Rising carbon dioxide (CO2) emission is increasing the Earth’s temperature. India’s power and industrial sectors contribute to around 60% of the carbon dioxide while the remaining 40% of emissions come from agriculture, transport and buildings. As India’s economy grows, emissions from these sectors are expected to increase too. Thus, in addition to making efforts to reduce CO2 emissions, capturing it from the atmosphere is a way to mitigate the effects of global warming as well as achieve the United Nations Sustainable Development Goal number 13 – climate action.
To mitigate CO2 emissions, India is drafting a Carbon Capture, Utilisation, and Storage (CCUS) policy. It will not only facilitate decarbonization efforts but can potentially kickstart a USD 10 billion industry in next five years, by using captured carbon to make chemicals, among other uses.
What is carbon capture, utilisation and storage, or CCUS?
It is capturing CO2 from large sources such as refineries, cement and steel plants, or power generation units that use fossil fuels like crude oil, coal, naphtha, or biomass as raw material. This captured carbon is then transported by pipeline, ship, rail, or truck to be used in a range of applications or injected for storage into deep geological formations such as depleted oil and gas reservoirs or saline aquifers.
How is CO2 captured?
A key aspect of carbon capture is to first decide where to put it in an industrial setup – pre-combustion (before you burn the fuel/feedstock) or post-combustion. Then comes the process of separating CO2 from other gases. The most common carbon capture method is to fit the technology to the chimney or smokestack of an industrial facility where the CO2 emissions are released.
The technology diverts the smoke containing CO2 before it reaches the atmosphere. A chemical compound such as amine solvent is used to capture up to 95% of CO2 from flue gas. The CO2 is collected and heated to separate CO2 from amine and then put under pressure to turn it into liquid which can then be transported via ships, trucks, pipelines, or injected underground for sequestration. Other separation technologies include using wet scrubbers, solid absorbers, and membranes.
Why is CCUS needed?
India is the third largest emitter of CO2 after China and the US, and has committed to reducing CO2 emissions by 50% by 2050 and reaching net zero by 2070. The power sector alone contributes to about one-third of the aggregate CO2 emissions. The industrial economy emits around another one-third of the aggregate emissions. Even as India makes efforts to phase down the use of coal over time, it will be dependent on it for a long time for affordable and reliable baseload power. Therefore, India’s decarbonisation journey must embrace technologies, like CCUS, that will help it tackle emissions.
What can CCUS be used for?
Captured CO2 can be used for making value-added products and contribute to the circular economy. It can be used to make green urea and green hydrogen. Green urea can replace natural gas-based production and cut India’s imports of ammonia and urea. Captured carbon can also be used for building materials through concrete curing and aggregate formation. In these applications, CO2 is injected in a liquid state without any conversion, thus reducing the energy requirements. For instance, Saudi Aramco, the national oil company of Saudi Arabia, is developing a 9 million tonne per annum CCUS hub in Jubail, Saudi Arabia where it is piloting direct air capture. The company is looking at means of injecting CO2 into concrete.
CO2 can also be converted to methanol and ethanol which have important fuel substitution applications; additionally, methanol is an intermediate for the production of value-added chemicals like acetic acid, and formaldehyde, all of which have multiple downstream applications and offer significant import substitution opportunities which can help reduce India’s import bill. When CO2 is used to enhance oil or gas recovery from matured fields, it’s injected or piped into the field to help the oil or gas flow more freely.
