The differences between MTO and MTP in methanol-to-olefins production

Quote: “Tsinghua University’s FMTP: Using fluidized bed technology, the catalyst is different from that used in Lurgi processes; ethylene is also recycled, resulting in approximately 75% propylene and 5% ethylene.” DMTP developed by the Dalian Institute of Chemical Physics: By using fluidized-bed technology and C4 reprocessing, on catalysts different from those used in DMTO, it is possible to achieve approximately 80% propylene and 5% ethylene. ” Could you provide a detailed explanation of the “reprocessing” technique? What are the differences between the catalysts from Tsinghua University and Dalian Institute of Chemical Physics compared to ZSM-5?

Both Tsinghua University and the Institute of Physical Chemistry likely use SAPO molecular sieve catalysts. Due to its smaller pore diameter compared to ZSM-5, SAPO molecular sieve can significantly improve the selectivity for ethylene and propylene. “\"Reprocessing\" refers to returning substances such as ethylene produced in the reaction back to the reactor for further reaction; through processes like polymerization, coupling, and cracking, propylene is generated again, thereby ultimately increasing the yield of propylene

The ability of SAPO molecular sieve to produce propylene through processes such as the polymerization, coupling, and cracking of cyclic substances is relatively poor!

This post was last edited by wsc39 on 2009-5-5 16:05. MTO refers to a chemical process technology that uses methanol synthesized from coal or natural gas as a raw material, and employs a fluidized-bed reaction mechanism similar to that in catalytic cracking units to produce low-carbon olefins. As early as the 1970s and 1980s, the Dalian Institute of Chemical Physics under the Chinese Academy of Sciences began research and development on the new MTO technology, which was later included in the key scientific and technological projects of the **\"Eighth Five-Year Plan\". During the research and development process, the institute not only carried out key technology development such as mechanism studies, laboratory-scale tests, catalyst preparation, and pilot-scale scaling up, but also filed more than 20 patents at home and abroad, thereby establishing its own intellectual property rights. Meanwhile, researchers from the United States, Norway, Germany, and other countries have also invested human and financial resources in developing the new MTO process. Currently, the representative MTO process technologies include those from UOP, UOP/Hydro, ExxonMobil, and the Dalian Institute of Chemical Physics in China. In the past, due to factors such as relatively low crude oil prices and high methanol production costs, this technology has not been put into industrial use, neither domestically nor internationally. The MTP process is a process for converting methanol into propylene. The MTP process opens up a new route for producing basic organic chemical raw materials from coal or natural gas; it is the most promising alternative to the traditional method of producing olefins from naphtha, and it represents an effective way to facilitate the expansion of coal chemistry into the petrochemical industry. Research on methanol-to-olefins conversion focuses primarily on developing catalysts with high activity, good selectivity, and high stability. Research has found that molecular sieve materials can serve as good catalysts for the conversion of methanol into olefins. The methanol-to-olefins process mainly consists of two steps. First, natural gas is converted into crude methanol, and then methanol is converted into olefins, mainly ethylene and propylene. Representative processes include UOP/HYDRO’s Methanol to Olefins (MTO) process and Lurgi’s Methanol to Propylene (MTP) process. --Note: This post was copied from the Haichuan Chemical Industry Forum; the address of this post is: http://bbs.hcbbs.com/viewthread.php?tid=454624

The last edit to this post was made by Zhenzhen Youci on 2009-5-8 at 21:28. The MTO catalyst is mainly SAPO-34, while the MTP catalyst is ZSM-5.

What other process differences are there between MTP and MTO?

