The development of methanol gasoline abroad has mainly gone through three stages: research and development, demonstration and popularization, and decline. Due to the two oil crises in 1970s, Germany, Sweden, the United States and so on have successively carried out research on methanol as an alternative energy source. In 1980s, driven by improving the quality of atmospheric environment, methanol was listed as a clean fuel, which was further demonstrated and popularized. But after the end of 1980s, methanol gasoline was gradually replaced by ethanol gasoline in Europe. After 1998, methanol-fueled vehicles and methanol fuel in the United States also began to decrease. The fundamental reason why people are unwilling to accept methanol gasoline is its many shortcomings, including: methanol is toxic and easy to cause personal injury, which can lead to blindness and even death in serious cases; Strong corrosiveness, difficult to detect in a short time, shortening the service life of the car; The calorific value is only half that of gasoline, which limits the driving distance of vehicles; Methanol gasoline is difficult to start cold in winter, but it is prone to "gas resistance" in summer. Unconventional emissions such as formaldehyde in methanol automobile exhaust are much higher than ordinary gasoline, and formaldehyde is a strong carcinogen. At the same time, the economic loss of competitiveness also accelerated the decline of methanol gasoline. According to the investigation and analysis of the development process of methanol gasoline abroad, it is suggested that methanol gasoline should be banned in China. Even if methanol gasoline is compulsory, all aspects should be fully prepared. In fact, the implementation of methanol gasoline in China will ultimately benefit the methanol producers in the Middle East and New Zealand, not the methanol industry in China.
Key words: methanol gasoline, recession, alternative energy, ethanol gasoline, corrosiveness, cold start, formaldehyde
1 preface
Methanol is a liquid fuel that can burn cleanly, and its raw material is usually natural gas, coal or biomass. The development and application of methanol gasoline abroad began with the second oil crisis in 1970s. From the perspective of alternative energy, Germany, the United States, Japan and other countries have invested manpower and material resources in the research and development of methanol fuel and methanol vehicle supporting technology, but later for various reasons, methanol gasoline has not been widely used in practice.
2 General situation of methanol gasoline development abroad
The development of methanol gasoline abroad has mainly gone through three stages: research and development, demonstration and popularization, and decline.
2. 1 R&D stage
Due to the "oil crisis", many countries are actively looking for energy sources to replace oil for energy security. As a liquid fuel, alcohol fuel is similar to traditional gasoline and diesel in storage, transportation, distribution and use, while methanol is rich in raw material resources and clean in combustion, so it has attracted the attention of the international community. Germany, Sweden, the United States and other countries have successively carried out research on alternative energy sources of methanol. For example, since 1975, Sweden has organized many projects to study methanol fuel production technology and methanol fuel vehicles. From 65438 to 0976, the first International Conference on Alcohol Fuels (ISAF) was held in Sweden to promote the development of alcohol fuels (mainly methanol and ethanol). In the late 1970s and early 1980s, the German government organized a fleet of more than 1000 M 15 vehicles to conduct large-scale research and demonstration across the Nordic border.
2.2 Demonstration and promotion stage
In the 1980s, although oil prices fell, the global demand for air quality increased. It is found that alcohol fuel can not only replace petroleum, but also the conventional emission of automobile exhaust using alcohol fuel is lower than that of gasoline and diesel vehicles, which is more beneficial to the environment. Driven by improving the quality of atmospheric environment, methanol is listed as a clean fuel, which has been further demonstrated and popularized.
Sweden began to introduce methanol alternative fuel M 15 on a large scale in 1980, and it is planned to make the replacement amount of methanol reach 10% of gasoline and diesel consumption in10.
In order to encourage the development of alternative fuels and improve the atmospheric environment, the US Congress passed three legislative bills within five years: 1988, and President Reagan signed the Alternative Vehicle Fuel Act; 1990, President Bush signed the Clean Air Act Amendment; The energy policy bill was signed on 1992 [1]. Its main contents are as follows: (1) preferential policies for tax reduction and exemption for producing clean alternative fuel vehicles and using alternative fuels; Require cities to implement projects to purify the urban environment; Government departments take the lead in using methanol vehicles. These bills have promoted the development of methanol fuel in terms of policies and funds.
