Strategies for improving CO2 utilization in microchannel enabled production of dimethyl ether
Chemical Engineering and Processing - Process Intensification, cilt.151, 2020 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 151
- Basım Tarihi: 2020
- Doi Numarası: 10.1016/j.cep.2020.107914
- Dergi Adı: Chemical Engineering and Processing - Process Intensification
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Chemical Abstracts Core, Chimica, Compendex, INSPEC
- Anahtar Kelimeler: CO2, dimethyl ether, microchannel, modeling
- Boğaziçi Üniversitesi Adresli: Evet
Özet
Intensified production of dimethyl ether (DME) from CO2–containing syngas is modeled in a microreactor involving porous layers of Cu–ZnO/Al2O3 and γ–Al2O3 catalysts washcoated to the opposing faces of the reaction channels neighbored by physically segregated cooling channels. Steady–state reactive transport of syngas within catalyst layers and conservation of momentum, heat and mass are coupled with in–situ counter–current air cooling in two spatial dimensions in the context of a mathematical model that can closely predict the literature–based experimental data. Simulations run at inlet temperature, pressure, molar H2/CO and H2/CO2 ranges of 493–508 K, 20–60 bar, 2.5–4 and 5–12, respectively, commonly point out a fast rise in temperature, mostly due to CO hydrogenation, followed by its monotonic decline. Negative CO2 conversions from methanol–to–CO2 route driven thermodynamically by the methanol produced by the faster CO hydrogenation can be prevented, and CO2 conversions up to ∼10% can be obtained by dosing syngas below 498 K or by enriching syngas with CO2 to keep H2/CO2<7.5. These measures, however, reduce both CO conversion and DME yield. Distance between Cu–ZnO/Al2O3 and γ–Al2O3 layers has negligible effect on temperature distribution.