Ether [Chinese name] ether; Dimethyl ether; Dimethyl ether (DME); Methoxy methane. 1 15- 10-6 molecular formula] CH3-O-CH3 All C and O atoms form σ bonds with sp3 hybrid orbitals. [Relative molecular weight ]46.07[MF][ density ]C2H6O 1.6 17 Relative density (air = 1) Melting point (℃)- 138.5 boiling point (℃)-24.5 flash point (℃)-. 8 1 19(-70.7℃); 2 1905(-55℃) is a colorless flammable gas or compressed liquid with the smell of ether. Solubility: Soluble in water and ethanol. Used as solvent and refrigerant. {Prepared from methanol dehydration source or obtained by catalytic decomposition of ferric chloride formate. [Other] Critical temperature 128.8℃. The critical pressure is 5.32 MPa. Freezing point-138.5℃. The third part of the liquid density is 0.66 1: danger-danger grade: route: health hazard: it has inhibitory effect on the central nervous system and weak anesthesia. Inhalation can cause anesthesia and suffocation. Irritate the skin. Environmental hazard: explosion hazard: this product is flammable and irritating. The fourth part first aid measures-skin contact: eye contact: inhalation: leave the scene quickly to the fresh air. Keep the respiratory tract unobstructed. If you have difficulty breathing, give oxygen. If breathing stops, give artificial respiration immediately. Doctor. Intake: Part V: Fire prevention measures-hazard characteristics: combustible gas. Mixing with air will form an explosive mixture. Contact with heat source, spark, flame or oxidant to burn and explode. Exposure to air or peroxide under light conditions will produce potential explosion hazards. Gas is heavier than air, and can spread to a relatively far place at a lower place, and it will catch fire when it meets a fire source. In case of high heat, the internal pressure of the container rises, which is in danger of rupture and explosion. Harmful combustion products: carbon monoxide and carbon dioxide. Fire extinguishing method: cut off the gas source. If the gas source cannot be cut off, it is not allowed to put out the leaking flame. Spray water to cool the container, and if possible, move the container from the fire to an open place. Container. Extinguishing agent: atomized water, insoluble foam, dry powder, carbon dioxide, sand. Part VI: Emergency treatment of leakage-emergency treatment: employees will leak the polluted area to upwind, isolate it, strictly restrict access and evacuate quickly. Cut off the fire. It is recommended that emergency personnel wear self-contained positive pressure breathing apparatus and anti-static work clothes. Cut off the possible source of leakage. Industrial coating or adsorption/absorbent covers the sewer and other places near the leakage point to prevent gas from entering. Reasonable ventilation and accelerated diffusion. Spray water thinner. Build a dike or dig a hole to contain a lot of waste. Leaked containers should be properly treated, repaired and tested before use. Part VII: Operation, Disposal and Storage-Precautions for operation: Closed operation and full ventilation. Operators must be specially trained and strictly abide by the operating procedures. Operators are advised to wear self-priming filter gas masks (half masks), chemical safety glasses, anti-static work clothes and chemical gloves. Stay away from kindling and heat sources, and smoking is strictly prohibited in the workplace. Use explosion-proof ventilation system and equipment. Prevent the gas in the workplace from leaking into the air. Avoid contact with oxidants, acids and halogens. In the process of transfer, cylinders and containers must be grounded and bridged to prevent static electricity. Handle carefully to prevent damage to cylinders and accessories. Variety and quantity of corresponding fire fighting equipment and leakage emergency treatment equipment. Storage: Store in a cool and ventilated warehouse. Stay away from fire and heat sources. The reservoir temperature should not exceed 30℃. Should be stored separately from oxidant, acid and halogen, and should not be mixed. Explosion-proof lighting and ventilation facilities. Disabled mechanical equipment and tools are prone to sparks. The storage area should be equipped with emergency treatment equipment for leakage. Section 8: Contact Control/Personal Protection-China occupational exposure limits MAC(MG/M3): The MAC(MG/M3) of the former Soviet Union has not been formulated yet: BR/& gt；; TLVTN: TLVWN not established: monitoring method not established: engineering control: production process is closed and fully ventilated. Respiratory system protection: When the concentration in the air exceeds the standard, it is recommended to wear a self-priming filter gas mask (half mask). Eye protection: Wear chemical safety glasses. Physical protection: wear anti-static work clothes. Hand protection: Wear gloves to prevent chemicals. Other protection: Smoking is strictly prohibited in the workplace. When entering a