Several typical methanol to olefin technologies

     At present, representative methanol to olefin technologies mainly include: UOP/HydroMTO process jointly developed by UOP (an American company) and Hydro (a Norwegian company), MTP process of Lurgi, Germany, DMTO process of Dalian Institute of Chemical Physics, Chinese Academy of Sciences, SMTO process of Sinopec Shanghai Petrochemical Research Institute, SHMTO process of Shenhua Group, circulating fluidized bed methanol to propylene (FMTP) process of Tsinghua University, etc.

① UOP/HydroMTO process

      This process uses crude methanol or product grade methanol as raw materials to produce polymer grade ethylene/propylene. The reaction adopts a fluidized bed reactor, with a reaction temperature of 400-500 ℃ and a pressure of 0.1-0.3 MPa. The selectivity of ethylene/propylene can reach 80%, and the molar ratio of ethylene to propylene can be 0.75-1.50; The catalyst model is MTO-100, and the main component is SAPO-34 (silicon, aluminum, phosphorus). In order to improve the yield of ethylene and propylene in the product gas, UOP company has developed a technology that couples the methanol to olefin process with the C4 and C5 olefin catalytic cracking process (OCP). The selectivity of diene (ethylene+propylene) can reach up to 85%~90%, and the ethylene/propylene ratio can be adjusted over a large range. In 2008, UOP collaborated with Total Company to establish an integrated demonstration project for methanol to olefins using MTO and OCP processes in Feru, Belgium. The project had a methanol processing capacity of 10t/d, verifying its integrated process flow and reliability in scaling up to a million ton industrial scale.

② LurgiMTP process

      Lurgi, a German company, has been developing the MTP process since 1996, using the zeolite based modified ZSM-5 catalyst from Sudchemie, a German chemical company. This catalyst has high selectivity for low-carbon olefins; In May 2004, the industrial demonstration test of its methanol treatment capacity of 360kg/d was successful. This process consists of three fixed bed reactors (2 operating and 1 standby), each with six catalyst beds. However, there are essentially two forms of reactors to choose from, namely fixed bed reactors (only producing propylene) and fluidized bed reactors (capable of co producing ethylene/propylene). In the usual production process, the target product of the LurgiMTP process is propylene. Firstly, methanol is dehydrated and converted to dimethyl ether, and then dimethyl ether, methanol, and water enter the first MTP reactor. The reaction takes place at 400-450 ℃ and 0.13-0.16MPa, with a conversion rate of over 98.99% for methanol and dimethyl ether. Propylene is the main product, but also produces some ethylene, LPG, and gasoline products as by-products; Meanwhile, the second and third MTP reactors were set up to achieve a higher propylene yield (up to 71%).

③ DMTO process of Dalian Institute of Chemical Physics, Chinese Academy of Sciences

      Dalian Institute of Chemical Physics of the Chinese Academy of Sciences (hereinafter referred to as Dalian Institute of Chemical Physics) began to carry out MTO research in the 1980s, and in the early 1990s, it pioneered the "new process method for producing low-carbon olefins from syngas through dimethyl ether (hereinafter referred to as SDTO method)" internationally. This process consists of two stages of reaction. The first stage involves the highly selective conversion of syngas to dimethyl ether on a metal zeolite bifunctional catalyst. The second stage involves the highly selective conversion of dimethyl ether to low-carbon olefins such as ethylene and propylene on a SAPO-34 molecular sieve catalyst. After that, through technological breakthroughs, it is simplified to directly produce olefins from syngas through methanol. The SAPO-34 molecular sieve catalyst is used to achieve the catalytic conversion of methanol to olefins in a dense bed circulating fluidized bed reactor. The catalyst grades include DO123 series (mainly producing ethylene) and DO300 series (mainly producing propylene). In 2004, Dalian Institute of Chemical Physics, Shaanxi Xinxing Coal Chemical Technology Development Co., Ltd., and Sinopec Luoyang Petrochemical Engineering Company collaborated to develop a complete set of DMTO industrial technology. A 10000 ton methanol to olefin industrial test facility was built, and the industrial test was completed in 2006. The methanol conversion rate was nearly 100%, and the C2=~C4=selectivity reached over 90%. In August 2010, the world's first million ton industrial unit using DMTO technology - Shenhua Group Inner Mongolia Baotou Coal to Olefin Project was completed and put into operation. This project includes a 1.8 million ton/year coal based methanol unit and a 600000 ton/year polyolefin (polyethylene, polypropylene) combined petrochemical unit. The methanol conversion rate reaches over 99.9%, and the selectivity of ethylene+propylene reaches over 80%. The product meets the specifications of polymer grade olefin products.

      On the basis of the DMTO process, Dalian Institute of Chemical Physics further developed the DMTO-II process. This process adds a C4 and above recombination splitting unit, which means that the C4 and above components produced by the olefin separation unit enter the cracking reactor. The cracking reactor adopts a fluidized bed reactor, and the catalytic cracking unit uses the same catalyst as methanol conversion. In the fluidized bed reactor, the catalytic cracking of C4+components is achieved, generating mixed hydrocarbon products mainly composed of ethylene and propylene. The obtained mixed hydrocarbons are mixed with methanol conversion product gas and enter the separation system for separation. By increasing the cracking unit, the yield of ethylene and propylene can be increased from 80% to about 85%, and the methanol consumption of 1 ton of light olefin can be reduced from 3 tons to 2.6~2.7 tons. The yield of diene can be increased by 10% compared to the DMTO process. The C4+conversion reaction and methanol conversion reaction in this process use the same catalyst, and both methanol conversion and C4+conversion systems use fluidized bed technology, achieving mutual coupling between methanol conversion and C4+conversion systems. In December 2014, the DMTO-II industrial demonstration plant was successfully launched at Shaanxi Pucheng Clean Energy Chemical Co., Ltd., producing polymer grade propylene and ethylene. In addition, Gansu Pingliang Huahong Huijin Coal Chemical Co., Ltd. will also adopt DMTO-II technology in its 700000 ton/year olefin project. In recent years, DMTO technology has been applied and licensed for industrial use in more than 20 units in China, with a total olefin production capacity exceeding 10 million tons per year. On the basis of DMTO-II technology, Dalian Institute of Chemical Physics is actively researching DMTO-III technology in order to increase the processing capacity of DMTO single unit from the existing level of 1.8 million tons/year to over 3 million tons/year, and the one-way methanol conversion rate and olefin selectivity are not lower than DMTO-II technology. The institute completed the research and development of DMTO-III technology catalysts and laboratory pilot scale up of reaction processes in 2019, and is currently preparing a million ton process package.

