Experts believe that the metal powder will become a future fuel for the power plant automobile engines. Dave Beech, a researcher at Oak Ridge National Laboratory in Tennessee, is conducting research in this area. He believes that iron , aluminum and boron can be made into fuel materials. The processing of these ordinary substances into very fine nano-sized particles will become very active and ignite them, releasing huge amounts of energy. Beechcraft estimates that the engine will be modified to use a full-box fuel cell made of metal powder, and an ordinary car can travel three times the distance of a gasoline-powered car. More preferably, since the nano metal fuel is burned differently than the general fossil fuel, it is almost non-polluting. That is to say, there is no carbon dioxide, no dust, no smoke, no nitrogen oxides. In addition, the metal fuel cell is fully rechargeable: just add a little hydrogen to the used nanoparticles and the battery can be burned again and again. This new fuel cell can be used not only for automotive engines, but also for turbines of other engines or power stations. First, release the metal oxide layer The rocket is already using metal powder as a fuel. For example, adding a small amount of aluminum adds extra power to the spacecraft's solid rockets. In addition, metal powder fuel is also used in rocket-assisted torpedoes. However, the use of metal powder fuel in rocket engines is quite different from the use of metal powder fuel in automotive engines. When metal powders such as iron or aluminum are in contact with air, an oxide layer is formed on the surface. In order to ignite the metal, the metal oxide must be removed first. If most of the metal is to be burned, at least a heat source of 2000 ° C is required, which can evaporate the metal oxide layer and expose the active metal inside. This principle applies to rockets, but for car engines, there is a problem. Once the evaporated metal oxide begins to cool, it condenses into a solid and forms ash. For rockets, high temperatures and ash are not a problem, but for any type of internal combustion engine intended to burn metal powder, this can be a big problem. Solomon Rabinov is also a researcher at Oak Ridge National Laboratory. As early as the early 1980s, he served as director of an engineering research institute in Kiev, Ukraine, when his research team tried to make the internal combustion engine use micron-sized iron powder as fuel. They rebuilt an engine so that it could start at high temperatures. It was found that the ash formed by the oxide deposited on the piston, the cylinder wall and the valve, blocking the engine. Because they could not find a way to solve this problem, they had to give up the research. Rabinov later moved to the United States to work at Oak Ridge National Laboratory. In 2003, he suggested that Dave Beach and the theorist Bobby Sumpt re-examine the issue. This time they used nano-sized iron powder. In the experiment they found that 50 nanometers of iron powder is easier to ignite than the larger iron powder that Rabinov used before: heating them to 250 ° C, even if there is only one spark, they can be ignited. Nanoparticles are easy to burn because of their large surface area to volume ratio. Iron reacts easily with oxygen. If many iron particles are exposed to the air at the same time, oxidation produces enough heat to spontaneously ignite the iron. In order to avoid this, in the process of producing nanoparticles, it is usually covered with a protective oxide film. But even with such an oxide layer, the large surface area of ​​the nanoparticles means that as long as there is little heat, it is easy for oxygen molecules to pass through the oxide layer and ignite the metal. Thus, once the nanoparticles are ignited by the spark, they burn extremely quickly, at temperatures up to 800 ° C, which is enough to do useful work, but does not melt the engine made of alloy. More critically, unlike micron-sized particles, the nanoparticles do not burn so hot that they evaporate or melt, they just oxidize and then produce a pile of nanoparticulate oxides. This means they won't stick to the cylinder wall and will not block the engine. Second, control the heat production rate of nanoparticles Observing the neat iron oxide ash left behind after burning, Beechcraft came up with the idea that turning iron oxide into a usable fuel can be quite easy. He heats the burned fuel with a hydrogen stream at a temperature of 425 ° C, and as a result, iron oxide particles are reduced to iron. Hydrogen combines with oxygen to form water. As a result, the nano fuel can be burned again. However, in order for this nanoparticle to be a truly practical fuel, one problem needs to be solved: the nanoparticle will burn in an instant, and the heat will evaporate in about 1 millisecond. In order to widely use this kind of metal fuel on various engines, the heat production rate should not be so fast, because the engine cannot cope with the heat generation of the fuel. In an internal combustion engine, the burst of each combustion lasts for 5 to 20 milliseconds. If the rate of heat release is too fast, the efficiency of fuel combustion is not high. As a result, researchers have used methods to process tiny nanoparticles into larger particles to limit their rate of combustion. The idea is to limit the rate at which oxygen diffuses to the nanoparticles and to limit the rate at which heat fluctuates toward the nanoparticles. This will reduce the rate of heat release. The study was successful. Beech and colleagues made individual nanoparticle clusters weighing between 1 and 200 mg. By adjusting the size, shape and density of these nanoparticle clusters, they can control the rate of metal burning. While individual nanoparticles will burn in milliseconds, larger clusters of nanoparticles can burn in 500 milliseconds to 2 seconds. Third, transform the ordinary diesel engine Currently, as the first phase of research has been completed, the research team is designing an engine that can operate with this fuel. To convert an externally-burning engine, such as a gas turbine that powers a vehicle such as a jet or a tank, and an engine that generates electricity from a power station into an engine that can use metal fuel, it is necessary