Clean coal sounds like it is the perfect answer to our energy problems. Instead of continuing to burn fossil fuels in coal production, we can still access coal but in a clean way that doesn’t hurt the environment, right? Wrong. Turns out, clean coal is not all it promised it would be.
What Is Clean Coal?
The current production process of coal releases toxic emissions into the air. As the dirtiest of all fossil fuels, coal directly contributes to air pollution, water pollution and acid rain. Coal generates half of the energy in the United States and 92% of US coal goes into producing electricity.
The idea behind clean coal technology is to use modern technology to clean the coal and contain the harmful emissions. This would ensure that the environment is not negatively affected and we could continue using coal energy until we run out.
Ways to Clean Coal
Clean coal relies on modern technological practices to try and keep coal burning as harmless as possible. Here are four types of clean coal technology:
Coal washing is a method for cleaning coal before it is burned. It is the process of removing certain toxic minerals from the coal before burning. This is achieved by mixing crushed coal with a liquid which allows the impure minerals to separate and settle.
Other clean coal technologies work to minimize the emissions (sulfur dioxide, nitrogen oxide and particulates) that come off burning coal. Wet scrubbing (or flue gas desulfurization system) removes sulfur dioxide by spraying flue gas with limestone and water. Sulfur dioxide is a major cause of acid rain. Low-NOx is similar to wet scrubbing but attacks nitrogen oxides by restricting the amount of oxygen and changing the combustion process.
Lastly, gasification is the clean coal process that avoids burning coal all together. Instead of burning coal, steam and hot pressurized air combines with coal to force the carbon molecules apart. This mixture is then cleaned and burned in a gas turbine to create electricity.
Mississippi Clean Coal Power Plant Fails
So while the idea of clean coal technology and the methods in place may sound good, they don’t work out as well in practice. Energy company Southern Co. and Mississippi Power have been working on building a clean coal power plant in Mississippi since 2010. But in early July, they decided to pull the plug on the project and potentially suffer a $3.4 billion loss.
So what went wrong with the clean coal power plant? This project in Mississippi was doomed from the start. As soon as construction began, Southern Co. learned that their design plans were wrong and their budget quickly ballooned from an estimated $3 billion to over $7.5 billion. Southern Co. also overestimated the price of natural gas, meaning their clean gas project became uneconomical.
The clean coal power plant in Mississippi was planning to use the gasification method of cleaning coal. The plan was to turn the coal into gas before burning it to be used for electricity. The carbon dioxide removed from the coal would then be pumped underground so it wouldn’t be able to contribute to global warming. Unfortunately, climate experts have said that coal gasification has never been used to produce commercial electricity. The Mississippi power plant was attempting to take on the impossible.