Methanol, as a fuel and other common chemical raw material, can replace part of the gasoline (methanol gasoline) and diesel (dimethyl ether) produced from crude oil, and it is already well known to people. However, not many people may be aware of it as a raw material for producing plastics. Plastics are mostly produced by processing crude oil, especially the two most widely used plastic raw materials – polyethylene and polypropylene – which are almost always manufactured through the cracking of crude oil sources such as naphtha. Due to shortages of crude oil resources and rising oil prices, polyethylene and polypropylene are becoming increasingly scarce and their prices keep climbing. Particularly in China, where demand for plastics is growing rapidly, the imbalance between supply and demand is becoming more severe. It is estimated that in 2010, the demand for polyethylene will be 15.88 million tons, while production will be 9.25 million tons, resulting in a deficit of 6.33 million tons ； The demand for polypropylene in 2010 is expected to be 12.13 million tons, with production at 7.5 million tons, resulting in a deficit of 4.63 million tons. Therefore, a large amount of olefins is still needed domestically to fill this significant gap. However, China has abundant coal but little gas and a shortage of oil; using crude oil as a raw material to produce olefins cannot meet market demand. Coal-to-methanol technology is already mature; the key lies in methanol-to-olefins technology, which converts methanol into olefins and separates out products such as ethylene, propylene, and butylene for use in downstream processes (such as polymerization). In recent years, the methanol-to-olefins (MTO and MTP: the MTP process primarily produces propylene, while the MTO process can produce both ethylene and propylene) technology has become a focal point in the C1 chemical industry both domestically and internationally. It represents the new olefin production technology with the most promising industrialization prospects in the world. In particular, with facilities set to be put into operation both domestically and abroad, their huge potential for development has attracted widespread attention worldwide. This is of great significance especially for our country, which lacks oil resources but is rich in coal. I believe that the industrialization of methanol-to-olefins production is on the horizon ； The production of low-carbon olefins such as ethylene and propylene from methanol is the most promising process route to replace naphtha as a feedstock for olefin production, and the development of this technology has now reached a mature stage. Since methanol can be produced from coal, the industrialization of methanol-to-olefins technology will open up a new process route for producing basic organic chemical raw materials through coal gasification. This approach helps to change the product profile of traditional coal chemical industries and represents an effective way to facilitate the development of coal chemistry in the direction of petrochemicals. At the same time, high oil prices create more opportunities for enterprises to grow, bringing them better investment returns. Therefore, the production of olefins from methanol holds particular strategic significance; it is hoped that participants will pay close attention to this and seize the opportunity to embrace the post-methanol era. Since the key technology of this project is methanol-to-olefins technology, MTO draws on refinery catalytic cracking and regeneration processes as well as ethylene cracking technologies. In addition, it also makes use of coal chemical technologies such as coal-to-syngas and synthetic methanol production, as well as polyethylene and polypropylene production technologies from ethylene plants. Drawing on my over 20 years of experience working in refineries, ethylene plants, petrochemical design institutes, and coal chemical projects – particularly as the technical leader for ongoing methanol-to-olefins projects – I will provide a preliminary exploration and introduction in this report regarding the significance of methanol-to-olefins projects, their market prospects, investment returns, technical status, and the current progress of these projects. This information is intended to serve as a reference for the attendees, as well as for discussion with various leaders and experts.

