Technical risks of MTP and MTO?

The process for MTP involves preheating the raw material methanol to 260°C before feeding it into a fixed-bed adiabatic DME pre-reactor, where a highly active and selective catalyst is used to convert 75% of the methanol into dimethyl ether and water. Then the reaction stream is further preheated to 470°C before entering the first-stage MTP reactor, with a small amount of steam (0.3–0.8 kg/kg) added, resulting in the conversion of over 99% of the methanol and dimethyl ether. The reaction stream continues to react through the second and third MTP reactors, and finally, the reaction mixture is condensed. And separate the gaseous products, liquid organic matter, and water. The gaseous product is compressed, and trace amounts of water, CO, and dimethyl ether are removed. Further purification separates the product propylene, gasoline components, and fuel gas. The separated olefin-containing stream is returned to the MTP reactor to increase propylene production. Part of the generated water is recycled to the MTP reactor, while the other part is used to produce steam. The MTO process is a process for producing ethylene and propylene from methanol. In the 1980s, scientists at Union Carbon discovered that SAPO catalysts exhibited high selectivity for the conversion of methanol into ethylene and propylene. The typical consumption for producing ethylene is 5.6 t of methanol per ton of ethylene produced; as by-products, 0.83 t of propylene, 0.24 t of butylene, 0.1 t of C5, and 4.19 PJ of fuel gas are generated. The MT0 project in Nigeria, which aims to produce 400,000 tons of ethylene and 400,000 tons of propylene per year, as well as 2.5 million tons of methanol per year per production line, is scheduled to be completed in 2006. According to available information, the investment cost for an MTO plant with a production capacity of 300,000 tons per year of ethylene and 250,000 tons per year of propylene is estimated at $346 million (using natural gas as the feedstock). Comparison between MTO and MTP | Item | MTO | MTP |
|---------|--------|--------|---------|
| Reactor | Fluidized bed | Fixed bed |
| Catalyst | Sapo-34 (alumina-silica phosphate molecular sieve) | ZSM-5 |
| Reaction pressure / MPa | 0.1–0.3 | 0.13–0.16 |
| Reaction temperature / °C | 400–450 | 420–490 |
| Target product | Ethylene:propylene ratio of 1.5–0.75; 100% propylene | |
| Level of industrialization | 800,000 t/year, under construction; expected to come online in 2007 | 800,000 t/year, planned for construction |
| Methanol consumption per ton | 3.02 | 3.2 |
| Major patent holders | UOP/Hydro, Lurgi | In China, the Dalian Institute of Chemical Physics developed ZSM-5 and its modified catalysts in the 1980s, and small-pore SAPO-34 molecular sieve catalysts in the 1990s. | In 1993, the Dalian Institute of Chemical Physics used modified ZSM-5 series catalysts to carry out a pilot-scale test in a fixed-bed reactor (with a daily methanol feed of 1 ton) ； In 1995, a pilot test of the SDTO fluidized bed was completed at Factory T in Qingpu, Shanghai, and passed the evaluation. Methanol feed rate: 60–100 kg/d; methanol conversion rate: 100%. SAPO-34 molecular sieve catalysts are used, achieving an olefin selectivity of 84%–85%. A prize for scientific and technological advancement was awarded in 1996

SSBayf is right. I wonder if the MTP process you’re referring to is the one used by Datang Coal Chemical in China these days? Isn’t it the case that there are still no true industrial MTP plants in the world? If the Datang Coal Chemical Plant is built, it will be the world’s first MTP facility.

