It is an important organic chemical raw material and high-quality fuel. Mainly used in the manufacture of formaldehyde, acetic acid, methyl chloride, methylamine, dimethyl sulfate and other organic products. It is also one of the important raw materials for pesticides and medicine. Methanol can also be used as fuel instead of gasoline.
Methanol is the main component of fake wine. Excessive consumption can lead to blindness and even death!
Foreign production situation and analysis
In foreign methanol technology, 92% of methanol is made of natural gas and 2. 3% comes from coal. Therefore, the methanol technology of foreign companies focuses on producing methanol from natural gas. The advanced methanol production technologies widely used in the world mainly include: DAV Y (formerly I. C. I), O PSO E, U hde and L u rgi methanol technologies, etc. The consumption and energy consumption of different methanol technologies are not much different, the main difference is that the main equipment types used in methanol synthesis tower are different.
Technical characteristics of 1 The advantage of 1 DAV Y methanol DAV Y low-pressure methanol synthesis technology lies in its excellent low-pressure methanol synthesis catalyst, and the synthesis pressure is 5. 0 ~ 100 MPa, and the synthesis pressure of large methanol production plant is 8 ~ 100 MPa. There are three types of synthetic towers: first, the quench synthetic tower, with a large single tower production capacity and an outlet methanol concentration of about 4 ~ 6% VO L, and second, the methanol synthetic tower with internal heat exchange and cold tubes. A water-tube synthetic tower was also developed. Distillation usually adopts double towers and sometimes three towers, considering the setting of steam system. Steam system: divided into three levels: high pressure 10.5M Pa and medium pressure 2. 8M Pa and low pressure 0. 45M Pa。 The waste heat generated by conversion and converter flue gas waste heat are used to generate 10 high-pressure superheated steam. 5M Pa and 5 10℃. The high-pressure superheated steam is used to drive the steam turbine of the synthetic compressor, and the extracted medium-pressure steam is used in the device.
1.2 L u rgi methanol technology the synthesis of L u rgi company has its own characteristics, that is, it has its own patent for synthetic tower. It is characterized in that the synthesis tower is tubular with by-product steam, Lμrgi synthesis catalyst in the tube, boiler water between the tubes, and by-product 3. 5-4.0 MPa saturated medium pressure steam. Because the diameter of large-scale devices, such as the synthetic tower of 2000M TPD is too large, two synthetic towers are often connected in parallel. If the scale is large, the cold pipe or hot pipe synthesis tower is connected in series after the tubular synthesis tower, or two synthetic towers can be used in parallel. The rectification of L 'Urgi process adopts three-tower rectification or three-tower rectification followed by a recovery tower in series. Two-tower distillation is sometimes used. The reboiler heat source of pre-distillation column and pressure distillation column in the process of three-tower rectification comes from the waste heat of reformed gas. Therefore, distillation consumes little low-pressure steam.
1.3 methanol technical characteristics of Xiang PSO E Xiang PSO E company is the main patented technology supplier and catalyst manufacturer in the synthetic ammonia and methanol industry, and its methanol technical characteristics are mainly manifested in the following aspects: the methanol synthesis tower adopts BWR synthesis tower (tubular by-product steam) or CMD multi-bed adiabatic synthesis tower. Its technological characteristics are: using axial adiabatic bed, installing heat exchanger between towers, and preheating boiler feed water or circulating hot water in saturation system by using waste heat. The inlet temperature of the tower is 220℃. The single-pass conversion rate is high, the catalyst volume is small, the structure of the synthesis tower is simple, and the single-series production capacity is large. The synthesis pressure is 5. 5.0~ 10. Optimize according to the production capacity of the factory. The methanol plant with a daily output of 2,000 tons has a synthesis pressure of about 8M Pa. Adopt three-tower or four-tower (including recovery tower) process technology.
Technical characteristics of 1 4 TEC methanol synthesis process adopts IC I low pressure methanol technology. Adopt the technology of L u rgi company for rectification. Ic 1 low pressure methanol synthesis catalyst was used in the synthesis. Synthetic tower: MRF- Z synthetic tower (multi-layer radial synthetic tower) using TEC, the outlet methanol concentration can reach 8% VO L, and the resistance drop of synthetic tower is small, which is 0. 1mpa. Waste heat from methanol synthesis is used to produce 3. 5-4.0 MPa medium pressure steam can be used as process steam or superheated steam for turbine drive.