During the 20 years of 1978- 1998, California Energy Commission started the methanol vehicle demonstration project in California. This is the largest methanol vehicle demonstration project in the world. 65,438+08 kinds of methanol vehicles were displayed. At the end of 1970s, special methanol vehicles were tested, but too few gas stations were promoted. In 1980s, we turned to the development of Flexible Fuel Vehicle (FFV) which can burn both M85 methanol and gasoline to solve the problems of refueling, cold start and methanol flame in transit. From the mid-1980s to the end of 1990s, there were 65,438+05,000 methanol vehicles and hundreds of methanol buses and school buses in California. At that time, methanol FFV cars produced by European, American and Asian automobile factories were mainly assembled with cheap ready-made automobile parts, with methanol fuel sensors, methanol fuel pumps, nozzles and other parts added, and some materials of the fuel system were replaced. At that time, there were four kinds of FFV specially produced in the market: Ford Taurus (model 1993- 1998), Chrysler Dodge Spirit/ Plymouth Acclaim (model 1993- 1994), Chrysler Concorde /Interpid (model 6544). The increased cost of these vehicles is borne by the government and does not increase the extra burden on consumers. Ford's Taurus methanol car is even $345 cheaper than the same type of gasoline car. By 1996, Ford Taurus became the only mass-produced methanol vehicle on the American automobile production line.
1988, California Energy Commission established California methanol fuel reserve, signed lease agreements for 10 with oil companies such as Amoco, Exxon, Mobil and Shell, built underground methanol storage tanks and 60 methanol gas stations, and assisted in establishing 45 methanol gas stations convenient for private vehicles to refuel. From the mid-1980s to the mid-1990s, except California, 15 states in the United States established methanol gas stations.
The first commercial M85 vehicle reached its peak in 1997 after it was put into production in 1987. There are 2. 1× 104 methanol vehicles in operation in the United States, and more than 100 methanol filling stations have been built.
2.3 recession stage
In Germany, Sweden and other European countries, the application of methanol gasoline was initially promoted by M 15, but after the end of 1980s, methanol gasoline was gradually replaced by ethanol gasoline. After 1998, methanol-fueled vehicles and methanol fuel in the United States also began to decrease. On the one hand, after the lease of 10 year expires, most methanol gas stations owned by oil companies turn around and come back to refuel. Without the support of gas stations, methanol vehicles have no place to refuel, and FFV vehicles must refuel. On the other hand, the methanol demonstration vehicles that were put into the market before were gradually eliminated. By 2003, M85 almost completely withdrew from the market, and major automobile manufacturers stopped developing and producing methanol-fueled vehicles. The three major American automobile companies-GM, Ford and Chrysler even publicly stated in the user manual that the damage of vehicles using methanol gasoline is not covered by the automobile warranty. On August 29th, 2008, the California Air Resources Board promulgated the California Regulations on New Formulated Gasoline, and the first oxygenate in the list of new formulated gasoline is methanol.
After 1998, great changes have taken place in American methanol industry. At that time, there were 18 methanol plants in the United States with an annual output of 20×108 gal (1gal = 3.785l, the same below). By 2005, there were only five methanol plants with an annual output of 300× 104gal in the United States, and methanol fuel was gradually ignored.
3 Reasons for the decline of methanol gasoline abroad
At present, methanol gasoline has basically declined abroad. As a fuel, methanol experienced the process of government support, demonstration and promotion, and was finally restricted or banned in the United States, Sweden, Germany and other countries. In addition to the political and economic situation of each country at that time, the defect of itself as fuel is the most fundamental reason.
