Traditionally, ethylene and propylene products are mainly obtained through petroleum cracking, but against the background of "rich coal, poor oil and little gas", China has developed a unique route of CTO/MTO/MTP to produce ethylene and propylene, which has become one of the six major routes of modern coal chemical industry.

From the development history, 2014-2016 years, is the fastest growing three years of the industry, olefin production capacity is explosive growth, growth rate of 126%; 2015-2016 years growth rate slowed down, but the annual growth rate is also in the level of more than 28%; 2017-2018 industry by the significant rise in raw materials and economic downward pressure, some projects delayed production, the growth rate slowed down significantly;. In 2019, the growth rate climbed again to 22.5%; and in 2020-2021, the growth rate of domestic olefin industry turned slow again, among which in 2021, under the influence of high raw material cost and extrusion of other process route varieties, the overall economy of domestic CTO/MTO/MTP is poor and most of the time is in loss, thus also fundamentally restricting the rhythm of new projects put into production.

Most of the domestic olefin enterprises are located in the northwest, and the end products are diversified: PP, PE, PO, EO, MMA, EVA, ethylene glycol, polyether, acrylonitrile, etc. The diversified downstream provides strong support for the development of the industry chain and avoids the influence of product homogenization.

In terms of process comparison, PDH is more favored in propylene production because of its limited development constraints, except for the high foreign dependence of raw materials