confined space such as a water tank or working in a high concentration area, someone must be supervised. Part IX: Physical and chemical properties-main ingredients: pure appearance: colorless gas with special ether smell. PH value: melting point (℃):- 14 1.5 boiling point (℃):-23.7 relative density (water = 1): 0.66 relative vapor density (air =1):1. Molar heat: 1453 critical temperature (℃): 127 critical pressure (MPa): 5.33 octanol/water partition coefficient logarithmic value: no data flash point (℃): meaningless ignition temperature (℃): 350 lower explosive limit% (v/v): 27.0 lower explosive limit%. Main uses: used as refrigerant, solvent, extractant, catalyst and polymer stabilizer. Other characteristics: part x: stability and reactivity-stability: incompatibility: strong oxidant, acid, halogen. Conditions to avoid contact: polymerization hazards: decomposition products: XI part: toxicology introduction-acute toxicity: LD50: no data; LC50: 308,000 mg/m3 (inhaled by rats); Subacute and Chronic Toxicity: Stimulation: Sensitization: Mutagenesis: Teratogenesis: Carcinogenesis: Section 12: Ecological Data-Ecological Toxicity:. Part XIII: Waste Disposal-Waste Nature: Waste Disposal Method: Please refer to national and local regulations before disposal. Suggestions on incineration treatment. Discarding notice: Part 14: Transport information-dangerous goods code: 2 1040UNNo. : 1033 packing label: packing category: O52BR/ > packing: steel cylinder; Ordinary wooden cases outside frosted glass bottles or threaded glass bottles; Ordinary wooden box outside ampoule. Precautions for transportation: gas cylinders must be worn. The bottle on the helmet is only for transportation. The cylinder is roughly flat, and the bottles should be in the same direction and cannot cross; The height of the fence shall not exceed the board of the vehicle, and it shall be fastened with triangular wooden mats to prevent rolling. Transport vehicles should be equipped with corresponding varieties and quantities of fire fighting equipment during transportation. The bill of lading for the exhaust pipe of this product vehicle must be equipped with a flame retardant device, and it is forbidden to use mechanical equipment and tools that are easy to generate sparks for loading and unloading. Non-oxidant, acid, halogen and edible chemicals are mixed and transported. It should be transported in the morning and evening in summer to prevent sun exposure. Stay away from fire and heat sources during stopovers. According to the main roads, it is forbidden in residential areas and densely populated areas. When transporting by rail, it is forbidden to slip. Part 15: regulatory information-regulatory information Regulations on the Safety Management of Hazardous Chemicals (promulgated by the State Council in February 2006 1987), detailed rules for implementation (No.Lao [1992]677) and Regulations on the Safe Use of Chemicals in the Workplace ([/kloc) Part XVI: Other Information-References: Guidance Department: Data Auditing Unit: Description: Other Information: ][DME supplements known diethyl ether, abbreviated as DME, when the atmospheric or pressurized gas in diethyl ether is colorless liquid with slight odor. The relative density (20℃) is 0.666, the melting point is-14 1.5℃, and the boiling point is -24.9℃. At room temperature, when the vapor pressure is about 0.5MPa, it is similar to LPG. Alcohol, ether, acetone, chloroform, etc. Soluble in water and various organic solvents. The heat of combustion of combustible faint flame (natural gas) is 1455kJ/mol. DME is inert, easy to automatically oxidize at room temperature, non-corrosive and non-carcinogenic, but it is decomposed into methane, ethane and formaldehyde by radiation or heating. Dimethyl ether is an ether homologue, but it can't be used as anesthetic ether, so its toxicity is low. Can dissolve various chemicals; Because of its compression, condensation, evaporation and solubility in various polar or nonpolar solvents, it is widely used in spray products to replace freon refrigerants and solvents, and can also be used in chemical synthesis. As a new basic chemical raw material, dimethyl ether has many unique uses in medicine, fuel, pesticide and other chemical fields because of its good compressibility, condensation and vaporization. For example, high-purity dimethyl ether can be used instead of CFC aerosol propellant and refrigerant to reduce pollution and destroy the atmospheric ozone layer. Because of its good water solubility and oil resistance, its application range is far superior to that of petrochemical products such as propane and butane. Using methanol as raw material, instead of a new production of formaldehyde, formaldehyde can significantly reduce production costs and show its advantages in large formaldehyde plants. As a civil gas, its storage and transportation, combustion safety, premixed gas calorific value and theoretical