3. Many shortcomings exposed by1methanol gasoline are the fundamental reasons why people are unwilling to accept it.
The main defects of methanol include: ① methanol is toxic, and careless use of methanol gasoline can easily cause harm to producers, gas station personnel, users and maintenance personnel, and even lead to blindness and even death in serious cases. (2) Methanol is corrosive, which will cause a lot of trouble in the process of storage and use. It will corrode the metal and alloy materials of oil storage tanks, refueling guns, automobile fuel tanks and oil circuits, easily cause the expansion of the elastomer and gasket in the engine, gradually and imperceptibly damage the automobile engine in a short time, and shorten the service life of the automobile. The corrosiveness of methanol will also be shown in low proportion methanol fuel [3]. ③ The calorific value of methanol is only half that of gasoline, which greatly limits the driving distance of vehicles. (4) According to the evaporation and combustion characteristics of methanol, the boiling point of pure methanol is fixed at 64℃, and the latent heat of evaporation is high, which is 1 178kJ/kg, while gasoline is only 330-420kJ/kg, so methanol gasoline is not easy to evaporate in winter, and it is difficult to start cold. In summer, methanol gasoline shows an unusually high vapor pressure, which is prone to "gas resistance". ⑤ Methanol may be incompatible with gasoline detergent [3].
Traffic management departments in Los Angeles and Seattle gave up methanol projects because of the high corrosiveness of methanol fuel. Los Angeles traffic management officials announced that the main reason for the failure of their methanol pollution prevention project was that methanol vehicles needed frequent maintenance. After five years of experiments, officials of the Seattle Metro Transportation Department canceled the methanol vehicle demonstration project. The test results of the project show that when the bus travels 6× 104-7× 104 miles (1 mile = 1609.344 meters), serious engine failure will occur, which is mainly caused by the corrosiveness of fuel.
Carmakers are also opposed to mixing methanol with gasoline. After 1998, automobile manufacturers stopped producing methanol vehicles. The reason they explained was that although methanol automobile technology was mature, there was no market and users were unwilling to use it. 199865438+February, the world fuel specification jointly issued by the World Automobile Manufacturers Organization requires that "methanol is not allowed"; In the new fuel specification in April 2000, it was explicitly required again that "methanol is not allowed".
American oil companies are also reluctant to support methanol gasoline. Although these oil companies once leased some gas stations to the California Energy Commission, they did not undertake the marketing of methanol gasoline. On the contrary, they oppose the use of methanol as an alternative fuel in various public places. Seven American oil companies proposed to build 8 1 methanol gas stations, but by 1996, only 52 were built. Chevron announced the withdrawal of its commitment on 1992; Arco and Shell announced on 1995 that they would not build M85 gas station; When the California Energy Commission asked for reconstruction, other oil companies refused to continue to build methanol gas stations. After the lease term of 10 expires, all the methanol gas stations built by these oil companies will be transferred back to conventional gasoline gas stations.
At the same time, users are unwilling to accept methanol gasoline. Methanol vehicles have many faults and high maintenance costs. The most troublesome thing is that it is inconvenient to add methanol and gasoline. In Europe, 3% methanol is allowed in gasoline, but statistics show that less than 0.5% methanol is added in fuel [4].
3.2 The relative reduction of environmental advantages is also an important reason for the decline of methanol gasoline.
Environmental protection used to be an important factor to promote the development of methanol gasoline, but later it became an important reason to restrict its development.
First of all, in the early 1990s, the United States introduced new formula gasoline according to the Clean Air Act Amendment. First of all, this clean fuel regulation limits the content of chemical components in automobile gasoline to reduce emissions and improve air quality, which leads to the optimization of gasoline components and the development of global gasoline cleanliness. The application of new gasoline formula makes the environmental advantages of methanol relatively reduced. It is worth pointing out that methanol used MTBE (methyl tert-butyl ether) as the oxygen-containing component in the newly formulated gasoline, which significantly reduced the air pollution caused by automobile emissions. However, it was later found that MTBE has some problems such as high water solubility, poor biodegradability and rapid migration to drinking water, which is harmful to human health. Therefore, American legislation prohibits the addition of MTBE.
