Dimethyl ether process flow

The Southwest Chemical Research Institute has the most; it seems that Hangzhou Linda is also working on this now!

Sichuan Tianyi Technology Co., Ltd. is a joint-stock limited company established with the approval of the **Economic and Trade Commission. It was founded with the Southwest Chemical Research and Design Institute (formerly the Southwest Chemical Research and Design Institute of the Ministry of Chemical Industry) as the main initiator, in collaboration with Zhejiang Fanghua Daily Chemicals Group Company, Sinochem Research Institute of Chemical Science and Technology (formerly the Research Institute of Science and Technology of the Ministry of Chemical Industry), Chengdu ChenGuang Chemical Research Institute of the Ministry of Chemical Industry, and China National Rubber Group Carbon Black Industry Research and Design Institute (formerly the Carbon Black Industry Research and Design Institute of the Ministry of Chemical Industry). In January 1999, it was recognized as a high-tech enterprise after evaluation by the Ministry of Science and Technology and the Chinese Academy of Sciences. In August of the same year, it was registered for business in the **-level High-Tech Industrial Development Zone in Chengdu, Sichuan. In December 2000, with the approval of the China Securities Regulatory Commission, 45 million shares of publicly tradable stock were issued on the Shanghai Stock Exchange (stock code 600378). The company’s total share capital was 115.72 million shares, with a registered capital of 70.7239 million yuan at that time. 　　The company completed its split-share structure reform in November 2006; during this period, through share transfers, the total share capital of the company has now reached 245.6134 million shares. On October 24, 2007, the Southwest Chemical Engineering Research and Design Institute transferred 56.8213 million shares (representing 23.13% of the total share capital) to China Haohua Chemical (Group) Corporation. The current legal representative is Chen Baotong, while the general manager is Wang Xuezhai. Introduction to the Production Technology of Dimethyl Ether via Methanol Gas Phase Method 1. The Dimethyl Ether Industry Dimethyl ether is a clean and environmentally friendly fuel, and it is an alternative energy source that is recognized and encouraged for development. In an era of high oil prices, the coal-based dimethyl ether industry will become a key force in effectively reducing China’s dependence on imported oil. The use of dimethyl ether as a substitute for liquefied petroleum gas (LPG) has been accepted by consumers, and the National Development and Reform Commission, the Ministry of Construction, and the Ministry of Agriculture have each issued relevant standards. Dimethyl ether serves as a substitute for liquefied petroleum gas (LPG), not only as a fuel for household use but also with significant consumption in industrial applications such as ceramic and glass firing, as well as metal cutting and welding. A greater future use of dimethyl ether is to replace diesel as a fuel for engines in vehicles, ships, and power generation. China’s diesel consumption has exceeded 120 million tons per year, and its liquefied petroleum gas consumption is around 20 million tons per year; therefore, the industrial prospects for dimethyl ether are quite promising. The methanol-to-dimethyl ether production plant is characterized by low investment costs, high output value, and rapid returns on investment; for example, a profit of around 200 yuan per ton of product can be achieved, and the initial investment can generally be recovered within 1–3 years. In order to promote the use of dimethyl ether, the Ministry of Finance and the **State Taxation Administration issued the \"Notice on the VAT Rate Applicable to Dimethyl Ether\" (Caishui No. 72). It stipulates that, as a measure to encourage the use of dimethyl ether, starting from July 1, 2008, VAT will be levied on dimethyl ether at a rate of 13%. 2. Dimethyl ether production methods: Currently, there are mainly two types of methods for producing dimethyl ether domestically and internationally: the syngas one-step method and the methanol method, with the latter further divided into the gas-phase methanol method and the liquid-phase methanol method. The industrialization technology for the one-step synthesis gas process is not yet fully mature. At the current level of technology, the production cost is higher than that of the methanol method; technical shortcomings need to be addressed, and key technical aspects require further exploration and breakthroughs. The dimethyl ether production units that are currently in operation and those planned for construction both use the methanol process. The liquid-phase production process, due to its low operating pressure, low production capacity per reactor, and certain level of pollution, results in high investment costs and high power consumption, making it unsuitable for widespread adoption. The gas-phase methanol method is the most economical and reasonable approach for producing dimethyl ether at present. Currently, all large-scale dimethyl ether production facilities under planning or construction at home and abroad use the methanol gas-phase method. 