combustion temperature are better than those of liquefied petroleum gas, city gas pipeline peak shaving gas and liquefied gas. It is also an ideal fuel for diesel engines. Compared with methanol-fueled vehicles, there is no cold start problem. It is also prepared from olefins in the future 1. DME can also replace diesel as fuel. At present, the main problem to be solved is to modify corrosive plastic materials with DME and diesel engine oil. At present, dimethyl ether is mainly used as propellant, refrigerant and foaming agent. The second is used as a chemical raw material for the production of various organic compounds. Such as dimethyl sulfate, alkyl halide, N, N- dimethylaniline, methyl acetate, acetic anhydride, dimethyl carbonate, dimethyl sulfide, dimethyl ether, glycol ether series, etc. Dimethyl ether is easy to compress and store, with high combustion efficiency and little pollution. It can replace coal gas and liquefied petroleum gas as civil fuel. On the other hand, dimethyl ether has a high cetane number and can be directly used as a fuel to replace diesel vehicles. Dimethyl ether, as a clean fuel, has great potential and has been widely concerned at home and abroad. 1 Market analysis at home and abroad 1. 1 Market analysis The world's dimethyl ether production is mainly concentrated in the United States, Germany, the Netherlands and Japan. In 2002, the global output (excluding China, with a total capacity of 208,000 tons/year, the same below) was150,000 tons, and the capacity utilization rate was 72%. The main foreign producers of dimethyl ether are American Dopnt company AKZO Holland, German DEA company and United Rheinland Lignite Fuel Company, among which German DEA has the largest production capacity of 65,000 tons/year. Name of major dimethyl ether manufacturers in the world: series capacity (10,000 tons/year) 1Dopnt (USA) 3.02DEA (Germany) 6.53 Rhine lignite fuel (Germany) 3.04AKZO (Netherlands) 3.05 Sumitomo Corporation (Japan)/kloc-0 1.06DEA (Australia) 65438. Kloc-0/.0 Total 20 Dimethyl Ether Development Company (a consortium composed of Total Fina Elf and 8 Japanese companies) plans to build 2,500 tons/day of commercial dimethyl ether equipment. Toyo Engineering Company has completed the feasibility of building a single household in the Middle East, and the 2.5 million tons/year dimethyl ether plant has passed the verification. It is estimated that the equipment will be completed in 2005-2006. BP, Natural Gas Authority of India and Indian Petroleum Company will invest 600 billion households to build 65.438+0.8 million tons of dimethyl ether commercial production equipment to replace naphtha, diesel oil and liquefied petroleum gas. Construction began in 2002 and will be put into use in 2004. Australia and Japanese consortium (Mitsubishi Gas Chemical Company, Japan, Mitsubishi Heavy Industries, Itochu Corporation) jointly build a large-scale dimethyl ether plant with a capacity of1.4-24,000 tons/year, and it is planned to put into operation in 2006. Dimethyl ether is used as solvent and aerosol propellant in the main consumption fields, and it is also consumed in other aspects. In 2002, the global consumption of dimethyl ether was 6.5438+500,000 tons/year, and it is estimated that the demand in 2005 will be about 200,000 tons/year. Dimethyl ether is an excellent, safe and clean chemical product, and its development prospect is generally optimistic. More importantly, as a new, clean and civil vehicle fuel, it is regarded as a good substitute for diesel or liquefied petroleum gas/natural gas, which will greatly increase the demand for fuel. There are 4 million LPG vehicles, 4 million ethanol vehicles,/kloc-0.0 million CNG vehicles and some methanol vehicles in the world. In the United States, the number of vehicles using alternative fuels in the United States in 2000 is expected to be 420,000 by 2005, and the number of vehicles using alternative fuels (LPG and CNG) in the United States will reach165438+3.3 million by 20 15, and will reach 5.5 million by 20 15. The consumption of alternative fuels is about 6,543.8+0,000 tons, and then (352× 654.38+0.06 gallon gasoline equivalent), so the total fuel consumption accounts for about 0.2%. If the proportion of alternative fuels in the United States is increased to 5%, its demand will reach 250,000 tons, which shows that the alternative fuels in the market prospect are considerable. Asia is the fastest growing region of diesel consumption in the world. According to foreign research institutions, the demand for dimethyl ether as an alternative fuel in Asia will reach 300,000 tons in 2005. It can be seen that dimethyl ether will become the main alternative fuel of diesel because of its incomparable advantages over other alternative fuels, and its market prospect is immeasurable. 