10.1039/C7SE00053G10.1039/C7SE00053G ↗
27. 10.1016/j.fuel.2019.11592510.1016/j.fuel.2019.115925 ↗
28. 10.1016/j.apcatb.2017.06.00710.1016/j.apcatb.2017.06.007 ↗
29. 10.1021/ie301490q10.1021/ie301490q ↗
30. 10.1021/acs.iecr.0c0578010.1021/acs.iecr.0c05780 ↗
31. Walker J. F. · 1964
32. 10.1007/s10934-022-01340-z10.1007/s10934-022-01340-z ↗
33. 10.1002/cctc.20230084410.1002/cctc.202300844 ↗
34. McCusker L. · 2007
35. Effect of the Catalyst Adjustment Time: Interestingly catalytic measurements performed without a previous catalyst adjustment time at higher feed gas flows but directly at these reaction conditions (FA:DME = 1.0:2.0 reaction temperature: 90 °C flow rate of reactants(DME FA) = 1.0 g∙h−1) exhibited a significantly reduced catalytic activity (Figures 23 and 24 Supporting Information). Here the highest conversions amounted to XDME 300 mg = 1.41% (WHSV 5.2 h−1) and XDME 500 mg = 1.22% (WHSV 3.1 h−1). We note that the catalytic performance did not approach the previously observed conversion of XDME = 2.56% even after 19 h. Thus the pretreatment respectively with the feed gas flow has a significant influence on the catalytic activity. However IR spectroscopic investigations of the zeolites after catalysis and comparison with a blank sample of H‐BEA‐360 prior to catalysis did not yield any insights that could potentially explain the observed variations in catalytic activity (Figure S6 Supporting Information). Instead the catalytic results of H‐BEA‐360 (500 mg WHSV 3.1 h−1) sssindicate an initial phase of equilibrium adjustment (Figure S24 Supporting Information). After ten catalyst measurements a bypass measurement was performed to verify the feed gas flow and composition. Meanwhile the reactor was flushed with nitrogen for 20 min. The consecutive measurement also exhibits an increased conversion XDME 500 mg run11 = 1.21% compared to XDME 500 mg run10 = 1.02%. The same trend was observed after another ten measurements (XDME 500 mg run20 = 1.06% vs XDME 500 mg run21 = 1.24%).