3. The company’s new technology for methanol production via the gas phase method ※Research and development history: The company’s technology for producing dimethyl ether from methanol using the gas phase method was first developed in China in the 1980s; it was designated as a key scientific and technological project under the \"Eighth Five-Year Plan,\" and industrial production of this technology began in 1994. As early as the 1990s, 3 sets of aerosol-grade and 7 sets of fuel-grade plants were built and put into operation, and the production of fuel-grade dimethyl ether using crude methanol as raw material was successfully carried out. Subsequent continuous innovation and improvement have led to the development of advanced new technologies for the methanol vapor phase process. Two Chinese invention patents were applied for in 1995 and 2003 respectively and granted; the key technical aspects of the new methanol gas-phase process are included in the claims of these two patents. In December 2005, the first dimethyl ether fuel production facility to utilize the company’s new methanol vapor-phase technology was put into operation at Bengbu Newao Gas Company, marking a new advancement in dimethyl ether production technology. The production cost of dimethyl ether was significantly reduced, and the technical level reached world-class standards. Due to the demonstration effect of the commissioning of this facility, domestic companies have begun to plan and construct dimethyl ether fuel production plants, thus giving rise to a \"dimethyl ether craze\" in the industry. Adhering to the principles of \"striving for excellence\" and \"continuous improvement,\" the company’s R&D and design professionals have, over the years, focused on reducing energy consumption, lowering costs, and optimizing operations. The results of these ongoing technological innovations have been significant, with the technology used for dimethyl ether production being continually improved. Based on the production performance of the factory, compared with existing technologies at home and abroad, it consumes the least amount of methanol and water vapor, thereby effectively reducing the production cost of dimethyl ether. The advancement and reliability of new technologies have been proven through more than 30 units put into operation in recent years. **The Ministry of Science and Technology has designated the Southwest Chemical Engineering Research and Design Institute and Sichuan Tianyi Technology Co., Ltd. as the entities responsible for carrying out the tasks related to the “Development of Large-scale Projects for the Production of Dimethyl Ether from Methanol”, which is part of the “Key Technologies for the Production of Oxides via Non-petroleum Routes” under the science and technology support program. ※Industrial achievements: As of June 2008, more than 70 units with a dimethyl ether production capacity of 10 kt/a to 400 kt/a had been built, thanks to the technology transferred by the Southwest Chemical Engineering Research and Design Institute and Sichuan Tianyi Technology Co., Ltd. along with the engineering design provided. Of these, there are 18 units with a capacity of 100 kt/a and 9 units with a capacity of 200 kt/a; 9 of the 100 kt/a units and 2 of the 200 kt/a units are already in operation. ※Technical Features: The company’s gas-phase methanol to dimethyl ether production technology features a unique process design, low investment costs, and low production expenses. The main technical advantages are as follows: 1) When produced in conjunction with methanol plants, crude methanol can be used as the raw material, which significantly reduces production costs (primarily by reducing steam consumption; using crude methanol as a raw material can cut steam usage by about 1.5 tons per ton of dimethyl ether produced). This technology for producing dimethyl ether from crude methanol has been tested in several plants with a capacity of 100 kt/a each. 2) The reactor uses a multi-stage quench-type fixed-bed design; it has a large catalyst loading capacity, low investment costs, an appropriate reaction temperature, few side reactions, and is suitable for scale-up. It not only avoids the drawbacks of adiabatic fixed-bed reactors, such as excessive temperature rise leading to increased side reactions and a low one-pass conversion rate of methanol, but also overcomes the disadvantages of heat-exchange fixed-bed and isothermal tubular fixed-bed reactors, namely large size and limited catalyst loading capacity (a key technology protected by patents). 3) A unique vaporization distillation tower structure and separation process are employed; there is no methanol concentration tower for recovering unreacted methanol. The vaporization distillation tower performs three functions: vaporizing the feed methanol, concentrating the recovered methanol, and separating out the water contained in the feed material as well as the water generated during the reaction. It simplifies the process, reduces investment, and effectively cuts steam consumption. The steam consumption per ton of dimethyl ether produced is more than 0.5 tons less compared to similar technologies at home and abroad. It also prevents methanol loss during the operation of the methanol concentration tower (which operates at atmospheric pressure), thereby ensuring low methanol consumption effectively (a key technology protected by patent). Without adopting this patented technology, it is difficult to keep the water vapor consumption below 1.6 t/tDME. 4) A specially developed catalyst of our own is used for large-scale production; it features good activity, good thermal stability, and a dehydration reaction selectivity of over 99.5%. Furthermore, thanks to the advanced and rational design of the separation process, the separation losses of methanol and dimethyl ether are low, effectively ensuring the methanol consumption, which is a key indicator of consumption. Methanol consumption is lower than that of similar technologies at home and abroad. 5) Compared with similar technologies at home and abroad, it not only features advanced technology but is also mature and reliable, with the lowest production costs. 4. Product Quality: The product quality meets the standards of the chemical industry, HG/T3934-2007 (see table below).
| Parameter | Type I | Type II |
|-----------|-------|-------|
| Mass fraction of dimethyl ether /% | ≥ 99.9 | 99.0 |
| Mass fraction of methanol /% | ≤ 0.05 | 0.5 |
| Mass fraction of water /% | ≤ 0.03 | 0.3 |
| Copper sheet corrosion test | ≤ ---- | Grade I |
| Acidity (as H2SO4) /% | ≤ 0.0003 | --- |
Note: Acidity is tested for Type I products when used as a refrigerant.