Secondly, although the use of methanol gasoline can reduce the emissions of CO and nitrogen oxides in the tail gas, the total formaldehyde emitted from the tail gas has increased by more than three times, and formaldehyde is a carcinogen. After adding methanol to gasoline, the vapor pressure increases obviously, and the volatilization loss increases during transportation, processing and use. In addition, methanol is quite toxic, so the use of methanol gasoline has obvious negative impact on the environment.
The International Energy Agency (IEA) commissioned the Finnish National Experimental Research Center to test the automobile exhaust emission performance of several clean fuels [5]. See table 1995 for the test and evaluation report; Sweden also did this test in the 1980s, and the results are shown in Table 2.
Finally, in the 1990s, the fact that the greenhouse effect caused the earth's surface temperature to rise was confirmed and attracted great attention. Heads of state agreed to take measures to reduce greenhouse gas emissions, which also became the driving force for the development of alcohol fuel. Ethanol fuel is made from biomass. Plants absorb CO2 in the atmosphere through photosynthesis during their growth, which can compensate CO2 emitted by burning ethanol fuel and help reduce CO2 emission to the atmosphere. However, methanol is mainly produced from mineral raw materials (coal and natural gas), which is a non-renewable fuel and cannot reduce CO2 emissions, which has a negative impact on the climate. Therefore, governments all over the world have turned to the development of bioethanol.
3.3 The policies of Europe, America and other countries determine that methanol gasoline is gradually replaced by ethanol gasoline.
2 1 century, due to the progress of petroleum production technology and automobile production technology, the emission performance of gasoline vehicles has been greatly improved, and from the perspective of environmental protection, the advantages of methanol fuel are relatively reduced; At the same time, due to the aggravation of oil shortage and people's concern about climate change, bioethanol has received more attention. The state governments of American agricultural states are willing to support the development of ethanol fuel in order to support their own agriculture. In addition, farmers have great influence on the policies of Congress, which makes ethanol fuel get more support. European and American governments gradually gave up their policy support for methanol fuel and supported the development of bioethanol.
In 2005, the "New Energy Act" launched an energy tax reduction plan of $654.38+0.8 billion to encourage the use of ethanol energy. It is predicted that by 20 12, the annual output of fuel ethanol or biofuel will reach 75× 108 gallon. At the same time, in order to prevent groundwater pollution, it is forbidden to add methyl tert-butyl ether (MTBE) to gasoline. In addition, the American unleaded gasoline standard ASTM 48 14 requires that the methanol content in gasoline should not exceed 0.3%.
In the United States, the number of M85 methanol vehicles in 1997 exceeded 2. 1× 104, and the highest annual consumption of M85 methanol fuel reached 245× 104 gallon gasoline equivalent. However, after 1998, methanol-fueled vehicles and methanol fuel in the United States are decreasing. At the same time, ethanol gasoline with low toxicity and good safety overcomes the above shortcomings of methanol gasoline, has been developed vigorously and its consumption has increased rapidly. By 2003, methanol fuel was almost completely replaced by ethanol fuel. See Table 3[6] for the car ownership and methanol and ethanol fuel consumption in the United States from 65438 to 0992 to 2007.
In Germany, Sweden and other European countries, the application of methanol gasoline was initially promoted by M 15, but after the end of 1980s, methanol gasoline was gradually abandoned. At present, the addition of methanol in European automobile gasoline is limited to 3% (volume fraction), which is only equivalent to adding oxygen-increasing agent to change the performance of gasoline. As early as 1993, Europe * * * has required that gasoline blended fuel contain 5% ethanol.
3.4 The temporary loss of economic competitiveness has also accelerated the decline of methanol gasoline.
At that time, European and American countries mainly used natural gas as raw material to produce methanol, and natural gas mainly relied on imports. After the two oil crises in the 1970s, oil was vigorously developed all over the world, oil production flourished and the relationship between supply and demand was comprehensively adjusted. In the mid-1980s and 1990s, the world oil price kept falling, from 1993- 1995 to 15-20 USD/barrel. At the same time, the prices of natural gas and methanol continue to rise, and the highest price of methanol has risen to more than 500 dollars/ton, which makes methanol fuel lose its economic advantage, leads to the loss of enthusiasm of countries to continue to develop methanol fuel, and accelerates the decline of methanol gasoline.