1.2 domestic market analysis In recent years, China, which produces dimethyl ether, has developed rapidly. At present, there are more than ten manufacturers. In 2002, the total production capacity was 3 1.08 million tons/year, and the output was about 200 million tons, with a low capacity utilization rate of about 63%. Main dimethyl ether producers and their production capacity (unit: 10,000 tons/year) Name of production enterprise series production capacity 1 Jiangsu Wuxian Chemical Synthesis 20002 Zhongshan Kaida Fine Chemical Co., Ltd. 50003 Chengdu Huayang Weiyuan Natural Gas Plant 2000 Petrochemical 4 Shanghai Research Institute 8005 1 0006 Jiangsu Kunshan Shaanxi New Gas Appliance Company 50007 Mengcheng County, Anhui Province 25008 Zhejiang Zhuji Xinya Fertilizer Company Ltd.25001KLOC-0/Shanghai Shenwei Aerosol Company 100 12 Shandong Jiutai Chemical Technology Co., Ltd.500013 Hubei Tian Industrial Co., Ltd./. The main projects or plans under construction are as follows: In April of 20001year, Shaanxi Xinran gas appliance Co., Ltd. signed a project agreement to jointly develop "200,000 tons/year dimethyl ether ultra-clean fuel from coal", with a total investment of 203 billion RMB, 90% of which came from the United States. The coal-based dimethyl ether project in Ningxia is 830,000 tons/year, with a planned investment of 478 billion yuan. It plans to use foreign capital and has reached a joint venture agreement with Canadian company Jimmy Knight, relying on the technology of the US Air Force. Sichuan Luzhou Natural Gas Company has built a 65.438 million tons/year dimethyl ether plant and a second 65.438 million tons/year dimethyl ether plant by two-step method, and has started construction. Shandong Linyi Minglu Chemical Co., Ltd. is building a 30,000-ton/year dimethyl ether plant, adopting the self-developed gas-liquid two-step process technology. year/>； The annual output and equipment use of Shandong Huaxing Group is a two-step process. Shandong Yankuang Group plans to build a 600,000-ton dimethyl ether plant and introduce one-step dimethyl ether technology. In addition, it is pointed out that there are many local dimethyl ether plants under construction in China, such as Southwest Petroleum and Natural Gas Administration, Xinjiang, Shuangyashan, Heilongjiang, Anniversary Oilfield, Shaanxi Province, Lanzhou City and Anhui Province. Dimethyl ether is mainly used as aerosol, aerosol and spraying propellant in China, and it consumes dimethyl ether 18000 tons every year. Due to the rapid development of aerosol industry, it is estimated that about 30,000 tons of dimethyl ether will be needed in 2005 and 40,000 tons in 20 10. It is also used for the synthesis of fine chemical products such as dimethyl ether and dimethyl sulfate, and the consumption is about 1 1000 tons. Dimethyl ether and liquefied petroleum gas are similar in nature and easy to store and compress, so it can replace natural gas, coal gas and liquefied petroleum gas as civil fuel. In 2002, the apparent consumption of liquefied petroleum gas in China was162,000 tons, while the import volume in China was 1990 tons. Since 2002, the import of liquefied petroleum gas has reached 6.26 million tons. Dimethyl ether, if the price is right, assuming that dimethyl ether replaces imported liquefied petroleum gas, at the current import volume, it needs about 6,543,800,000 tons of fuel-grade dimethyl ether. With the continuous improvement of people's living standards, the demand for household fuels will increase greatly, especially clean energy such as natural gas, dimethyl ether and liquefied petroleum gas. Therefore, the development prospect of dimethyl ether as fuel for civil use is very broad. Because dimethyl ether has excellent fuel performance, convenience, cleanliness, high cetane number, good power performance and little pollution, it is liquid under a little pressure and easy to store. Alternative fuel vehicles are diesel, liquefied gas, natural gas, methanol and ethanol. Unparalleled comprehensive advantages. In 2002, the diesel consumption was 76.62 million tons, which increased rapidly year-on-year. It is estimated that the consumption will reach 82.9 million tons in 2005 and about 10 1000 tons in 2006. As a good alternative fuel for diesel, dimethyl ether has an annual interest rate of 5%. In 2005, dimethyl ether was about 5.53 million tons, and the whole process of 20 10 was about 6.74 million tons. In short, it is estimated that the demand for dimethyl ether in China in 2005 will be about 50,000-60,000 tons, including the demand for aerosols and chemicals. The consumption of dimethyl ether as alternative fuel mainly depends on the supply of dimethyl ether. If the price drops, dimethyl ether can compete with diesel or liquefied petroleum gas. It is believed that the consumption of dimethyl ether as fuel is growing rapidly and the market scale is quite amazing. Technical analysis There are two production methods of dimethyl ether: one-step method and two-step method. Dimethyl ether was synthesized