There is no doubt that coal generates half of the electricity of the developed states and will likely to do so as long as it is inexpensive and abundant. With growing use of coal as source of electrical production, environmental quality is being deteriorated with the pace of time.
The major aim of clean coal technology is to reduce the environmental impact of coal energy production through various feasible techniques or methodologies. We can call it as a collection of technologies being developed to lessen the environmental impact of coal energy production and to mitigate worldwide climate change.
- Techniques of Clean Coal Technology
1- Carbon Capture and Storage Technology:
Carbon Capture and Storage (CCS) is a technology that can capture up to 90% of the carbon dioxide emissions produced from the use of fossil fuels in electricity generation and industrial processes, preventing the carbon dioxide.
The Carbon Capture and Storage chain consists of the three parts; capturing the carbon dioxide, transporting the carbon dioxide and securely storing the carbon dioxide emissions underground in depleted oil and gas fields or deep saline aquifer formations.
2- Underground Coal Gasification:
Underground coal gasification is the promising technology as it is combination of mining, exploitation and gasification. Coal gasification is the process of producing syngas-a mixture of carbon monoxide, hydrogen, carbon dioxide, methane and water vapor from coal and water, air and oxygen.
In current practice, large scale instances of coal gasification are primarily for electrical generation such as integrated gasification combined cycle power plants for the production of chemical feedstock or for the production of synthetic natural gas.
The hydrogen obtained from coal gasification can be used for the various purposes such as making ammonia, powering a hydrogen economy or upgrading fossil fuels.
- Clean Coal Pros:
1, Continuous power
2, Can be made low carbon with CCS and various scrubbers.
3, Substantial existing infrastructure
4, Clean Coal Technology is being used mostly in China.
5, Relatively low capital investment as compared to gas or nuclear.
- Clean Coal Cons:
1, Coal is non renewable
2, Coal is largest contributor to Global Warming.
3, High cost of Transporting coal to centralized power plant.
4, Clean coal is not carbon free
5, Sequestration is new and expensive. Its ability to hold carbon dioxide for long periods of time unproven. Risk of accidental releases of large quantities of Carbon dioxide.