1.5 technical characteristics of methanol of Mitsubishi heavy industries Mitsubishi methanol technology is similar to the I. C. I process, with the unique structure of super methanol synthesis tower. The synthesis pressure is related to the production capacity of methanol plant. The daily output of methanol is 2000 tons, and the synthesis pressure is about 8. 0M Pa。 The characteristics of super methanol synthesis tower are: using double sleeves, uniform catalyst temperature, high single-pass conversion rate, and the highest outlet concentration of synthesis tower can reach14% VO L. By-product 3. The medium pressure steam of 5-4.0 MPa can reach 8-10% VO L. Compared with the traditional process, the circulation of the synthesis system is greatly reduced, and the consumption of make-up gas is the least. According to the setting of steam system, two or three towers are used for distillation.
1 methanol technology. 6 Wood Company adopts I. C. I low-pressure synthesis process and catalyst, and the synthesis pressure of methanol plant in 2000 days is 8. 0M Pa。 Synthetic tower: Wood Company adopts improved air-cooled diamond reactor, isothermal synthetic tower and cold tube synthetic tower. The single series production capacity of arc synthetic tower (multi-axial radial synthetic tower) of CA SAL E company can reach 3000M TPD. Comprehensive waste heat recovery method: preheating boiler feed water, low equipment investment. Isothermal synthesis tower: shell-and-tube synthesis tower with by-product medium pressure steam. The medium pressure steam pressure is 3. The maximum production capacity of a single tower can reach 1200M TPD. High investment in equipment. Cold tube synthesis tower: indirect heat exchange between axial direction and cold tube, and the maximum production capacity of a single tower can reach 2000M TPD. Low equipment investment. 2-tower, 3-tower or 4-tower distillation can be used, and the comparison is as follows: 2-tower distillation, the methanol recovery rate is 98. 5%, while 1 ton methanol consumption 1. 2 tons of low pressure steam. The recovery rate of methanol is 99%. 1 ton methanol consumes 47 tons of low-pressure steam. Four-tower distillation with methanol recovery tower, the methanol recovery rate is 99. 5%, 1 ton methanol consumption 0. 45 tons of low pressure steam.
1.7 Linde's methanol technology is characterized by adopting I. C. I low-pressure synthesis process and catalyst. Helix isothermal synthesis tower with by-product steam. Tube for boiler water, medium pressure steam pressure is 3. 5 ~ 4.0 MPa, so the gas resistance is reduced. The rest is similar to IC I low pressure methanol.
Present situation and analysis of domestic production
3. 1 Major domestic manufacturers
At present, there are 48 methanol production enterprises/KLOC-0, with a total output of 4.8 million tons, output of 2.8 million tons and market demand of 3.9 million tons. It is estimated that the demand for methanol in 2005 will be about 5.5 million tons. There are more than 30 equipment in shutdown or semi-shutdown state, most of which are due to high production cost and low equipment efficiency. Some production equipment with backward technology, outdated equipment and small capacity has shown a general trend of being eliminated.
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Production equipment with coal as raw material; Sinopec Sichuan Vinylon Factory uses acetylene tail gas and natural gas as raw materials; Methanol production enterprises with natural gas as raw materials include Shaanxi Yulin Natural Gas Chemical Company, Daqing Oilfield Methanol Plant, Shaanxi Changqing Oilfield and Sichuan Jiangyou Methanol Plant. The production scale is about 654.38+10,000 tons/year. Most other production units adopt the combined alcohol technology, and the production scale is 654.38+0 ~ 50,000 tons/year. Since 1995, domestic methanol industry has developed rapidly. The raw materials used in the production are mainly synthetic gas produced by the combined methanol method, and the main development factors are the development of new natural gas fields such as Xinjiang, Sichuan and Inner Mongolia. In addition, due to the development and production of domestic methanol downstream products, such as formaldehyde, olefin, acetic acid, methyl ester series, civil/automobile fuel, etc. And the development and production of methanol catalyst researched by Southwest Research Institute of Chemical Technology and Nanhua Company. There are several methanol projects with coal or natural gas as raw materials in the process of declaration and preparation, of which 6 facilities exceed 65438+ 10,000 metric tons/year, and the largest is 600,000 metric tons/year. The total capacity of the proposed plant is 2,654.38+300,000 metric tons/year.
3.2 Market prospect analysis of main downstream products of methanol (formaldehyde, methanol gasoline, dimethyl ether, etc.). The demand for methanol is closely related to the overall economic development. In 20001year, the domestic demand for methanol was 3.5 million metric tons, mainly used for: methanol derivatives accounted for 69%, fuels accounted for 7%, solvents accounted for 5%, medicines accounted for 6.5%, pesticides accounted for 8.5% and others accounted for 4%.