4 Enlightenment from the development of methanol gasoline abroad
In recent years, China's methanol production capacity has grown rapidly, with a serious overcapacity, and the existing consumption fields cannot digest the rapidly growing production capacity. In 2008, China's methanol production capacity reached about 2800× 104t/a, while the operating rate was only about 40%. On the other hand, with the sharp rise of international crude oil prices in recent years, the price difference between refined oil and methanol has been expanding. Therefore, the methanol industry and some local governments are keen to promote methanol gasoline, trying to promote methanol gasoline as an important way to expand the demand of methanol market. Some local governments have issued local standards for methanol gasoline and started pilot work. The methanol industry claims that the technical problems in the application of methanol gasoline have been completely solved, and constantly calls on the state to introduce clear policies and measures and formulate national standards. Some unscrupulous gas station dealers either explicitly or implicitly mix methanol into ordinary gasoline and sell it as ordinary gasoline, which harms consumers and makes use of the price difference between ordinary gasoline and methanol to obtain ill-gotten wealth. However, due to the careful consideration of environmental protection and safety, the state has never issued clear policies and measures for methanol fuel.
Through the investigation and analysis of the development process of methanol gasoline abroad from research and development to demonstration and promotion to recession, the author puts forward the following suggestions.
4. 1 China should ban the use of methanol gasoline.
Although the conventional emission of methanol is lower than that of ordinary gasoline and diesel, the current price (at the same calorific value) is lower than that of gasoline, and there is a serious overcapacity in China, the author still suggests that the country ban the use of methanol gasoline. The main basis is as follows:
First of all, methanol has obvious defects as automobile fuel. It mainly includes: ① methanol is toxic and easy to cause personal injury, which can lead to blindness or even death in severe cases; (2) Methanol is corrosive and difficult to detect in a short time. Generally, engine failure occurs after 5-6 years, shortening the service life of the car; The calorific value of methanol is only half that of gasoline, which limits the driving distance of vehicles; ④ It is difficult for methanol gasoline to start cold in winter, but it is easy to have "gas resistance" in summer; ⑤ When methanol gasoline is used, the unconventional emission of formaldehyde in automobile exhaust is much higher than that of ordinary gasoline, and formaldehyde is a strong carcinogen. Therefore, consumers in developed countries are reluctant to accept methanol gasoline.
Second, methanol cannot be compared with ethanol and MTBE. Ethanol and MTBE, as automobile fuels, have no obvious defects. The main problem of ethanol is that it is easy to separate phases when it meets water, which leads to corrosion problems, and methanol also exists and is more serious. The main problem of MTBE is that it may pollute groundwater, so the United States banned MTBE, but this problem has not been found in Europe and Asia, and MTBE is regarded as an important gasoline blending component. It can be seen that methanol has obvious disadvantages as automobile fuel and cannot be compared with ethanol and MTBE. Therefore, automobile companies and oil companies in developed countries do not support methanol gasoline.
Thirdly, the use of methanol gasoline runs counter to the promised goal of developing a low-carbon economy in the world and achieving a significant reduction in carbon dioxide emission intensity in China. At present, all countries in the world are developing low-carbon economy one after another, and China also promises that the carbon dioxide emissions per unit GDP will be reduced by 40%-45% compared with 2005. In order to develop a low-carbon economy and achieve the promised goal, we must adjust the energy structure, greatly reduce the proportion of coal with high carbon-heat ratio (the ratio of carbon dioxide emissions to fuel combustion calorific value), increase the proportion of natural gas with low carbon-heat ratio in primary energy, and vigorously develop renewable energy and nuclear energy with basically zero carbon-heat ratio. In China, methanol production is mainly based on coal, and the energy consumption in the production process is also high. No matter from the point of view of developing low-carbon economy or using energy efficiently, methanol is not suitable as automobile fuel. Therefore, the governments of developed countries finally have to give up methanol gasoline.
It is the reason why PetroChina has not pushed methanol gasoline.