A brief history of the coal-to-olefin process development to scale in China


Olefins such as ethylene and propylene are important organic chemical raw materials and are widely used in industry, agriculture, medicine, environmental protection and other fields. In the chemical industry, the mainstream method has been to produce olefin raw materials such as ethylene and propylene through petroleum processing.

Since the 1980s, researchers at the Dalian Institute of Chemical Physics, Chinese Academy of Sciences began to explore coal-to-olefin technology. Since then, after nearly 40 years of continuous research by several generations of scientific researchers, United Engineering Company has finally successfully developed a complete set of industrialized technologies for the patented methanol-to-olefins (DMTO) process technology with independent intellectual property rights, opening up a new route for the production of olefins from non-petroleum resources.

In the 1970s, due to the global oil crisis, oil prices rose sharply, and people became concerned about the source of olefin raw materials. The first difficulty to overcome was to develop a catalyst. At that time, there were two technical routes: ZSM-5 molecular sieve catalyst and SAPO-34 molecular sieve catalyst. The former has examples of industrial application and the risk was relatively small, while the industrial application potential of SAPO-34 molecular sieve catalyst required further research. After weighing the considerations, the research team finally decided to “walk on two legs.” After several years of hard work day and night, the team synthesized the ZSM-5 zeolite molecular sieve for the first time in China, taking the first step towards realizing the strategic goal of methanol to olefins. After that, the researchers took advantage of the success and completed the scale-up synthesis of zeolite at a scale of 3 tons/year, a catalyst scale-up equipment at a scale of 4-5 tons/year, and a methanol-to-olefins fixed-bed reaction system with a daily processing capacity of 1 ton of methanol. peripheral equipment and completed pilot testing in 1993.

With the deepening of research, researchers discovered that SAPO-34 molecular sieve catalyst can significantly increase the olefin yield and has better industrial application prospects. In 1995, the team used its own new process of producing olefins from synthesis gas through dimethyl ether and completed a hundred-ton pilot test. The test results were very good, and the project was awarded the Special Prize of the Chinese Academy of Sciences Science and Technology Progress Award by the Chinese Academy of Sciences.

Then there was a “sudden change”: international oil prices fell sharply, once falling to less than 10 US dollars per barrel. As a result, the cost of coal-to-olefins was too high compared to petroleum-to-olefins. Therefore, companies were not very enthusiastic about coal-to-oil olefins production projects. For a period, research was stalled by a lack of funding.

In 1998, Liu Zhongmin’s team at CAS DICP received a special RMB 1 million scientific research grant from the Chinese Academy of Sciences. Using this funding, the team further studied the reaction mechanism of the methanol to olefins process, improved the catalyst scale-up and process technology, and continued to look for opportunities for further scale-up experiments.

In 2004, international oil prices recovered, and methanol to olefins once again ushered in development opportunities. Opportunity awaits those who are prepared. After learning that the Dalian Institute of Chemical Physics had developed world-leading methanol-to-olefins laboratory pilot technology and was looking for investments and partners, Shaanxi Province decided to cooperate with it to carry out industrial trials. In August of that year, an industrial test device with a total investment of 86.1 million yuan and an annual methanol processing capacity of 16,700 tons started construction in Huaxian County, Shaanxi Province (now Huazhou District, Weinan City). Liu Zhongmin’s team set up camp at a local chemical factory and began crucial industrial experiments.

Initially, only the methanol-to-olefins industrial test device stood alone in the entire factory area, and the factory infrastructure was rudimentary. It was under such difficult conditions that Liu Zhongmin led the team to spend more than 700 days and nights in the factory. During this period, he rarely slept soundly. Even after falling asleep at night, he would always get up after a while to see if the torch on the device was still on. If the torch burned, it meant that the device was operating normally, so he dared to lie down and squint for a while. As the technical chief, Liu Zhongmin is most worried about safety issues. With more than 100 people and a 36-meter-high large-scale device, any problem in any link might have interrupted the rare industrial test opportunity. After more than 700 days and nights of “fear and worry”, the exciting moment finally came. In May 2006, the industrial test of methanol to olefins was declared successful, and reliable data for the design and construction of large-scale equipment were obtained.

Since then, the project has continued to progress smoothly. In 2010, Shenhua Baotou’s 1.8 million tons/year methanol-to-olefins industrial unit successfully commissioned and commissioned, realizing the industrialization of coal-to-olefins for the first time in the world; in January 2011, it officially entered the commercial operation stage. As a result, China has taken the lead in achieving breakthroughs in the core technology and industrial application of methanol to olefins. The long and arduous research and development process has integrated the pursuit of scientific research and the persistence of the national strategic needs of three generations of Dalian Institute of Chemical Physics. At the 2014 National Science and Technology Awards Conference, methanol-to-olefin technology won the first prize of the National Technology Invention Award. While reaping the honors, the team members felt the burden on their shoulders became heavier. Continuous innovation and promotion of technology have become their new goals.

In 2015, the industrialization of second-generation methanol-to-olefins (DMTO-II) technology with higher olefin yields was successfully put into production, further consolidating China’s leading position in the world’s coal (natural gas)-based olefins industrialization industry.

In November 2020, the third-generation methanol-to-olefins technology passed the scientific and technological achievements appraisal. Compared with the first two generations of technology, while the size of the reactor remains basically unchanged, the third generation technology increases the methanol processing capacity from 1.8 million tons per year to 3.6 million tons, which is converted into olefin production, from 600,000 tons per year. increased to 1.35 million tons; per ton of olefin methanol consumption dropped from the previous 3 tons to 2.6 to 2.7 tons.

Not long ago, based on the third-generation methanol-to-olefins technology, the world’s largest coal-to-olefins project began construction in Ordos City, Inner Mongolia Autonomous Region. After the coal-to-olefins project is completed and put into operation, it will promote the transformation of coal resource products in Ordos and related areas from ‘general processing’ to ‘high-end manufacturing,’ help optimize the regional industrial structure, and promote the diversification of national olefin raw materials.

Up to now, Dalian Institute of Chemical Physics has signed technology implementation license contracts for 32 sets of equipment for its methanol-to-olefins series technology, with an olefin production capacity of 21.6 million tons/year (accounting for about 1/3 of the country’s current production capacity); 17 sets of industrial equipment have been put into operation, Olefin production capacity exceeds 10 million tons/year.

A brief history of the coal-to-olefin process development to scale in China
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