Hydrogen-Oxygen Fuel Cell Technology
Is Hydrogen-Oxygen Fuel Cell Technology a practical alternative to carbon-based fuels in cars?
In recent years, a certain “advancement in technology” in the automotive scene has become an increasing common interest, as “the” resolution to environmental blight of the carbon-based fuel vehicles. This “advancement” has the potential to reduce the afflictions caused to the environment by the automotive industry. This “advancement” refers to the hydrogen-oxygen fuel cell vehicle or in short, fuel cell vehicles (Giulio Volpi, 2001) However, is hydrogen-oxygen fuel cell technology a practical alternative to carbon-based fuels in cars?
Chemical Concepts of Fuel Cell Technology
A fuel cell operates similarly like a battery, in which chemical energy is directly converted into electrical energy. However. The main difference between a battery and a fuel cell is the storage of fuel. In a battery, fuel is stored in the battery itself and the battery has to be recharged if the fuel no longer reacts while in a fuel cell, fuel is stored in separate compartments and delivered to the fuel cell when required.
As from the name itself, we can identify the primary composition of the fuel cell technology, which is hydrogen and oxygen. In a fuel cell, hydrogen introduced at the anode splits into positive hydrogen ions and free electrons. The positive ions move to the cathode via electrolyte where oxygen is introduced. Oxygen binds with hydrogen ions at the cathode to form water. Free electrons released at anode will move from anode to cathode in order to complete the process and this flow of electrons creates a current that powers the electric engine(Giulio volpi, 2001)
Benefits of Fuel Cell Technology
Fuel cells: A Solution to Climate Change? Giulio Volpi
Fuel cell vehicles have very low greenhouse gases(GHG), 60% fewer than a gasoline vehicle and 35% fewer than natural gas vehicle. The only by-products from fuel cells are water, heat and electricity. This means that unlike carbon-based fuel vehicles, fuel cell vehicles are environmental friendly and do not contribute to any greenhouse gases(GHG) emission(Forsythia Igot, 2002).
Fuel cells operate on hydrogen alone or any form of hydrogen. Hydrogen being the third most abundant element in earth, can be extracted from hydrogen containing sources by using either electricity or heat. Hydrogen can be produced from natural gas, coal as well as the splitting of water atoms(Kuznetsov V.L., David W.I.F, and Brandon N.P, 2008). Hydrogen can also be extracted from enzymes(Forsythia Igot, 2002). Such a variety of sources makes hydrogen gas a secure fuel supply.
Fuel cells in comparison with internal combustion engines have a lower operating temperature and pressure, at 80-1000 degrees Celsius. Hydrogen fuel stations also have the potential to be stationed everywhere as the stations operate with minimal noise, and emissions unlike gasoline stations which require specific locations.
Simple in design, hydrogen fuel cells do not require any moving parts like an internal combustion engine. Thus eliminating mechanical systems of wiring and valves required for steering the vehicle. Furthermore, there is no need for an engine compartment as the fuel cell itself will be located at the wheels. Without these compartments, motor oil, brake fluids as well as transmission fluid is not needed
(Forsythia Igot, 2002).
Unlike internal combustion engines, fuel cells perform at higher efficiency and this makes fuel cells ideal in terms of efficiency. Fuel cells are 30%-90% more efficient than gasoline as more power is extracted out of the same quantity of fuel when in comparison with gasoline. This makes fuel cells the number one in various applications from small scale to large scale power generation ( P.P Edwards, V.L Kuznetsov, W,I.F David, N.P Brandon, 2008 and Forsythia Igot, 2002).
Safety of Fuel Cell Vehicles
Although there has been myths about hydrogen being an “explosive gas”, it is all but dispelled by NASA safety expert , Addison Bain. Fuel cell vehicles will carry 0.8GJ and 0.2GJ of hydrogen energy for a four passenger and two passenger car respectively and these hydrogen tanks are built to withstand the force of a 50mph head-on collision. Furthermore, fuel tanks on the vehicles are manufactured such that gunfire will not result in an explosion. Instead, hydrogen gas would merely leak out of the tank. Hydrogen gas also has a lower density compared to hydrocarbon fuel and is denser than air and float up into the atmosphere. Furthermore, hydrogen gas although may ignite when in contact with air, it will not explode unlike gasoline vapours (Forsythia Igot, 2002).
Disadvantages of fuel cell
Storage of hydrogen
Storage of hydrogen is a major obstacle as storing hydrogen in larger amounts are a hassle. Hydrogen must be compressed to approximately 3000lbs per square inch in order to store in vehicles. Another form of storage for hydrogen would be in a liquid state. However, this process requires high pressure and low temperatures which are proved to be hard at containing(Forsythia Igot, 2002).
Cost of fuel cell technology
Currently, fuel cell technology is an expensive technology. Fuel cell vehicles are manufactured using generally expensive as materials such as platinum which are used as catalyst in fuel cells(Giulio Volpi, 2001). A conventional car engine would cost approximately $3000 to manufacture, while the reformer alone of a hydrogen fuel cell would cost up to $5000. Furthermore, hydrogen-refuelling stations are costly to built in order to deliver hydrogen to vehicles. A medium-sized gas station would require about $47,000 to $70,000 to modify into a hydrogen-refuelling station(Forsythia Igot, 2002).