④ Sinopec SMTO process

       Sinopec Shanghai Petrochemical Research Institute began the research and development of MTO technology in 2000. In 2007, the institute collaborated with Sinopec Engineering Construction Company to develop a complete set of SMTO technology, and built a 100t/d SMTO industrial test facility at Yanshan Petrochemical in Beijing. This technology uses a self-developed SMTO-1 catalyst, with a methanol conversion rate of over 99.5%, a selectivity of over 81% for ethylene+propylene, and a selectivity of over 91% for ethylene+propylene+butene. In 2008, the institute completed the development of the SMTO process package with an annual methanol feed of 1.8 million tons.

       In October 2011, the Zhongyuan Petrochemical methanol to olefin demonstration project using SMTO technology was successfully put into operation, with an annual processing capacity of 600000 tons of methanol, producing 100000 tons of polyethylene and 100000 tons of polypropylene. In October 2011, the Zhongtian Hechuang Coal to Olefin Coal Deep Processing Demonstration Project opened up the entire process and produced qualified polyethylene and polypropylene. The project is located in Ordos, Inner Mongolia, and adopts GE coal water slurry gasification technology and SMTO technology, mainly including 3.6 million tons/year of methanol, 2 x 1.8 million tons/year of methanol to olefin, 670000 tons/year of polyethylene, and 700000 tons/year of polypropylene. It is currently the world's largest coal to olefin project.

      In January 2017, the Zhong'an United Coal Chemical Integration Project located in Huainan, Anhui Province resumed work. The project adopts Sinopec's single nozzle dry powder coal gasification furnace (SE furnace) and SMTO technology, and is divided into two phases. The first phase of the project involves the construction of 1.7 million tons/year of coal to methanol, as well as the conversion of olefins and derived products. In addition, projects such as Henan Hebi with an annual output of 600000 tons and Guizhou Zhijin with an annual output of 600000 tons of coal to olefins also adopt the SMTO process. The industrial application results of SMTO technology show that its ethylene selectivity is 42.10%, propylene selectivity is 37.93%, C2~C4 selectivity is 89.87%, methanol conversion rate is 99.91%, methanol consumption is 2.92 t/t, and coking rate is 1.74%.

⑤ Shenhua Group SHMTO Process

      In 2010, the world's first large-scale industrial methanol to olefin unit (using DMTO technology) was successfully tested in Baotou, Shenhua Group, based on the rich experience accumulated during the industrial operation of the demonstration unit, developed a large number of new processes and technologies, including the development of MTO new catalyst (SMC-1) and MTO new process. In 2012, the new methanol to olefin catalyst SMC-1 was successfully developed and used in the Baotou MTO unit. In the same year, Shenhua Group applied for a patent for a device and method for converting methanol to low-carbon olefins, and completed the development of a new methanol to olefin (SHMTO) process package with an annual output of 1.8 million tons. In September 2012, the Shenhua Xinjiang Ganquanbao 1.8 million tons/year methanol to 680000 tons/year olefin project using the SHMTO process was successfully put into trial operation. The industrial operation of the unit showed that its ethylene selectivity was 40.98%, propylene selectivity was 39.38%, C2~C4 selectivity was 90.58%, methanol conversion rate was 99.70%, and coking rate was 2.15%.

⑥ Tsinghua University FMTP Process

       The fluidized bed methanol to propylene process (FMTP process), jointly developed by Tsinghua University, China Chemical Engineering Corporation, and Huaihua Group, completed industrial trials in Anhui Huaihua Group in October 2009. It uses SAPO-18/34 molecular sieve catalyst and fluidized bed reactor, with a methanol feed rate of 4250kg/h, a methanol conversion rate of 99.9%, a propylene/ethylene ratio of 1.18:1 in the product, and an ethylene+propylene selectivity of 70.6%. Overall, the FMTP process is an improvement on the MTP process, which can adjust the propylene/ethylene ratio from 1.2:1 to 1:0 (all propylene production). Using this technology to produce olefin products mainly composed of propylene, the total yield of diene (ethylene+propylene) can reach 88%, and the raw material methanol consumption is 2.62 t/t of diene. On March 7-8, 2024, Gansu Pingliang Huating Coal Industry Group successfully passed the environmental protection acceptance and the completion acceptance of the 600000 ton methanol to 200000 ton polypropylene (FMTP) technology demonstration project and the installation of the river discharge outlet. The project consumes 600000 tons of methanol annually, produces 160000 tons of polypropylene, 19000 tons of liquefied gas, 21000 tons of propane, 14000 tons of gasoline, 8000 tons of fuel gas, and 28000 tons of methyl tert butyl ether (MTBE) annually.