What is Clean Coal Technology?

Clean coal technology refers to the technologies being developed or implemented to mitigate the environmental impact of coal energy generation and reduce pollutant emissions from coal-fired power plants. Some of the goals of clean coal technology are to reduce sulfur dioxide, nitrogen oxides, mercury and particulate emissions as well as reducing carbon dioxide emissions from coal-burning facilities to help address concerns of global warming and climate change.

Carbon Capture and Storage

One of the most promising Clean Coal Technology being developed is carbon capture and storage (CCS). CCS involves capturing the carbon dioxide emissions produced during coal combustion before they are emitted into the atmosphere. The captured CO2 is then compressed and transported via pipelines to underground geologic formations for long term storage. This prevents the greenhouse gas from entering the air and contributing to global warming. Several pilot projects around the world are working to demonstrate the feasibility and safety of large scale CCS from coal power plants. If successfully implemented at commercial scale, CCS could allow coal to be used as an energy source while addressing climate change concerns.

Improved Combustion Technologies

New combustion technologies aim to burn coal more efficiently and cleanly. Technologies like integrated gasification combined cycle (IGCC) gasify coal into a syngas that can be burned to generate electricity with fewer emissions than traditional pulverized coal plants. Supercritical and ultra-supercritical pulverized coal plants operate at higher temperatures and pressures for increased efficiency which reduces the amount of coal needed per unit of electricity produced. This leads to lower emissions. Coal ignition and micronizing technologies more completely combust coal particles, reducing particulate emissions.

Pollution Control Equipment

Various pollution control devices can be installed on coal power plants to capture sulfur dioxide, nitrogen oxides, particulate matter and other pollutants before they are emitted from smokestacks. Flue gas desulfurization systems use limestone and water to remove over 90% of the SO2 from flue gases. Selective catalytic reduction units employ catalysts to chemically reduce NOx emissions. Electrostatic precipitators and baghouse filters capture over 99% of particulate matter emissions. Sorbent injection technologies can reduce mercury emissions by over 90% through chemical reactions.

Coal Gasification

Instead of directly combusting coal, gasification involves partially oxidizing coal at high temperatures and pressures to produce a synthetic gas or syngas which primarily consists of carbon monoxide and hydrogen. The syngas can then be used in many different ways. Integrated gasification combined cycle (IGCC) plants generate electricity by firing the syngas in a combustion turbine. Future uses being explored include converting syngas to liquid transportation fuels or chemicals. Gasification produces fewer air emissions than traditional combustion and also generates a concentrated stream of carbon dioxide suitable for carbon capture and storage. Coal beneficiation technologies like coal washing can also improve gasification efficiency by removing minerals and impurities from the coal feedstock.

Coal Beneficiation and Upgrading

Beneficiation and coal upgrading technologies aim to modify or physically alter coal before it is burned. Technologies like cleaning, washing, dewatering and drying remove mineral matter, pyrites and impurities from run-of-mine coal. This results in a cleaner burning coal that reduces sulfur and ash emissions. Coal upgrading uses processes like hydrogenation, solvent extraction and catalysts to physically or chemically change the properties of coal, making it burn even more efficiently and cleanly. Beneficiated coal also improves efficiency in gasification applications. Overall, coal beneficiation and upgrading can reduce emissions per unit of energy produced from a given quantity of raw coal.

New Coal Sources: Coal Bed Methane and Underground Coal Gasification

Clean coal research also aims to develop new methods for accessing energy from coal reserves. Coal bed methane extraction involves pumping water from coal seams to capture the methane gas that naturally occurs within certain coals. Extracted coal bed methane can be used as a cleaner burning natural gas. Underground coal gasification involves drilling boreholes into deep unminable coal seams and intentionally combusting the coal underground to produce a synthetic gas without the need for open-pit or strip mining. If developed successfully, these new sources may lead to coal being used with fewer surface disturbances and emissions per unit of energy.

Promising the Future of Coal

While still facing challenges, clean coal technologies show promise for allowing coal to continue serving as a major global energy source well into the future in a more environmentally sustainable manner. Through technological innovation, the substantial coal reserves worldwide could potentially be tapped with greatly reduced pollutant emissions comparable to or better than other energy sources. With further research, development and deployment, clean coal aims to reconcile coal use with concerns over both local air quality and global climate change. Overall, clean coal technology strives to enable a lower carbon future while also potentially preserving jobs and economies dependent on coal as an energy resource.

About Author:

Money Singh is a seasoned content writer with over four years of experience in the market research sector. Her expertise spans various industries, including food and beverages, biotechnology, chemical and materials, defense and aerospace, consumer goods, etc. (https://www.linkedin.com/in/money-singh-590844163)