As the worldwide demand for affordable electricity continues to rise, so does the demand for sources of energy that will not foul the air or water. Nuclear energy was once considered the best option to supply both of these demands, but nuclear energy plants produce radioactive waste that will remain hazardous for tens of thousands of years. Existing radioactive waste may be stored properly, but many people have concerns about it eventually eroding containers and contaminating the environment. As a result, very few nuclear energy plants have been built in the last several decades.
Different Fuel, Different Plan
Power plants that use coal as a fuel continue to be built, but most are outside of the United States in developing countries. Some of these plants are not near a source of coal, so the coal must be shipped, expending extra energy in the process. Coal is quickly becoming unpopular in Europe and North America, which may drive down the price of coal in developing nations. Some electrical generation facilities have used fuel oil, but this is also considered a dirty fuel. The cost of using oil also has a tendency to eliminate profit margins for producers of electricity.
Design for the Future of Energy?
To adapt to these conditions, those who plan construction of new power plants are often designing them to use natural gas as a source of fuel. Natural gas burns cleanly, so it makes compliance with emissions standards very simple. Natural gas does produce some pollutants, such as nitrogen oxides and carbon dioxide, but much less than burning coal. Power producers must remove mercury from the exhaust produced by burning coal. Mercury is considered quite toxic and can be expensive to scrub out of emissions. Much natural gas is now produced as a byproduct of hydraulic fracturing (known as fracking) when drilling for oil. Fracking has been blamed for groundwater contamination, so using natural gas as a fuel for generating electricity is not completely without environmental stigma. It is still considered cleaner than coal, oil or nuclear energy.
Cleaner, Greener Energy?
One advantage of designing power plants that use natural gas is that the fuel itself requires much less processing before it can be used. Coal must be broken down into very small fragments before it can be burned. This means added costs, as well as expenditure of energy to produce energy. The net return of energy when using natural gas is higher than when using coal. Making natural gas ready for use as a fuel involves removing impurities and moisture. Natural gas can be piped into a power plant rather than delivered by train and then processed. Of course, natural gas is much more flammable than coal, so great care must be taken in the design and execution of delivery of natural gas to an electric plant. Plants that use natural gas have more flexibility in how electricity is generated. The fuel can be used to produce steam to drive turbines as coal-fired plants do. Natural gas can also be used as a fuel in internal combustion generators. When internal combustion generators are used, the heat emitted by the generators can be used to heat water for steam. This results in a higher energy return on the energy input.
This article was written by Mario Wentworth, an aspiring engineer who hopes to help you understand construction and engineering better. He recommends keeping track of the latest developments in gas processing plants as well to see how construction is constantly improving.