Depleting fossil fuel reserves and increasing vehicular emission have forced the attention of various petroleum industries to find and alternate fuel that will power the vehicle in future based on the present day internal design as the deposits of crude oil is expected to last for another 50 years at the minimum utilization level .the proposed fuel should suitably replace the existing fuel and at the same time it should be renewable Hydrogen is one such fuel that has been proposed for the purpose which was suitable for spark ignition engines .hydrogen combines the properties of higher calorific value ,higher velocity of flame propagation ,non toxicity as well as lowest possible emission levels that do not affect the balance of the water of the hydrosphere.
More over the by product of combustion are devoid of carbon dioxide, carbon monoxide which is the major advantage of vehicles powered by fuel cell vehicles.
Fuel cell vehicles represent one of the emerging technologies of the innovation age. An efficient, combustion less, virtually pollution free, free power source capable of being sited down town urban areas or in remote regions, that runs almost silently, and has few moving parts but these vehicles are more reality than dreams. Fuel cells are one of the cleanest and most efficient technologies for generating electricity. In the quest of environment friendly energy generation researchers have come up with comparatively much safer fuels. It is truly a green technology. Fuel cell is the practical, feasible and marketable solution to the energy crisis. The technology is extremely intersecting to people in all walks of life because it offers a mean of making power more efficiently and without pollution.
World automakers seem to believe that low emissions, high efficiency fuel cell will eventually deliver the power and the performance that users expect. Despite difficult technical and market challenges to over come, the latest crop of fuel cell powered concept car appears to exhibit many basic feature required for the success of this concept.
Fuel cell or ZEV’S as they are called are vehicles to look up for as future vehicles. The topic on fuel cell vehicles deals with all the issues and signs related to fuel cell vehicles and their future that is sometimes questioned. However the answers to these questions have been successfully dealt with in the following sub-topics:
Hydrogen & fuel cell vehicles: Hydrogen is the most abundant element in the universe, but it currently is not be a practical transportation fuel by itself because of storage problems. Hydrogen is normally a gas at room temperature, and storage as a gas requires large containers. Storing it as a liquid requires super-cold temperatures. And because hydrogen is the simplest element, it can even "leak" through the strongest container walls.
One of the most widely suggested sources of electricity for a hybrid electric vehicle is a fuel cell powered by hydrogen. By chemically combining hydrogen and oxygen, rather than "burning a fuel," electricity is created. Water vapor is the by-product.
The fuel cell power system involves three basic steps. First, methanol, natural gas, gasoline or another fuel containing hydrogen is broken down into its component parts to produce hydrogen. This hydrogen is then electrochemically used by the fuel cell. Fuel cells operate somewhat like a battery. Hydrogen and air are fed to the anode and cathode, respectively, of each cell. These cells are stacked to make up the fuel cell stack. As the hydrogen diffuses through the anode, electrons are stripped off, creating direct current electricity. This electricity can be used directly in a DC electric motor, or it can be converted to alternating current.
To carry gaseous hydrogen on a vehicle, it must be compressed. When compressed (usually to a pressure of about 3000 pounds per square inch). Hydrogen is stored under great pressure, 3600 and 5000 PSI in the big tanks, 7000 PSI in the smaller distribution tanks.
The other way to provide hydrogen gas to the fuel cell is to store it on the vehicle in liquid form. To make hydrogen liquid, it is chilled and compressed. Liquid hydrogen is very, very cold--more than 423.2 degrees Fairenheit below zero! This super-cold liquid hydrogen is the kind used in space rockets. The containers are able to hold pressure, but they are also insulated to keep the liquid hydrogen from warming up. Warming the liquid, or lowering the pressure, releases gas (like boiling water), and the gas can go to the fuel cell.
Another way to get hydrogen to the fuel cell is to use a "reformer". A reformer is a device that removes the hydrogen from hydrocarbon fuels, like methanol or gasoline. . A reformer turns hydrocarbon or alcohol fuels into hydrogen, which is then fed to the fuel cell. Unfortunately, reformers are not perfect. They generate heat and produce other gases besides hydrogen. They use various devices to try to clean up the hydrogen, but even so, the hydrogen that comes out of them is not pure, and this lowers the efficiency of the fuel cell
When a fuel other than hydrogen is used, the fuel cell is no longer zero-emission
Use of battery unit:- Small test batteries made under the technology department are stored in one unit to form a single module model of ten batteries.This unit is then used to power the vehicle through the power train and motor as well as the controller which are installed accordingly and this method proves useful in special cases where the fuel cell stack is not work properly due to technical difficulties