5. Main consumptions (per ton of dimethyl ether produced):
| No. | Name | Specification | Unit | Consumption | Remarks |
|-----|------|---------------|------|------------|---------|
| 1 | Methanol | Purified crude methanol | t | 1.395–1.41 | Varies with scale and raw material purity |
| 2 | Steam | ≥1.0 MPa | t | 1.05–1.25 | Varies with scale and raw material purity |
| 3 | Recirculated cooling water | ≥0.3 MPa, ≤32°C | t/h | 70–80 | Depends on circulation rate |
| 4 | Electricity | 380/220V, 50Hz | kwh | 6–15 | Varies with scale and raw material purity |

6. Cooperation methods:
◆ Technology transfer and engineering design
◆ Technology transfer, engineering design, and hardware supply
◆ Technology transfer and EPC turnkey project delivery

Tianke Co., Ltd. – Process flow diagram for methanol-to-dimethyl ether production plant:

Contact persons and contact information:
Xu Jianping: (Phone) 028-85962836, 13608002528; (Fax) 028-85961526; (Email) **2528@163.com**
Sun Chen: (Phone) 028-85962380, 13308095252, 13808028158; (Fax) 028-85961526; (Email) sunb@tianke.com
Tang Hong: (Phone) 028-85962872, 13980604026; (Fax) 028-85884329; (Email) cdthong@163.com

Address: P.O. Box 445, Wainan Airport Road, Chengdu, Sichuan Province, Postal Code: 610225

There are several companies that provide process packages for dimethyl ether; Sichuan Tianyi has achieved relatively more success in this area. Other companies include a certain design institute in Henan and Tianchen Institute. Those interested can communicate with each other

I’d like to see the flowchart; I wonder if anyone has it?

Most of them are from Sichuan Tianyi. If you want to learn about the dimethyl ether production process, you can add me on QQ: 373734139; I’m the person in charge of that process.

The production process of dimethyl ether from methanol can be divided into three main steps: reaction, distillation, and stripping. The raw material methanol is preheated and then vaporized into methanol vapor in a vaporization tower; this methanol vapor exchanges heat with the reaction gas to increase its temperature before entering the reactor (an start-up heater is used to supply heat during startup), while the gas heat exchanger also provides cooled methanol vapor. Since the reaction is exothermic, the heat released raises the temperature of both the reactor itself and the catalyst bed. Therefore, it is necessary to inject methanol vapor at a lower temperature into the second catalyst bed in order to regulate the temperature of the hot gas stream and ensure that the reaction takes place within an appropriate temperature range. Under the operating conditions, methanol cannot be completely converted, with minor side reactions occurring; as a result, the product exiting the reactor contains dimethyl ether, methanol, water, as well as a small amount of non-condensable gases. The heat generated by the reaction is recovered through three stages of heat exchange, and after cooling, the mixture enters the crude dimethyl ether storage tank. The non-condensable gases in this tank – which contain 50–60% dimethyl ether – are cooled and then sent to a washing tower. There, the dimethyl ether is absorbed by the washing liquid, after which the non-condensable gases are released at a height of 30 meters. The boiling points of dimethyl ether, methanol, and water are -24°C, 64.7°C, and 100°C respectively; the differences between them are significant, and no azeotropes exist. The crude dimethyl ether resulting from the reaction (containing methanol, dimethyl ether, and water) is pumped into a distillation tower. The dimethyl ether condensate obtained at the top of the tower is partially recycled, while the portion that passes the analysis requirements is collected as a product and sent to the product storage tank. The aqueous methanol solution in the distillation column bottom liquid storage tank is, in order to make full use of the recovered resources, partially returned to the vaporization tower for the separation of methanol and water, and partially used as a washing liquid in the scrubber tower. The alcohol-containing wastewater from the bottom of the vaporization tower enters the stripping tower and the alkali solution tank to dilute the alkali solution; after stripping and separation, the crude methanol obtained at the top of the tower is condensed, with most of it being recycled back to the stripping tower, while a small portion is taken out and sent to the methanol intermediate tank for reuse. The process wastewater from the bottom of the stripping tower is cooled before being sent to the sewage system, or it is discharged on-site after passing quality checks. qq:459762037

http://bbs.hcbbs.com/viewthread.php?tid=101627 Download the CAD version flowchart of dimethyl ether here