to modify the fuel delivery system, but Beech believes that this transformation It won't be difficult. He felt that it was imperative to find a way to collect waste fuel. Nano metal fuels can also power the Stirling engine. A Stirling engine is a high efficiency external combustion engine that utilizes alternating cooling or heating of liquid or gas in a cylinder to move the piston. The Stirling engine may also be used in cars. NASA and automakers, including Ford Motor Company, have designed power cars for trials of Stirling engines. However, Beech also hopes to use metal fuels on internal combustion engines. A modified ordinary diesel engine may use this nano metal powder as a fuel. Beech proposes that an air jet can be used to provide both the oxygen required for combustion and the injection of nano metal powder or powder clusters from the storage tank into the engine. The spark plug triggers ignition and burns the nanofuel in the cylinder. Regarding the collection of spent fuel, Beech's research team believes that a method can be used to divide the fuel tank into two parts with a movable membrane, one with unused fuel and the other with used fuel. Since the powder of iron oxide is magnetic, it can be sucked by an electromagnet, so the used fuel can be collected by a filter. When the driver needs to "fuel" the car, he can go to the feeding station to replace the entire fuel tank with a tank filled with fresh nano fuel, and the used nano fuel tank can be reused after the hydrogen supply of the fuel supply station. Fourth, the advantages and disadvantages of using metal powder fuel The engine uses metal powder fuel that does not emit carbon dioxide and emits no harmful particulate dust or nitrogen oxides. These compounds are usually formed by combustion under high temperature conditions. Beech has shown that the temperature can be lowered to 525 ° C by changing the size of the cluster of nanoparticles. Experts believe that with metal powder as fuel, there is still a lot of work waiting for further research, such as the temperature of combustion, the balance between speed and the efficiency of the engine. The use of metal powder as a fuel for automobiles is beneficial to both the driver and the environment. According to Beechcraft, a fuel tank can carry 33 liters of metal fuel, which provides the engine with the equivalent of 50 liters of regular gasoline or diesel. However, experts point out that metal fuels also have their own shortcomings. According to Nathan Glasgow, an adviser to the Rocky Mountain Institute in Colorado, the most important thing is the weight problem, because the proportion of metals such as iron is large. Although the metal fuel in a 50-liter fuel tank has much higher thermal energy than the same volume of gasoline or diesel, such a tank of fuel weighs 100 kilograms and weighs twice as much as gasoline. In addition, because the burned metal oxide is always stored in the car, it also increases the cost of processing. David Keith, a physicist at the University of Calgary in Canada, believes that this technique sounds effective, but there are some basic difficulties in actually using metal as a fuel. If you don't say anything else, it's just too bad to be too heavy. Therefore, to say that the ultimate clean, green driving fuel, perhaps non-hydrogen. After all, the energy provided per gram of hydrogen is more than 12 times that of iron. However, Beech does not think so. He believes that metal is a more convenient, safer and more portable fuel than hydrogen. Indeed, for a long time, experts have been trying to find ways to store hydrogen of sufficient density to make it a practical fuel to replace gasoline, but so far no progress has been made. Metal fuels are easy to store and transport because they are fairly stable at room temperature. Beech said: "We get solid metal fuel under normal environmental pressure, then it will not be a problem if it is placed on a transport vehicle or stored for a long time." The use of hydrogen as a fuel for automobiles may also face a more serious problem. Water produced by the combustion of hydrogen fuel cells is usually released directly into the atmosphere. Some climatologists are concerned that if millions of hydrogen-powered cars release large amounts of water vapor into the atmosphere, they will accelerate global warming. The recovery of oxides from the combustion of metal fuels using hydrogen also produces water vapor. However, these water vapors can be collected and not discharged directly on the road like a car fueled with hydrogen. It can even be converted to hydrogen by electrolysis to be recycled. Beech pointed out that the use of aluminum nanoparticles as fuel, the capacity per kilogram is four times that of iron; and the use of boron as fuel is six times that of iron. Of course, because aluminum and boron are expensive, the cost of such fuels is much higher than that of iron. For example, the cost of aluminum nanofuels is 15 times higher than that of iron fuels. 5. Metal powder will become the fuel of the future The early stages of metal fuels are still being studied. Researchers at Oak Ridge Labs are applying for approval to develop prototype engines. The Beech team is conducting a comprehensive analysis to see if metal fuels are cost effective. They also plan to conduct a series of experiments to optimize metal particle size and explore the best way to package, inject and collect these fuels in real engines. However, even if their research is finally successful, they face some questions: Who will buy the first metal-powered car that doesn't know where to go? Who would dare to take the lead in investing in this metal fuel supply station before this car is yet to become popular? However, experts point out that engines using metal fuels are one of the new attempts to replace fuel engines. And regardless of the future results, Beech's current compelling vision is feasible. In the past, energy giant won hundreds of millions of wealth from coal, oil and natural gas fields. In the future, they may make a big fuss in the field of metal fuels, using waste metal materials to make a fortune. Flexible Chain Conveyor Flexible Chain Conveyor Vitrans Automation Equipment Co.,Ltd , https://www.vitrans-automatic.com
Metal powder: future fuel