2012年4月7日星期六

Alternative Fuels

Although fuels such as gasoline and diesel are the most popular energy source for cars, there are several others, especially less polluting ...
Alternative fuels are patterns of energy use something other than oil, including gasoline and diesel. They have the great advantage of reducing pollution and emissions of greenhouse gases. There are several types including electricity, ethanol, natural gas, liquid propane, fuel cells and hydrogen, batteries for electric and hybrid vehicles, biofuels, clean diesel, etc..
Electric vehicles
First, there is this type of vehicle that is becoming increasingly popular. It uses only one power, that of electricity. The electric vehicle thus produces no pollution and people with a do not need to visit petrol stations.
Although electric vehicles make a lot of attention for a short time, it's not yesterday that it exists. The electric motor appeared simultaneously with the car, which means the 19th century, as the combustion engine and steam. But it is especially in recent years that there is a resurgence in the field by some companies, including Mitsubishi, GM, Renault-Nissan and the company Bolloré. Since then, every automaker tries to have its fleet in its own electric model.
These are complex technologies, but in a few words, so that energy can move the vehicle, energy is created and stored in batteries and it is one or more electric motors that is the basis of operation. Battery charging is done via a external power source, a conventional electrical outlet in the house, but there are also more powerful kinds of chargers to reduce the cooldown.
19th century until today ...
However, whether the 19th century or today, the problems remain the same. They translate, how to increase the driving range and how to set up a network of supply for charging interest? If these problems persist since the 19th century and it is still difficult to find interesting and possible solutions, why continue to put as much effort on these systems? The fight against pollution and greenhouse gas emissions is becoming more and more people, as well as any possibility that there is more oil a day and the price of gasoline continues to climb ensure that electric cars are becoming increasingly attractive.
Research continues therefore to improve the autonomy, the life, efficiency and time to recharge the batteries. However, models built today are more powerful than before and also better designed, giving a chance to batteries offer higher yields.
Example Vehicle: Mitsubishi i-MiEV, Tesla Roadster, Nissan Leaf
Ethanol
This product consists of a mixture of ethanol and gasoline. This energy source could reduce emissions of toxic air about 4 10%. Most cars can use ethanol without the systems, including the engine, be modified, however, must not exceed an amount greater than 10% in the blend with gasoline. Ethanol and equipped with the EcoLogo certification "Environmental Choice" must have been made from corn, wheat or wood, or renewable natural resources.
Biodiesel
This product is considered as an alternative fuel for diesel. It is made from vegetable oil or waste cooking or animal fats. Biodiesel is considered to be less harmful to the environment because it burns better, so it produces fewer toxic emissions.
Natural gas
Like biodiesel, natural gas burns better, therefore produces fewer toxic emissions into the air. It is also more efficient than gasoline and traditional diesel. VGN called for natural gas vehicle, this compound has proven and continues to do them. Moreover, there are over 25,000 such vehicles in Canada. It is also possible to convert a gasoline vehicle into NGV. However, this is still the way to recharge problematic in this type of alternative fuel.
Liquid propane
Propane is a byproduct of natural gas and oil refining. This is actually a product gas under pressure, but stored in liquid form. Similarly we recharge his vehicle with gasoline, propane refueling is fast and is calculated by the liter.
Like the vehicles running on natural gas, it is also possible to convert a gasoline vehicle to vehicle propane. According to available data, propane could reduce emissions of greenhouse gases up to 20%. It is mainly large consumers of gas who use this type of fuel, such as delivery vehicles.
Fuel cell vehicles
A fuel cell is a current generator that transforms chemical energy into electricity through the oxidation of a fuel, for example of hydrogen and oxygen in the air, which occurs on the electrodes. The kind of battery is the most commonly used battery dihydrogen-dioxygen.
For some time, with research and studies, the fuel cell has become a very attractive alternative fuel. In addition to not produce any pollutants, they also have the advantage of having an energy-efficient.
The rechargeable batteries have both electrodes (anode and cathode) separated by an electrolyte (instead of the chemical reaction). The main difference between the various cells is the electrolyte, the product (gas or liquid) of the anode and the cathode gas.
There are many types of fuel cells including:
◦ fuel cell formic acid◦ fuel cell phosphoric acid◦ alkaline fuel cell◦ cell molten carbonate fuel◦ ceramic fuel cell protonante◦ ethanol fuel cell direct◦ fuel cell borohydride direct◦ reversible fuel cell◦ cell direct methanol fuel◦ photoelectrochemical cellThere are also other types of batteries, the best known are the cell solid oxide fuel, which is expensive but offer superior performance and fuel cell proton exchange membrane, which is the most interesting and promising for the automotive industry with a low operating temperature, its simplicity and good performance. This type of battery, although it has many qualities, however, an overall performance that is not high enough for use in mass. Studies are currently underway to improve the whole.
Fuel cells to hydrogen and methanol production methods are derived from the fuel cell.
Hydrogen fuel cells
This type of battery converts chemical energy into electrical energy, but directly and thus get a continuous stream. In this case, hydrogen fed to the anode and oxygen cathode. Its voltage is 1.2 V and can radiate heat up to 60 to 80 ° C.
What is nice with hydrogen fuel cells is that because they are based on hydrogen, they are not harmful to the environment. Some say it could also become the main energy resources in Canada for green transportation. Called VPC, for fuel cell vehicles, it is a method similar to battery electric vehicles. The major difference lies in the manufacturing process where instead of creating electricity by a reversible electrochemical reaction, electricity is generated here through an irreversible electrochemical reaction of oxygen and hydrogen.
Methanol fuel cell
There are two types of fuel cells based on methanol. First, there are the batteries Reformed Methanol Fuel Cell (RMFC) and also the batteries Direct Methanol Fuel Cell (DMFC). The difference is at the conversion of methanol. This type of battery is not very healthy for the environment, unlike hydrogen fuel cells, because they reject a lot of carbon monoxide and CO2.
There are also many other types of fuel including gasoline and clean diesel, liquefied petroleum gas, and dual fuel vehicles to flexible fuel, batteries (nickel metal hydride battery (NiMH), lithium-ion battery), the lead-acid batteries and hybrid electric vehicles already covered in another folder.
Automakers that offer vehicles or who have developed a prototype using the fuel cell are numerous. There is for example, Ford, GM, Honda, Hyundai, Toyota, Renault-Nissan, etc..

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