3.3 Domestic Methanol Import and Price Domestic imports a large amount of methanol every year to meet the market demand, and the market price tends to be international. As the domestic consumption market of formaldehyde and acetic acid increases, so does the demand for methanol. Some methanol plants have stopped production or reduced production for various reasons, which cannot meet the demand of the domestic market.
3.4 Market analysis predicts that the demand for methanol will increase substantially in 2005, and it will take some time under the new conditions to benefit from the new capacity in mid-2004. This period may be postponed until mid-2005. It is estimated that more new capacity will be put into use. The total demand for methanol in 2004 was the same as that in 2003. Due to the active sectors unrelated to MTBE, it is expected that the demand for methanol will increase greatly in 2005. The basis for making the change forecast is how much new production capacity is actually put into use during the inspection period, and what impact these new production capacities have on the product prices in the market.
3.5 In the five years after 2004, the production capacity of methanol will exceed180,000 tons. These new capacities are mainly distributed in South America, the Near East and Australia. These areas will become major industrial methanol production and supply centers, and the demand for methanol will increase to 5 million tons per year. In addition to the new methanol production capacity, the existing large-scale methanol production capacity is distributed in North America and Europe. However, if the production is stopped beyond the new capacity, the existing methanol capacity is far from meeting the market demand. Therefore, the existing methanol producers in Central Europe, CIS, India, Southeast Asia and Northeast Asia have a heavy burden.
3.6 Domestic methanol process technology
China is a country rich in coal, and natural gas and coal are more used as methanol raw materials. The output is almost evenly divided. There are two production processes: methanol per unit area and methanol co-production. Co-production of methanol In addition to the co-production of methanol in synthetic ammonia plants, methanol can also be co-produced by using the tail gas of chemical plants or by combining with city gas.
3.6. 1 Domestic methanol gasification technology
The technologies for methanol production from natural gas in China mainly include one-stage steam reforming process and two-stage pure oxygen reforming process of China Chengda Company. China coal-to-methanol technology mainly includes: fixed bed gasification (including L u rgi furnace, Ender furnace and intermittent gasifier), fluidized bed gasification (ash agglomeration) and entrained-flow gasifier. Texaco coal water slurry gasification and Shell pulverized coal gasification were introduced in recent years, among which Texaco gasification was introduced earlier, with more experience, high localization rate and less investment. Shell gasification has no experience.
3.6.2 Domestic gas purification technology
The desulfurization and decarbonization purification of methanol crude gas is the same as that of synthetic ammonia, except that liquid nitrogen washing is not needed. The main purification technologies in China include low-temperature methanol washing, MDEA and NHD, ADA and PDS for desulfurization of hot potash in small and medium-sized devices, PC and MDEA for decarbonization.
3.6.3 methanol synthesis and distillation technology
Since 1986, China has developed low-pressure methanol synthesis and distillation technology. The shell-and-tube by-product steam synthesis tower and double-tower distillation widely used in China are derived from this development. Later, the U-shaped cold-tube synthesis tower was popularized, and the rectification was also developed from two towers to three towers, which could not only produce GB338-2004 refined methanol, but also produce American O-M-232KAA grade refined methanol. Breakthrough progress has been made in the treatment process of alcohol wastewater.
Methanol technology is developing rapidly, and the main trends are as follows:
(1) Production raw materials are shifted to natural gas and hydrocarbon processing tail gas. According to the actual situation of methanol production, using natural gas as raw material can reduce the investment by 50% compared with using solid as raw material; Using acetylene tail gas has more remarkable economic benefits. 90% of the raw materials for methanol production in the world are natural gas, and only 2% are coal. The proportion of coal-to-methanol in China is increasing gradually, which is related to the energy structure of China.
② Large-scale production, with the largest scale of a single series reaching 2.25 million tons &; In 2000, the daily output of OUML in a single season was 7,500 kg. After the scale is expanded, the investment and cost per unit product can be reduced.
③ Fully recover the heat of the system. Produce steam with economic pressure to drive compressor, boiler feed water pump, steam turbine and circulating water pump to realize comprehensive utilization of heat energy.
④ A new methanol synthesis tower with by-product medium-pressure steam is adopted to reduce energy consumption.
⑤ Energy-saving technologies, such as hydrogen recovery technology, pre-conversion, process condensate saturation technology and combustion air preheating technology, are adopted to reduce methanol consumption.