Hydrogen powered cars use a fuel cell to generate energy. They combine hydrogen that is stored in a tank and oxygen that comes from the air to form water and electricity. The chemical energy that is stored in the hydrogen is converted to mechanical energy which powers the car . Combustion engines on the other hand use hydrocarbon fuels to propel the car. The piston is pushed downwards by rotation of the camshaft which makes the intake valves to open up and in turn fills the chamber with fuel and oxygen. At this time the exhaust valves remain closed. The intake valves close as the piston approaches its lowest position. Both valves remain closed as the piston compresses the fuel mixed with air. The spark plug causes the mixture to ignite. This combustion results in conversion of chemical energy stored in fuel to mechanical energy that is used to propel the vehicle .
In 2003, the then US president George Bush announced an initiative of US$1.2 billion investment to develop hydrogen powered cars. He envisioned that by the year 2020, there will be mass production of hydrogen powered cars . Unfortunately over the years the enthusiasm of research on these vehicles has reduced as attention shifted to bio fuels and batteries. Hydrogen powered cars are finally making a comeback. There several benefits that would accrue from using these vehicles as outlined in this paper.
Reduction in levels of CO2
Hydrogen gas that is used as fuel in hydrogen powered cars is obtained from various sources. One of the sources is electrolysis of water molecules to remove hydrogen. Water molecules are a compound of hydrogen and oxygen therefore electrolysis of water increases the level of oxygen in the atmosphere. Even when hydrogen gas is extracted from fossil fuel, natural gas or gasoline, it cuts emissions of nitrous oxides, sulphur oxides, carbon dioxide and other pollutants by 60% compared to their regular use in combustion engines
Hydrogen powered vehicles do not cause the environmental hazards associated with fossil fuels. They have negligible or zero emissions. Heat and water vapor are the only by-products. The combustion of hydrogen in a fuel cell is a flameless process and therefore the resulting emissions does not contain CO or CO2 .A study by the National Academies of Science and the NHA's Energy Evolution indicate that hydrogen powered cars can reduce emission of CO2 by 80% by the year 2050
Safety of hydrogen cars
Hydrogen gas is a lot safer than other sources of engine fuel such diesel, natural gas, gasoline and propane. Hydrogen gas is less harmful when it leaks. It is tasteless, odorless and it does not have negative health effects unless it is in very high concentration. It quickly oxidizes when it comes in conduct with air to form water which is harmless. Hydrogen gas has a low density; it therefore quickly disperses before it reaches combustible levels. In case combustion takes place, it is not explosive therefore a hydrogen tank that is damaged can leak its contents without causing any accidents .
Maintenance of hydrogen cars
The only movable parts in fuel cells are blowers and compressors that are involved in heat and water management. This means that they have less likelihood of wear and tear. They therefore require less maintenance as compared to combustion engines
Efficiency Compared to combustion engines, hydrogen is far more efficient. The energy density per unit mass of hydrogen is higher compared to gasoline, natural gas or diesel. At the same time, the energy density per unit volume of hydrogen is low. As a result, hydrogen cars need a small fuel in travelling greater distances as compared to gasoline cars. They can therefore travel for longer periods before refueling. Use of chicken feather fibers increase the surface area of hydrogen tank therefore it can hold more hydrogen gas .Experiments show that fuel cells can extract more energy from the same quantity of fuel than combustion engines. They can make vehicles 30%-90% more efficient compared to vehicles with combustion engines .
In the universe, hydrogen is the most abundant element. It is found in numerous compounds. It can be produced from hydrocarbon fuel that includes natural gas, fossil fuel and oil. It can be obtained from biomass in landfill waste, wastewater sludge, and livestock waste. It can also be obtained from algae or bacteria through their normal metabolism or water Noise
Hydrogen powered cars produce little noise. This is attributed to the fact that they have fewer moving part compared to combustion engines. They can therefore be instrumental in reducing the level of noise pollution.
With hydrogen cars, various consumers will be independent. Currently, there is overdependence on oil as a source of power for vehicles. The oil suppliers enjoy monopoly power and can dictate the oil prices as they wish. A shift to hydrogen cars will create independence as the sources of hydrogen are numerous. Consumers will also be cushioned from fluctuation of oil prices in the international market. The US Department of Energy postulates that the adoption of hydrogen powered vehicles will reduce import of oil by 800,000 barrel per day. This represents 13% of the USA import budget
In the wake of increased global warming there is concern of reducing emission of green house gases. Hydrogen powered cars will help create a pollution free environment. It will also reduce dependence on fossil fuels, increase efficiency of cars, reduce noise pollution and improve safety of cars.
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