Currently, there are no industrial plants for either MTO or MTP, but based on the characteristics of the reactors, MTP using a fixed-bed configuration poses a lower risk. Features of MTP reactors: 1. Fixed-bed reactor, with a simple structure and lower risk of scale-up issues ； 2. Minimal reaction coking, no catalyst wear, and it can be regenerated on-site ； 3. Temperature control in the reaction is more difficult than in a fluidized bed. Characteristics of MTO reactors: 1. Fluidized bed reactors; 2. Coking occurs during the reaction, and the catalyst suffers wear, hence it is necessary to have a catalyst regeneration reactor ； 3. The reaction temperature is easier to control than in a fixed-bed reactor ； 4. Fluidized bed reactor + downward bed zoned reactor technology, high olefin conversion rate

MTP reactors come in two types: fixed-bed and fluidized-bed. The fluidized-bed reactor is represented by the MTP technology developed by Tsinghua University; it adopts a design similar to that of DCC catalytic cracking fluidized-bed reactors, with continuous operation of reaction and regeneration. The reaction temperature is easier to control compared to fixed-bed systems, and the yield of propylene is higher in this approach. Sinochem Engineering Group Corporation is constructing a 30,000-ton/year MTP plant in Huaihua, Anhui. Once it operates successfully, the capacity will be further increased to 300,000 tons, until reaching the million-ton scale. Fixed-bed reactors are represented by German Lurgi technology: in the first reactor, methanol is converted into dimethyl ether, and in the second reactor it is converted into propylene, with reaction and regeneration operating in alternating sequence. For MTP, the control of reaction temperature is of utmost importance; if the temperature cannot be controlled, side products will increase and the yield of propylene will decline. This is the drawback of fixed-bed reactors. This post was last edited by 1681818 on 2007-11-29 23:41]

The description on the 6th floor is incorrect. The FMTP at Tsinghua University is as you described it – there are no issues. As for Lurgi’s MTP system: it consists of 1 dimethyl ether reactor + 3 MTP reactors (with catalysts that can be switched and regenerated on-site) + an olefin separation unit. The olefin separation process can vary depending on the purity requirements for propylene in the downstream products

Germany’s LUCCHI MTP technology uses three reactors in a two-operate-one-regenerate configuration, with each reactor divided into 5–6 sections. The development of multi-stage reaction processes and the design of large-diameter reactors are crucial technologies. It is easy to imagine the adverse consequences that can arise if a 10-meter reactor is not properly controlled; therefore, it is only possible to determine whether these technologies are mature after industrial plants are put into operation.

This post was last edited by 1681818 on 2009-6-21 at 16:23. 5# 1681818 Fixed-bed reactor for a certain device: diameter of 11.7 meters, with a catalyst loading of 524 tons per reactor. The catalyst loading in the three reactors is 1,572 tons. At 400,000 yuan per ton, the catalyst costs 600 million yuan in investment.

Global ethylene capacity will be 17 million tons in excess in 2010 According to a report in Chemical Week on April 6, the American consulting firm S&P Global Commodity Insights recently stated that due to the global economic downturn, the addition of new ethylene production capacity, and weak market demand, global ethylene capacity will be 17 million tons in excess in 2010 – accounting for 15% of total demand – with plant utilization rates falling below 85%. 　　According to statistics, the global demand for ethylene in 2008 was 115 million tons, a decrease of about 4 million tons compared to the previous year, and global demand for ethylene is expected to remain unchanged this year. Nevertheless, new plants are still being built in the Middle East and Asia, and it is estimated that the additional ethylene production capacity in these regions will reach over 28 million tons between 2008 and 2012. To balance market supply and demand, some manufacturers are forced to shut down their production facilities. It is estimated that between 2008 and 2012, North America and Western Europe will see a reduction of over 7.5 million tons in their ethylene production capacity, and some facilities in Asia will also be shut down. By 2013, global idle ethylene capacity will reach 50 million tons, and the operating rate of plants will not exceed 90% before that year. The current ethylene market is oversupplied. The growth rate of demand for propylene was slightly higher than that for ethylene; from 2000 to 2005, the average annual growth rate of demand for propylene was 4.5%, while that for ethylene was 3.5%. The growth rate of demand for polypropylene, the largest derivative of propylene, is slightly higher than that of polyethylene, the largest derivative of ethylene. Based on this, does the MTP process have a better market prospect than the MTO process?