The Paris Agreement made the 194 countries make a promise to themselves and the world- shifting to cleaner fuels and reducing carbon footprints. But on the other hand, countries like India with a huge coal-dependent energy consumption and expenditure needed a method to use fossil fuels while also simultaneously letting off them and not releasing the same levels of CO2 as before.
Amidst major apprehensions on how to proceed,a small plant at the industrial port of Tuticorin is showing the way by capturing CO2 from its own coal-powered boiler and using it to make baking soda.
Crucially, the technology is running without subsidy, which is a major advance for carbon capture technology as for decades it has languished under high costs and lukewarm government support.
The technology gaining traction from all corners of the world, is the brainchild of CarbonClean Solutions, a startup by 2 students of IIT Kharagpur- Aniruddha Sharma and Prateek Bumb. They reversed the mechanics of how to go about CCS- Carbon Capture and Storage in which release of CO2 into the atmosphere is controlled by various means.
Typically, this is achieved by first treating the combustion exhaust gases from the coal plant to remove the small amounts of sulphur dioxide and nitrogen oxides (which can cause undesirable reactions in the next step). Then the remaining mixture, containing mostly nitrogen, carbon dioxide, and water, is passed through a chemical called monoethanolamine (MEA). This chemical reacts selectively with only CO2, and the rest of the gaseous mixture is safely released into the atmosphere. Later, the MEA-CO2 mixture is heated, which releases nearly pure carbon dioxide to be used as a raw material.
Carbon Clean Solutions has synthesized a new chemical, called CDR-Max, that does the job better than MEA. Max is less corrosive too than MEA which protects the steel chambers in which purification is done
Debate over carbon capture has mostly focused until now on carbon capture and storage (CCS), in which emissions are forced into underground rocks at great cost and no economic benefit.
Carbon Storage methods are numerous:
- Can be absorbed by coal beds. Also enhances methane recovery.
- Can be injected into depleted oil and gas reserves below 2600ft
- Dissolved into the sea below 3300 ft via a fixed pipeline or ship
- Released via offshore platform to form ‘lake’ in the ocean bed.
There is already a global market for CO2 as a chemical raw material. It comes mainly from industries such as brewing where it is cheap and easy to capture. Many new startups,along the lines of CarbonClean like Carbon8 have started tapping into this potential market.
Swati Sudhakaran is currently pursuing MA Public Policy at Mount Carmel College in collaboration with the Takshashila Institution.