Fossil fuels are created when heat and pressure from the earth’s crust compress the pre-existing methane and oxygen. Over time the heat and pressure creates the fossil fuels we know today- coal, oil, and gas. Combustion is the process of fossil fuels being burnt to generate energy.
Causes why we burn fossil fuels Combustion of fossil fuels is widely used to create energy as it is very efficient. When burned, huge amounts of energy are generated using a relatively small amount of the fossil fuel. Renewable energy is currently unable to rival the efficiency of fossil fuel combustion. Fossil fuels are currently widely available and cheap to extract contrasting with renewable energy sources which are currently not as cost effective.
In most places in the world, wherever large amounts of fossil fuels are prevalent, a fossil fuel plant can be facilitated which is able to generate huge amounts of energy from a single location.Effects of burning fossil fuels Combustion of fossil fuels has a large negative impact on the environment. The carbon dioxide emission can cause the ‘greenhouse effect’. The greenhouse effect is the process when these by-products are released and get trapped in the earth’s atmosphere and unable to escape. The trapped heat remains inside the earth’s atmosphere, in turn causing the temperature of the earth to rise. This effects the environment for instance potentially fundamentally altering the distribution of water and ice across the planet causing abnormal weather conditions, higher water levels, and melting ice caps. The combustion of fossil fuels releases not only carbon dioxide, but also sulphur dioxide which is dissolved in the water.
Sulphur dioxide becomes trapped in the H2O in the atmosphere and when precipitation takes place can fall to the ground as rain water. This creates ‘acid rain’. These substances are toxic to trees and plants as the rainwater falls to the soil. Possible solutionsA possible solution is to capture the gas by-products created as they are burned at the power plant. The basic ways of this technology are post-combustion and pre-combustion carbon capture.
With post-combustion carbon capture, carbon dioxide is trapped after the combustion of fossil fuels, pre combustion means it is captured before it burns.When burning natural gases, filtering can be used pre combustion. By filtering the gas using a solvent that absorbs carbon dioxide, carbon dioxide is separated from the flue gases- water vapour, sulphur dioxides and nitrogen oxide. The solvent can be heated later, which will release water vapour and leave concentrated carbon dioxide. The carbon dioxide can be stored underground.
After this process, only 10% of carbon dioxide releases to the atmosphere. Filtering can be used post combustion. The combusted fossil fuel is cooled down and pumped into the absorber. Inside the absorber, a solvent is used to extract the CO2 from the gas.
Figure 1 – It shows simple diagram of the steps of pre combustion carbon capture.With pre-combustion carbon capture, carbon dioxide is captured before the fuel is burned. The fossil fuel is heated in pure oxygen to create carbon monoxide and hydrogen. This mix falls to the bottom of a flask.
By passing through a catalytic converter with steam, the gases in the flask will naturally begin to rise, and a chemical called amine will be put into the top. The amine will bind with the carbon dioxide and subsequently fall to the bottom of the flask, separating with the hydrogen that rises up out of the flask. After that, through a heating process, the carbon dioxide rises to the top and the amine drops to the bottom of the flask. The Environmental Protection Agency has instituted recent a standard, ‘The Clean Power Plan’, that will diminish carbon emissions from fossil fuel – fired power plants. This will include actions such as investing in renewable energy and implementing these facilities to subsidise from coal-fired power systems. The EPA can establish temporary and final carbon dioxide emission performance rates to restrain the massive carbon emission from combustion of fossil fuels in power plants.
Evaluation of possible solutionsPossible SolutionsStrengthWeaknessPost – combustion carbon capture This process is possible to apply in older power plants. This is because adding a filter is a simple way to trap carbon dioxide as it travels up a smokestack. Carbon capture can prevent a significant amount of the carbon burned in a power plant from entering the atmosphere. ‘In 2017, ADM Illinois Industrial Carbon Capture & Storage Project could capture up to 1.1 million tons of CO2 per year.’ The post-combustion process is inefficient due to high cost and is more difficult to implement due to the compressed the gas being transported to filter. ‘ADOE/NETL analyses suggest that it may increase the cost of electricity for a new crushed coal plant by up to 80 percent and result in a 20 to 30 percent decrease in efficiency.
‘Pre – combustion carbon captureThis process is lower in cost than post combustion because it is unnecessary to compress the gases which are created after combustion.Moreover, it captures a higher concentration of carbon dioxide than post-combustion. ‘In Dakota Gasification plant in Beulah, Over 3 million tons of carbon dioxide per year is captured and transported by the pipeline to Weyburn for EOR.’ It is complicated and hard to implement, especially in older power plants. A catalytic converter can’t be used without changing the original system.
This in turn increases the cost of this process.The cost of this process also discourages the oil industry from investing in this process on a worldwide scale. There is also waste created from these Power plants from the Carbon Infused Water that is left behind.
‘Duke University researchers found the sediments to water solutions infused with large concentrations of CO2 at CCS sites in Texas. The “groundwater” showed concentrations of iron and other metals increased by over 1,000 percent, exceeding safe drinking water standards in some cases.’ The New York TimesThe Clean Power PlanRenewable energy is not associated with pollution, which means no carbon emission occur.
Its strength is that renewable energy facilities such as solar panel and wind turbines are able to be utilized both in household and power plants. Renewable energy is not limited at generating energy as most natural resources cannot be exhausted.The application of it is expensive and would add a cost to the price of facilities built with integrated Renewable energy. Most coal-fired power plants do not try to apply it to them. Solution:To solve this shortcoming, the government can make adjustment about the legislation to subsidize to the facilities that use renewable energy.While there is so much emphasis on the importance of fossil fuels in the current day, it is difficult for renewable energy to gather the support it needs to be the next generation of energy creation.