from methanol in synthesis gas by one-step, one-step and two-step methods, and then the dimethyl ether was dehydrated by raw gas. ● In the next step, the synthesis gas produced by legal conversion or gasification enters the synthesis reactor from natural gas and synthesis gas, and methanol synthesis and methanol dehydration reaction are carried out in the reactor. At the same time, the reaction product of step 2 is a mixture of methanol and dimethyl ether, and the mixture is returned to the synthesis reactor through a distillation separation device, dimethyl ether and unreacted methanol. Generally, two kinds of multi-step bifunctional catalysts are physically mixed. One is used for methanol synthesis, such as Cu-Zn-Al (O)-based catalysts, BASFS3-85 and ICI-5 12. Methanol dehydration catalysts include alumina, porous silica-alumina, Y zeolite, ZSM-5 zeolite, mordenite and so on. ● Two-step method is divided into two steps, that is, the solid catalyst DME in methanol dehydration is synthesized from methanol synthesis gas. γ-Al2O3/SiO2 and ZSM-5 molecular sieves are widely used in dehydration in China. The reaction temperature is controlled at 280 ~ 340℃, the pressure is 0.5 ~ 0.8 MPa, the conversion rate of methanol is 70 ~ 85%, and the selectivity of dimethyl ether is greater than 98%. Compared with the two-step method, the methanol synthesis process without one-step synthesis of dimethyl ether has the advantages of simple process, less equipment, less investment and low operating cost, thus reducing the production cost of dimethyl ether and improving the economy. Therefore, one-step synthesis of dimethyl ether is a hot topic at home and abroad. Representative steps of foreign development: NKK technology of American Air Chemical Products Company and Japanese technology during Topsφe process in Denmark. Two-step synthesis of dimethyl ether is the main production technology of dimethyl ether at home and abroad. Using legally refined methanol as raw material, the consumption is small, the by-product of dehydration reaction, the purity of dimethyl ether is 99.9%, the technology is mature, the device has wide adaptability and the treatment is simple. It can be directly built in the methanol production plant, and other non-methanol production plants with good public facilities are also built in it. However, this method needs to go through the processes of methanol synthesis dehydration, methanol rectification, methanol and dimethyl ether rectification, which takes a long time, so it has a large equipment investment. However, the vast majority of large-scale construction projects with two-step dimethyl ether technology announced abroad show that the two-step method has strong comprehensive competitiveness. 2. 1 main foreign technology (1)Topsφe process Topsφe synthesis gas one-step method is a new technology specially developed for natural gas raw materials. The gasification part of the selection process is autothermal reforming (ATR). The refractory lining added to the autothermal reformer includes a high-pressure reactor and a three-part catalyst bed chamber. A built-in adiabatic reactor with multi-stage cooling stage is used to obtain high conversion between CO and CO2 to synthesize dimethyl ether. Mixed bifunctional catalyst for methanol synthesis and dehydration to dimethyl ether. Using spherical shape, a single set of dimethyl ether synthesis reactor can reach 7200 tons/day dimethyl ether. The operating conditions of 4.2MPa and 240 ~ 290℃ were selected. At present, the process has not yet been built into a commercial chemical plant. 1995, Topsφe established a 50 kg/day pilot plant in Copenhagen, Denmark, and used it to test the performance of this method. (2) New Technology of Liquid Dimethyl Ether for Air Products (LPDMETM) Air Products Company successfully developed a new technology of liquid dimethyl ether, referred to as LPDMETM. The main advantage of LPDMETM process is to use slurry bubble bed reactor to abandon the gas phase of traditional fixed bed reactor. After the catalyst particles become fine powder, inert mineral oil slurry is formed. Crude synthesis gas is injected and bubbled from the bottom under high pressure, and solid catalyst particles are fed with gas to achieve full mixing. Mixing mineral oil makes the operation more comprehensive and isothermal, and it is easy to control the temperature. DME synthesis reactor has built-in cooling pipe, which is used to generate steam while heating. The catalyst in the slurry reactor is easy to load and unload and does not need to be shut down. In addition, due to the isothermal operation in the reactor, there is no hot spot, and the deactivation rate of the catalyst is significantly reduced. Typical reactor operating parameters: pressure 2.76 10.34MPa, recommended 5.17 MPa; Temperature is 200-350℃, and 250℃ is recommended. 