CCUS technology has been talked about since the 1970s. However, in the last few years, it has become a part of the mainstream conversations on decarbonisation.
According to the International Atomic Energy Agency database, CCUS capacities currently in operation globally measure up to 50 million tons per year with individual projects in countries such as Brazil, the US, and Australia each capturing more than three million tons per year.
Let’s explore CCUS technology and its significance.
What is CCUS?
CCUS refers to an array of technologies designed to capture carbon dioxide (CO₂) emissions from large point sources such as thermal plants, oil refineries, and the steel and cement industries. The captured CO₂ is either transferred into the earth or reused for industrial applications in various forms.
The key objective of CCUS is to prevent CO₂ from being released into the atmosphere. In doing so, it interrupts the cycle of carbon that contributes to the greenhouse effect and global warming.
Three stages of CCUS technology
CCUS technology comprises three stages. The first stage involves the capture of carbon, the second its utilisation and the third its storage. The three stages are explained below.
First stage: The first stage involves the capture of carbon. There are different types of carbon capture technologies, and their use is determined by the nature of the gas stream and the intended application. For instance, when the gas streams contain lower concentrations of CO₂ – such as flue gas streams in refineries – the chemical-solvent based capture technology is preferred.
But for gas streams with relatively higher concentrations of CO₂, physical solvent methods are preferred. This is commonly seen in gasification projects associated with thermal power plants. Finally, adsorption techniques are used to capture carbon when gas streams contain moderate CO₂ concentrations such as Steam Methane Reforming (SMR) flue gas.
Second stage: The second stage involves the utilisation of captured carbon. As far as the costs of capturing carbon are concerned, gasification processes cost the least as carbon capture is already integrated into most of these systems. In comparison, coal-based plants, which emit low CO₂ concentrations, incur higher costs.
In the second stage, the captured carbon is converted into value-added products such as green urea, dry ice, carbonated drinks, building materials and chemicals.
Third stage: Finally, the third stage entails storing the CO₂ in saline aquifers, depleted oil and gas fields, and other similar geological formations.
Is CCUS a definitive solution?
Internationally, CCUS has been legitimised as a key technology to tackle climate change. The idea was further endorsed at the 28th Conference of Parties (COP28) held in Dubai in 2023. The application of CCUS technology has shown both promise and hesitancy.
For instance, the UK has had a turbulent history around the application of this technology. Although the government has shown interest in using this technology, actual applications are by far minimal. Two major funding projects got cancelled in 2011 and 2015 due to very high commercial costs and risks. Since then, the government has been working towards incentivising its economy to venture into this sector.
In 2024, the country prepared itself to deploy its first two CCUS clusters. However, the debate about whether CCUS is the answer or not still continues.
CCUS for cleaner energy
Amidst the growing efforts towards net-zero emissions globally, the narrative around CCUS technology has gained significant momentum in India – the third largest emitter of carbon dioxide in the world after China and the US.
At the 26th Conference of Parties (COP26) in Glasgow in 2021, India pledged to achieve net-zero emissions by 2070. Since then, several steps have been taken to meet this target – one such is the growing emphasis on harnessing CCUS technology.
In November 2022, NITI Aayog published a report outlining the potential of CCUS technology in India and a possible roadmap for its deployment. The report was prepared in collaboration with a corporate entity, Dastur & Company Pvt. Ltd., that specialises in clean energy systems worldwide. Here are some of the key highlights of the report:
Decarbonisation of the industrial sector: CCUS has tremendous potential for reducing emissions in hard-to-abate sectors such as coal, steel, cement, oil refineries, which form the backbone of Indian industry. As these sectors will grow in the coming decade, the CCUS technology will help determine the long-term viability of industrial development in India.
Access to renewable fuels: The captured CO₂ can be converted into green fuels such as hydrogen, green ammonia, methane, etc. Thus, CCUS also plays an important role in facilitating the transition to cleaner energy sources and complementing options like solar and wind power.
Challenges
Although CCUS technology has received global endorsement and holds considerable promise for helping India meet its climate targets, it is not without challenges.
High costs and risks: Both scientists and investors have raised concerns about the effectiveness and reliability of CCUS. Since most of the science behind this technology is in a relatively early stage, there are not many success stories that can be replicated.
For instance, Direct Air Capture (DAC) – a method that captures carbon directly from the air regardless of the source or concentration – is in its nascent phase. Most DAC systems largely exist in theory or scientific papers and have been demonstrated successfully in controlled laboratory conditions. Therefore, more research is needed.
Policy push to increase investment: Since CCUS technology remains a niche area, it has yet to attract significant businesses and investors. While coal gasification, hydrogen, and methane are said to be sunrise sectors, investments in them seem unlikely to increase without targeted policy support.
The NITI Aayog report recognises that a multi-pronged policy approach is needed to develop the CCUS market. Recommended measures include tax and cash credits to investors, early-stage financing options for projects, options for public-private partnership, easy procurement of raw materials, Production Linked Incentives (PIL) schemes, etc.
Why CCUS needs more than just capture
Experts have cautioned that even with CCUS technology, carbon abatement will be modest unless the three components of this technology –– capture, usage and storage –– are effectively integrated.
Moreover, the ‘storage’ component (i.e. carbon sequestration) has several issues in India – such as lack of data, the limited availability of aquifers (underground layers of water-bearing rock) and similar geological formations.
Hence, a well-defined and clear strategy is needed for the permanent disposal of captured carbon. This is specifically important because, despite its history marked by both promise and hesitation, CCUS continues to receive attention both globally and in India.
At the same time, given that the dominant approach to climate action is shaped by the logic of neoliberal economics and technocratic solutionism, it is important to critically examine how these technological interventions (such as carbon capture) might affect different sections of society.
Post Read Questions
What is the Carbon Capture Usage and Storage (CCUS) technology? Explain its three key components.
Evaluate the feasibility of the Carbon Capture Usage and Storage (CCUS) technology in helping India achieve its net-zero emissions goal.
To what extent is CCUS a technically viable solution for India’s hard-to-abate industrial sectors, and what are the major barriers to its large-scale deployment?
How effective are current government schemes and incentives (such as PLI, tax credits, PPP models) in attracting investment in CCUS-related sectors?
What kind of policy architecture is needed to create a viable CCUS ecosystem in India, and how can it balance environmental goals with economic pragmatism?
(Aishwarya Sanas is a doctoral researcher at Shiv Nadar Institution of Eminence, Delhi NCR.)
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India has introduced several initiatives to achieve net-zero emissions by 2070 - one of which is the emphasis on harnessing Carbon Capture Usage Storage (CCUS) technology. 
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