Methanol to Olefins (MTO) and Methanol to Propylene are two important new C1 chemical processes. They refer to chemical technologies that use methanol synthesized from coal or natural gas as a raw material, and employ a fluidized-bed reaction mechanism similar to that in catalytic cracking units to produce low-carbon olefins. 　　In the 1970s, while researching the use of ZSM-5 catalysts to convert methanol into other oxygen-containing compounds, the American company Mobil discovered the Methanol to Gasoline (MTG) reaction. In 1979, New Zealand **built the world’s first MTG plant using natural gas, with a capacity of 750,000 tons per year; it came online in 1985 but was shut down for economic reasons. 　　Based on the analysis of the MTG reaction mechanism, low-carbon olefins are intermediate products in the MTG reaction; therefore, the successful development of the MTG process has facilitated the development of the MTO process. Some well-known international petrochemical companies, such as Mobil, BASF, UOP, Norsk Hydro, and others, have invested heavily in technology development. 　　Based on the ZSM-5 catalyst developed by the company, Mobil was the first to conduct research on the conversion of methanol into ethylene and other low-carbon olefins. However, breakthrough progress was achieved through the UOP/Hydro MTO process, developed through a collaboration between UOP and Norsk Hydro, using the UOP MTO-100 catalyst. 　　Domestic research institutions, such as the Dalian Institute of Chemical Physics under the Chinese Academy of Sciences, the China University of Petroleum, and the Sinopec Research Institute of Petrochemical Technology, have also carried out similar work. Among them, the process route developed by the Dalian Institute of Chemical Physics for producing low-carbon olefins from syngas via dimethyl ether (SDTO) is innovative; compared with the traditional MTO process that uses methanol to produce low-carbon olefins from syngas, it features a higher CO conversion rate of over 90%, and reduces construction costs and operating expenses by 50% to 80%. When the D0123 catalyst is used, the product is mainly ethylene, while when the D0300 catalyst is used, the product is mainly propylene. I. Catalytic Reaction Mechanism The main reaction pathways in MTO and MTG are as follows: 2CH3OH → C2H4 + 2H2O 3CH3OH → C3H6 + 3H2O Methanol first undergoes dehydration to form dimethyl ether (DME); the resulting equilibrium mixture consists of methanol, dimethyl ether, and water. It is then converted into lower alkenes, which further undergo hydrogen transfer, alkylation, and polycondensation reactions to produce alkanes, aromatics, cycloalkanes, and higher-degree alkenes. Methanol is dehydrated to dimethyl ether under the action of a solid acid catalyst, with the intermediate being a protonated surface methoxy group ； The conversion of low-carbon olefins into alkanes, aromatics, cycloalkanes, and higher-carbon olefins proceeds via a typical carbocation mechanism involving hydrogen transfer reactions ； There are various theoretical explanations for the conversion of dimethyl ether into low-carbon olefins, and no consensus has been reached yet. 　　The MTO catalyst initially developed by Mobil was ZSM-5, with an ethylene yield of only 5%. The name of the improved process is MTE, which stands for methanol to ethylene conversion; it initially used a fixed-bed reactor, but was later changed to a fluidized-bed reactor, with selectivities of 45% and 25% for ethylene and propylene, respectively. 　　The MTO-100 catalyst developed by UOP, using SAPO-34 as the active component, exhibits significantly higher ethylene selectivity than ZSM-5, enabling breakthrough progress in the MTO process. Their selectivities for ethylene and propylene are 43%–61.1% and 27.4%–41.8%, respectively. 　　Judging from recently published patents abroad, the focus of MTO research and development remains on improving catalysts to enhance the selectivity for low-carbon olefins. Introducing various metal elements into the SAPO-34 framework yields molecular sieves known as MAPSO or ELPSO, which is one of the important methods for catalyst modification. The introduction of metal ions causes changes in the acidity of the molecular sieve as well as in the size of its pore openings. Smaller pore openings restrict the diffusion of large molecules, which facilitates an increase in the selectivity for small molecular olefins. This leads to the formation of acid centers of moderate strength, which in turn promotes the production of olefins. 　　 II. Introduction to MTO Process Technologies The representative MTO process technologies available abroad currently include those from UOP/Hydro and ExxonMobil, as well as Lurgi’s MTP technology. 　　