5% to 60% of mineral oil in a catalytic amount, preferably 5% to 25% by mass. The method of using co-rich syngas is better than natural gas coal-based syngas. However, natural gas can also be used as raw material to obtain higher yield. Air Products Company owns 15t/ day pilot plant, and the test process is satisfactory, but it is not the construction of large-scale commercial equipment. (3) A New One-step Liquid Process of NKK in Japan In addition to Air Products, NKK in Japan has also developed a new technology of one-step synthesis of dimethyl ether from slurry reactor and syngas. Choose natural gas, coal, liquefied petroleum gas and other raw materials. The first step of the process is gasification, and the synthesis gas is cooled and compressed to 57MPA, and CO2 is removed in the CO2 absorber. After the crude synthesis gas enters the bottom of the reactor through the decarbonization hot activated carbon adsorption tower, the sulfur-containing compounds are removed at 200℃. In a reactor with dimethyl ether, methanol and carbon dioxide, the slurry in the synthesis gas of the catalyst bubbles together with mineral oil. The product is cooled in the reactor and fractionated into dimethyl ether, methanol and water. Unreacted synthesis gas is recycled to the reactor. After fractionation, high-purity crude products can be obtained from the top of dimethyl ether (95% 99%) and the bottom of methanol, dimethyl ether and water. NKK technology has been established in Niigata, using a semi-industrial plant for dimethyl ether synthesis with a production capacity of10,000 tons/year. 2.2 Cases Domestic technology and scientific research spread all over the country in the 1990s, with the development of methanol vapor process (two-step method) production technology and catalyst, and the rapid establishment of industrial production equipment. In recent years, with the upsurge of dimethyl ether construction, China's two-step dimethyl ether technology has been further developed, and the technology has approached or reached the international advanced level. Shandong Jiutai Chemical Technology Co., Ltd. (formerly Linyi Minglu Chemical Co., Ltd.) successfully developed a proprietary production process of catalytic dehydration liquid dimethyl ether composite acid, and built a 5000-ton/year production device. After one year's practice, it is proved that this technology is mature and reliable. The company's 230,000 tons/year device will also be put into production. Shandong Jiutai dimethyl ether technology has passed the Science and Technology Department of Shandong Province and is recognized as reaching the international level. A particularly complex technology of acid-liquid phase dehydration and condensation catalyst separation was developed, which overcame the main disadvantages of high cost of one-step synthesis and gas dehydration and continuous reaction dehydration at the time of investment, reduced equipment corrosion and investment in purification equipment, with a total recovery rate of 99.5%, a purity of not less than 99.9% and a production cost greater than that of gas phase reduction. In August 2003, a two-step dimethyl ether production plant was successfully developed in cooperation with LTH of Toyo Engineering Company of Japan. The process of the equipment is reasonable, the operating conditions are optimized, and it has the characteristics of high purity, low material consumption and low energy consumption. In terms of technology, product quality and automation hardware are at the advanced level in China. In recent years, the development of dimethyl ether synthesis technology in China is also very positive, and some research institutions and universities have made great progress. The Compound Fertilizer Plant of Portland Pioneer Maryland College * * * conducted a small-scale study on 5mL dimethyl ether synthesis gas, focusing on process research, catalyst preparation, catalytic activity and service life. The experiment has achieved good results: CO conversion rate >; 85%; Selectivity >; 99%。 Two long-term experiments (500H, 1000H) show that the developed catalyst has good stability in industrial raw material synthesis gas; Organic matter >: selectivity of 97% dimethyl ether; & gt The conversion rate of carbon monoxide is 75%; The purity of dimethyl ether product is more than 99.5%; The yield of dimethyl ether is 98.45%. The composite catalyst system of dimethyl ether direct synthesis gas in Dalian Institute of Chinese Academy of Sciences was systematically studied and screened. The catalysts SD 219-Ⅰ, SD 219-Ⅱ and SD 219-Ⅲ have good catalytic performance. The conversion rate of CO reaches 90%, and the selectivity of dimethyl ether in oxidized organic matter is close to 100%. Tsinghua University also studied one-step dimethyl ether in slurry bed reactor. LP and Al2O3 bifunctional catalysts are used. Under the conditions of 260-290℃ and 4-6MPa, the selectivity of dimethyl ether is 90-94% under the unidirectional CO conversion of 55%-65%.