Shape selective catalysis in methylation of toluene: Development, challenges and perspectives
- 29 Downloads
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
Unable to display preview. Download preview PDF.
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