The process flows of ExxonMobil and UOP/Hydro are not very different; both use fluidized bed reactors in which methanol reacts, and the resulting products are separated and purified to yield ethylene, propylene, and light fuels. Currently, the UOP/Hydro process is in operation at the methanol plant of a Norwegian oil company, achieving a methanol conversion rate of 99.8%, an propylene yield of 45%, an ethylene yield of 34%, and a butene yield of 13%. 　　Ruchi Company focuses on the development of a new process for producing pure propylene from methanol, using adiabatic fixed-bed reactors with intercooling, and specialized zeolite catalysts provided by Southern Chemical Company, which results in a high selectivity for propylene. According to Luchi Company, the investment cost for the plant capable of producing 1,600 tons of propylene per day is $180 million. Reports suggest that Lurgi’s methanol-to-propylene technology will be put into commercial production for the first time, with a 100,000 tons per year propylene plant being built in Iran, which is expected to begin operations in 2009. 　　Judging from recently published patents abroad, MTO has made some new improvements. 　　1. Using dimethyl ether (DME) as an intermediate in the MTO process: Water or water vapor can be harmful to catalysts; reducing water usage also helps to save on investment and production costs. The amount of water generated when producing the same quantity of light olefins is twice as much with methanol as it is with dimethyl ether, so the size of the equipment required can be reduced, thereby lowering production costs. 　　2. Flexible production of olefins through the olefin disproportionation route The ratio of ethylene to propylene can be adjusted by changing the reaction temperature; however, increasing the temperature affects the catalyst’s lifespan. Through disproportionation reactions, ethylene and butylene can be used to produce propylene, or propylene can be disproportionated into ethylene and butylene, without affecting the catalyst’s lifespan, thereby allowing for more flexible control over the product distribution. 　　3. Using methane as a reaction diluent 　Using methane as a diluent reduces the damage to the catalyst compared to using water or water vapor as diluents. 　　 III. Current Development Status of MTO Process Technology in China The Dalian Institute of Chemical Physics, Chinese Academy of Sciences, was the first research institution in China to engage in the development of MTO technology. The institute has been working on the production of olefins from methanol since the 1980s. “Pilot tests in the laboratory were completed during the Sixth Five-Year Plan period, while pilot scale tests with a capacity of 300 tons per year (for methanol treatment) were completed during the Seventh Five-Year Plan period ； The use of mesoporous ZSM-5 zeolite catalysts achieved the internationally advanced level at that time. In the early 1990s, a new international process was developed for producing low-carbon olefins from syngas via dimethyl ether (referred to as the SDTO method), which was designated as a key scientific and technological research project under the **\"Eighth Five-Year Plan\"**. This new process consists of two reaction stages: the first stage involves the highly selective conversion of syngas into dimethyl ether using a metal-zirconia bifunctional catalyst, while the second stage involves the highly selective conversion of dimethyl ether into low-carbon olefins such as ethylene and propylene using a SAPO-34 molecular sieve catalyst. 　　The SDTO new process has the following features: 1. The production of dimethyl ether from syngas overcomes the thermodynamic limitations of the methanol production process from syngas; the CO conversion rate can approach 100%, and investment can be saved by 5–8% compared to the process of producing low-carbon olefins from syngas via methanol ； 　　2. The use of a small-pore phosphosilicaluminate (SAPO-34) molecular sieve catalyst results in a **higher ethylene selectivity** compared to the ZSM-5 catalyst ； 　　3. The use of a fluidized bed reactor in the second stage allows for effective removal of reaction heat, enabling continuous operation of reaction and regeneration ； 　　4. The new process is flexible; its two-stage reaction process can be combined to form a complete process for producing olefins, or it can be used separately. In particular, the SAPO-34 molecular sieve catalyst can be used directly in the MTO process. 　　In the synthesis of SAPO-34 catalysts, the RIKEN Institute has successfully developed a method for producing SAPO-34 molecular sieves using domestically available and inexpensive triethylamine or diamines as templates, reducing the production cost by over 85% compared to the method that currently uses tetraethylammonium hydroxide as a template, which is widely used both domestically and internationally. 　　Last August, after consultations, the Dalian Institute of Chemical Physics, Luoyang Petrochemical Engineering Company, and Shaanxi Xinxing Coal Chemical Technology Development Co., Ltd. formally signed a cooperation agreement for the \"Industrial Pilot Project for Producing Low-Carbon Olefins from Methanol.