An in situ methylation of toluene using syngas over bifunctional mixture of Cr2O3/ZnO and HZSM-5
- Title
- An in situ methylation of toluene using syngas over bifunctional mixture of Cr2O3/ZnO and HZSM-5
- Other Titles
- ZnO and HZSM-5
- Author
- 서영웅
- Keywords
- Syngas; Toluene methylation; Methanol synthesis catalyst; Cr2O3/ZnO; HZSM-5; Bifunctional catalyst; Xylenes production.
- Issue Date
- 2013-09
- Publisher
- Elsevier B.V.
- Citation
- Applied Catalysis A, General, 10 September 2013, 466, p.90-97
- Abstract
- The in situ methylation of toluene using syngas (in situ methylation hereafter) was studied to produce xylenes over bifunctional catalysts comprising Cr2O3/ZnO (CrZ) and HZSM-5 (SiO2/Al2O3=30) in a fixed-bed down-flow reactor at 460psig. In this study, three basic aspects in the in situ methylation were investigated: (1) the catalytic activity of CrZ as the methanol synthesis catalyst with respect to the equilibrium conversion, (2) the evaluation of catalytic synergies in the in situ methylation over bifunctional catalyst, and (3) the effect of the ratio of catalytic functions regarding the ratio of methanol synthesis catalyst to HZSM-5, and their intimacy. The CrZ catalyst exhibited very low CO conversion to methanol in the methanol synthesis reaction, which is controlled by the equilibrium. However, the bifunctional mixture of CrZ and HZSM-5 catalysts exhibited significant catalytic synergies in the in situ methylation in terms of catalytic activity and product selectivities, with about a 10-times-higher CO conversion rate, and 2- to 3-times-higher toluene conversion and xylene production rates compared to the monofunctional catalysis of methanol synthesis and toluene disproportionation, respectively. The in situ methylation also gave rise to higher catalytic performance than in typical toluene methylation conducted with a molar feed ratio of methanol/toluene of 0.5. The catalytic synergy was manifested when both metallic and acidic functions were brought into close intimacy with a weight ratio of CrZ/HZSM-5 close to one in the in situ methylation.
- URI
- https://www.sciencedirect.com/science/article/pii/S0926860X13003554?via%3Dihubhttp://hdl.handle.net/20.500.11754/51135
- ISSN
- 0926-860X
- DOI
- 10.1016/j.apcata.2013.06.025
- Appears in Collections:
- COLLEGE OF ENGINEERING[S](공과대학) > CHEMICAL ENGINEERING(화학공학과) > Articles
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