Invest in R&D to stay in the carbon capture & storage race
(*Former Advisor, Department of Science & Technology, and CSIR Emeritus Scientist, CSSP, JNU)
Monday, Oct 26, 2009, The Financial Express
While developing countries are expected to take adaptive actions to the pollution that has already occurred, mitigation is an inclusive process and it requires innovation. The science & technology developments have a great role to play in mitigation. The setting up of a national climate change mitigation authority would be a welcome step in this direction.
Take the example of energy sector: Fossil fuels are the backbone of economy of any nation. To address the challenge of emissions from coal-based power plants, efforts are being mounted to introduce carbon capture and storage (CCS) technology as means of effective mitigation option for stabilising CO2 concentrations, either through reduction of emissions or capture of excess CO2. The captured CO2 is converted to liquid form, making it easier to transport it to desirable location. For storage CO2 can be injected into depleted oil and gas reservoirs. The other possibilities are rocks, which react slowly to mineralisation, deep saline formations-underground or under the sea bed.
Pre-combustion appears most favourable to remove or minimise CO2 from the fuel before it is combusted. It is being routinely done for natural gas. Coal needs to be, however, gasified. It would be more appropriate to remove CO2 from the syn gas at higher temperatures of gasification so as to reduce overall energy consumption. The CO2 sequestration studies over a range of different materials; rare earths, composites and adsorbents, which can perform at higher temperatures, have been initiated in R&D laboratories.
In the area of coal combustion the pulverised fuel is the most practical technology adopted in 97% of thermal power plants worldwide. Pulverised fuel under super-critical conditions offers improved efficiency. In India plans are underway to introduce new capacity addition using super-critical boilers. Oxy coal combustion is another innovative technology being proposed in may countries to reduce air pollution and increase efficiency of power generation. Burning of coal in 100% oxygen has benefits as well as technical challenges. Rapid progress has been made in the UK, Germany, Canada and Australia in the last two years as it could facilitate low-cost CO2 capture. A 30-mw oxy coal pilot facility has been demonstrated at Vattenfall (Germany) in 2008.