The application of methanol as an alternative fuel

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The combustion characteristics of methanol have two key features: first, it provides excellent cooling effects, which help to reduce the engine temperature and prevent overheating； Second is its extremely high resistance to detonation; it can burn at pressures higher than those permitted for high-quality gasoline without experiencing detonation. This is ideal for engines with high compression ratios and high performance. Fully leverage its high octane rating to deliver greater power. 　　The advantages of methanol are complete combustion and low volatility, resulting in fewer harmful gases such as hydrocarbons, nitrogen oxides, and carbon monoxide being emitted. The use of methanol fuel in gasoline engines also went through a rather difficult process, evolving from low blending ratios (M15, with methanol accounting for 15%) to high blending ratios in the late 1980s (M85–M100). 1. Methanol fuel cells: Direct methanol fuel cells are a variant of proton exchange membrane fuel cells; they use methanol directly without the need for prior reformation. Methanol is converted into carbon dioxide, protons, and electrons at the anode. As in a standard proton exchange membrane fuel cell, protons pass through the proton exchange membrane to react with oxygen at the cathode, while electrons travel through the external circuit to the cathode where they do work. Under alkaline conditions, the overall reaction is: 2CH4O + 3O2 = 2CO2 + 4H2O. At the positive electrode: 3O2 + 12e– + 6H2O → 12OH–. At the negative electrode: 2CH4O – 12e– + 12OH– → 2CO2 + 10H2O. Under acidic conditions, the overall reaction remains the same. At the positive electrode: 3O2 + 12e– + 12H+ → 6H2O. At the negative electrode: 2CH4O – 12e– + 2H2O → 12H+ + 2CO2. The desired operating temperature for this type of battery is below 120°C, which is slightly higher than that of standard proton exchange membrane fuel cells; its efficiency is around 40%. Direct methanol fuel cells are a variant of proton exchange membrane fuel cells; they use methanol directly without the need for prior reformation. Methanol is converted into carbon dioxide and hydrogen at the anode, just like in standard proton exchange membrane fuel cells, after which hydrogen reacts with oxygen. The desired operating temperature for this type of battery is 120°C, which is slightly higher than that of standard proton exchange membrane fuel cells; its efficiency is around 40%. Its disadvantage is that it requires more platinum catalyst than conventional proton exchange membrane fuel cells when converting methanol into hydrogen and carbon dioxide at low temperatures. However, this increased cost is offset by the convenience of using liquid fuel and the ability to operate without the need for reforming. The technology used in direct methanol fuel cells is still in its early stages of development, but it has successfully demonstrated that it can be used as a power source for mobile phones and laptops, and it holds potential for use by specific end-users in the future. 2. Methanol fuel controller: The “automobile gasoline-methanol dual-fuel electronic injection system” developed by Alchol Research possesses independent intellectual property rights. It stores methanol and gasoline in separate tanks, and an additional separate methanol electronic injection system is installed on the engine. Thereafter, the vehicle’s fuel system operates through the interaction of these two injection systems, ensuring that the engine meets its minimum requirements for gasoline, with the remainder being supplied by methanol. While maintaining the vehicle’s excellent starting performance and normal operation, this system increases the amount of methanol used to 100%; it is also able to adjust the optimal amount of methanol required by the engine, thereby identifying the best combination point and method between the two. At the same time, the mixing ratio of methanol and gasoline is adjusted according to the vehicle’s different driving speeds. 3. Methanol gasoline refers to M-series blended fuels in which methanol is added to gasoline and mixed using methanol as a fuel solvent. Among them: M15 (gasoline with 15% methanol added) refers to clean methanol gasoline, which is used as a vehicle fuel. It can be applied in various gasoline engines; it can replace conventional gasoline without altering the structure of existing engines, and it can also be mixed with conventional gasoline. Methanol blended fuel boasts good thermal efficiency, power performance, startability, and cost-effectiveness, and it offers advantages such as reduced emissions, lower oil consumption, as well as safety and convenience. Countries around the world have developed methanol gasoline with various blending ratios, such as M3, M5, M15, M20, M50, N85, and M100, based on their specific national conditions. Currently, commercial methanol mainly consists of M85 (85% methanol + 15% gasoline) and M100; M100 has superior performance to M85 and offers greater environmental benefits. 4. Methanol fuel vehicles: China’s first methanol vehicle was put into service in Datong, Shanxi Province, in 1997. To date, over 80 such vehicles are being used as intercity buses in Yangquan, as well as in Shouyang and Xiyang along the route from Taiyuan to Jinzhong. However, more and more people abroad are opposing the use of methanol as a vehicle fuel, mainly because methanol is highly corrosive, which undermines the durability of vehicles (160,000 kilometers). Furthermore, since methanol is toxic, improper use can easily cause harm to the human body or even lead to death. After 1998, both methanol fuel vehicles and methanol fuel in the United States declined, and currently there is only one methanol vehicle gas station left in California. All automobile manufacturers have stopped producing methanol vehicles; Ford ceased production of its M85 methanol vehicle in 1998. Technically, issues such as cold start problems, thermal resistance, swelling, corrosion, excessive formaldehyde emissions due to abnormal conditions, and stratification in methanol-fueled vehicles have been resolved. Moreover, problems related to commercial operations such as transportation and refueling have also been standardized. Disadvantages of burning methanol instead of other fuels: (1) It has a certain degree of corrosiveness. Although the corrosion inhibitors developed today can partially control corrosion, they only work for a short period of time and cannot meet the basic driving requirements of 80,000 to 160,000 kilometers for cars. (2) Methanol has a swelling effect on the rubber components of vehicles. Rubber components in cars serve to seal and connect things together; once they swell, it can easily lead to leaks, and may even cause accidents. Furthermore, regarding exhaust emissions, although gasoline vehicles release large amounts of pollutants, methanol-fueled vehicles emit substances such as formaldehyde, which also pollute the environment. (3) Methanol has lower energy, and its fuel consumption for traveling the same distance is almost twice that of gasoline; therefore, a larger fuel tank is required. (4) Methanol is a colorless, volatile liquid with high toxicity. It can accumulate in the human body and has **effects**. Ingesting 5–10 milliliters can cause blindness in both eyes, while consuming a large amount can lead to death. (5) Methanol is flammable, and its vapors can form explosive mixtures with air. (6) Methanol wastewater refers to the distillation residues discharged from the bottom of distillation towers during methanol production or utilization; its COD concentration can reach tens of thousands or even hundreds of thousands of mg/L, and it mainly contains methanol, ethanol, higher alcohols, and aldehydes ； It also contains some long-chain compounds. Discharging high-concentration methanol wastewater directly not only wastes a large amount of valuable resources but also causes severe environmental pollution; therefore, it should be treated comprehensively.