\" They agreed to first build a demonstration plant with a capacity of 10,000 tons, in order to fully understand and verify the issues that remain unresolved in the MTO process during the research and pilot stages. This approach is intended to lay a solid technical foundation for the construction of larger-scale MTO industrial plants with capacities of millions of tons, thereby helping to develop new coal chemical routes in China for producing low-carbon olefins from non-petroleum resources. It is reported that the total investment for this project is 60 million yuan, with a construction period of 12 months for the testing facility and a testing operation period of 6 months. The construction, installation, and commissioning of the testing apparatus are scheduled to be completed by July this year, after which it will begin operating for experiments; all testing activities are to be finished by the end of this year. This project aims to conduct engineering verification and assessments on issues such as the selection of MTO process technologies, the design of key equipment, the selection of important equipment, and the industrial application performance of catalysts, thereby providing valuable engineering experience for the industrialization of MTO. 　　Not only in scientific research but also in the construction of large-scale MTO plants, in addition to our company’s Baotou coal-to-olefins project, various coal-producing provinces in China have also taken concrete actions. 　　Shaanxi Province has recently launched three large-scale coal chemical projects for investment attraction; these three projects are located in the Yushen coal field in northern Shaanxi, and involve an MTP project capable of producing 2 million tons of methanol and 600,000 tons of propylene per year ； The MTO project in the Yuheng coal field, which produces 2.4 million tons of methanol and 800,000 tons of olefins per year, as well as the project in the Binchang coal field in northwestern Gansu, which generates 1.5 million tons of methanol, 273,000 tons of ethylene, and 227,000 tons of propylene per year. 　　The main technologies employed in the Yushen Coalfield project are Texaco’s coal-to-syngas technology, LuChi Company’s synthetic methanol technology, and methanol-to-propylene technology; the total investment amounts to approximately 9.671 billion yuan ； For the Yuheng coalfield project, the MTO process technology developed by UOP/Hydro has been preliminarily recommended for use; meanwhile, Texaco’s coal-to-syngas technology, Lurgi’s methanol synthesis technology, and again UOP/Hydro’s MTO process technology are suggested for this project. The total investment required is 8.388 billion yuan. 　　There is also the methanol-to-propylene project at the Huaibei coal mine in Anhui Province of our country; it is said that this project will use syngas produced from coal to manufacture 2 million tons of methanol per year (with a 500,000 tons per year methanol plant to be built first, with completion planned within 3 years). Luchi Company will provide methanol production technology as well as Methanol to Propylene (MTP) technology, with a propylene production capacity of 350,000 tons per year. 　　At present, China is facing a shortage of raw material resources such as naphtha and light diesel. Relying on these as the sole source for producing low-carbon olefins to meet the country’s increasing annual demand for such compounds is clearly not feasible; it is necessary to find a new approach. If industrial development of coal-based MTO processes is accelerated in China’s regions rich in coal resources, thereby diversifying the raw materials used for the production of low-carbon olefins such as ethylene and propylene, this would constitute an effective way to address the country’s shortage of oil resources and to promote the rapid growth of its low-carbon olefin industry. It would also help those provinces in China that have abundant coal resources to turn these advantages into practical benefits. On the other hand, in recent years, China’s methanol market has remained at high levels for an extended period, sustaining strong public interest in investing in methanol. There are already concerns regarding the market prospects for methanol products in the coming years. The MTO technology also provides a guarantee for fundamentally solving the future of the methanol market.

Assuming international oil prices remain stable at $50-$60 per barrel in the long term, how do the economic aspects of MTO and MTP compare?

“DMTP developed by the Dalian Institute of Chemical Physics: it uses fluidized bed technology along with C4 reprocessing. Does the original poster know what technology is employed for C4 reprocessing – a fixed bed? Still a fluidized bed? Are C4 reprocessing and MTP the same catalyst?