Shape selective catalysis in methylation of toluene: Development, challenges and perspectives
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Toluene methylation with methanol offers an alternative method to produce p-xylene by gathering methyl group directly from C1 chemical sources. It supplies a “molecular engineering” process to realize directional conversion of toluene/methanol molecules by selective catalysis in complicated methylation system. In this review, we introduce the synthesis method of p-xylene, the development history of methylation catalysts and reaction mechanism, and the effect of reaction condition in para-selective technical process. If constructing p-xylene as the single target product, the major challenge to develop para-selective toluene methylation is to improve the p-xylene selectivity without, or as little as possible, losing the fraction of methanol for methylation. To reach higher yield of p-xylene and more methanol usage in methylation, zeolite catalyst design should consider improving mass transfer and afterwards covering external acid sites by surface modification to get short “micro-tunnels” with shape selectivity. A solid understanding of mass transfer will benefit realizing the aim of converting more methanol feedstock into para-methyl group.
Keywordsshape selective catalysis methylation of toluene
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We would like to greatly acknowledge the financial support from the National Natural Science Foundation of China (NSFC, Grant No. 21403303) and Major Research Plan of NSFC (No. 91434102).
- 2.Luo H, Zhao R. A review of China’s PX market in 2015 and a prospect for future. Petroleum & Petrochemical Today, 2016, 24(5): 17–19Google Scholar
- 4.Chen Q, Kong D, Yang W. Developmental trends in p-xylene production increasing technology. Petrochemical Technology, 2004, 33(10): 909–915Google Scholar
- 20.Saepurahman V M, Olsbye U, Bjørgen M, Svelle S. In situ FT-IR mechanistic investigations of the zeolite catalyzed methylation of benzene with methanol: H-ZSM-5 versus H-beta. Topics in Catalysis, 2011, 54(16-18): 1293–1301Google Scholar
- 22.Li L L, Janik M J, Nie X W, Song C S, Guo X W. Reaction mechanism of toluene methylation with dimethyl carbonate or methanol catalyzed by H-ZSM-5. Acta Physico-Chimica Sinica, 2013, 29(7): 1467–1478Google Scholar
- 31.John H A, Kolvenbach R, Al-Khattaf S S, Jentys A, Lercher J A. Enhancing shape selectivity without loss of activity—novel mesostructured ZSM5 catalysts for methylation of toluene to p-xylene. Chemical Communications, 2013, 49(10): 10584–10586Google Scholar
- 34.Tan W, Liu M, Zhao Y, Hou K K, Wu H Y, Zhang A F, Liu H O, Wang Y R, Song C S, Guo X W. Para-selective methylation of toluene with methanol over nano-sized ZSM-5 catalysts: Synergistic effects of surface modifications with SiO2, P2O5 and MgO. Microporous and Mesoporous Materials, 2014, 196: 18–30CrossRefGoogle Scholar
- 36.Zhao J C, Li G Y, Ding Y Q. Effect of antimony oxide on the acidic properties of HZSM-5. Chinese Journal of Catalysis, 1988, 9: 152–157Google Scholar
- 38.Zou W, Yang D Q, Zhu Z R, Kong D J, Chen Q L, Gao Z. Methylation of toluene with methanol over metal-oxide modified HZSM-5 catalysts. Chinese Journal of Catalysis, 2005, 26: 470–474Google Scholar
- 44.Ghosh A K, Harvey P. Toluene Methylation Process. US Patent, 7060864, 2016Google Scholar
- 46.Tong W Y, Kong D J, Liu Z C, Guo Y L, Fang D Y. Synthesis and characterization of ZSM-5/silicalite-1 core-shell zeolite with a fluoride-containing hydrothermal system. Chinese Journal of Catalysis, 2008, 29: 1247–1252Google Scholar
- 48.Zou W, Yang D Q, Kong D J, Xie Z K. Selective methylation of toluene with methanol over HZSM-5 zeolite modified by chemical liquid deposition. Chemical Reaction Engineering and Technology, 2006, 22: 305–309Google Scholar
- 51.Tan Y, Zhu R, Zhang X, Tang Y, Zeng Z. Kinetic model of toluene alkylation with methanol to produce para-xylene. Chemical Reaction Engineering and Technology, 2016, 32(2): 1–9Google Scholar
- 52.Chen Q L, Yang W M, Teng J W. Recent advances in coal to chemicals technology developed by SINOPEC. Chinese Journal of Catalysis, 2013, 34: 217–224Google Scholar
- 53.Cao J S, Zhang J M, Xu L, Liu Z M. Superiorities for developing PX production process through alkylation of toluene alcohol. Technology & Economics in Petrochemicals, 2010, 26: 8–10Google Scholar
- 54.Joseph C, Gentry S K, Lee H M. Innovations in para-xylene technology. European Chemical News, 2000, 10–16Google Scholar
- 55.Brown S H, Mathias M F, Ware R A, Olson D H. Selective paraxylene production by toluene methylation. US Patent, 6504072, 2003Google Scholar
- 56.Chang C D, Rodewald P G Jr. Zeolite Catalysts Having Stabilized Hydrogenation—Dehydrogenation Function. US Patent, 6541408, 2003Google Scholar
- 61.Zhou J, Wang Y D, Zou W, Wang C M, Li L Y, Liu Z C, Zheng A M, Kong D J, Yang W M, Xie Z K. Mass transfer advantage of hierarchical zeolites promotes methanol converting into para-methyl group in toluene methylation. Industrial & Engineering Chemistry Research, 2017, 56(33): 9310–9321CrossRefGoogle Scholar