What is Carbon Capture, Utilization and Storage (CCUS)? What is the potential role of CCUS in tackling climate change?

Introduction

Carbon Capture, Utilization, and Storage (CCUS) refers to a suite of advanced technologies designed to capture carbon dioxide (CO2) from large point sources (like power plants and industrial facilities) or directly from the atmosphere, followed by its conversion into valuable products or its permanent, safe storage in deep geological formations.

According to the Intergovernmental Panel on Climate Change (IPCC) and the International Energy Agency (IEA), reaching global net-zero emissions by 2050 is virtually impossible without the widespread deployment of CCUS technologies.

Mechanisms of CCUS

1. Capture: Involves separating CO2 from industrial flue gases using technologies like post-combustion, pre-combustion, oxy-fuel combustion, or Direct Air Capture (DAC).
2. Utilization: Converts captured CO2 into economically viable products such as synthetic fuels, chemicals (e.g., urea, methanol), plastics, and building materials (curing concrete).
3. Storage: Involves injecting CO2 deep underground into depleted oil and gas reservoirs, deep saline aquifers, or unmineable coal seams for permanent sequestration.

Potential Role of CCUS in Tackling Climate Change

The role of CCUS in climate mitigation is multifaceted, addressing areas where conventional renewable energy falls short:

1. Decarbonizing 'Hard-to-Abate' Sectors: Heavy industries such as steel, cement, fertilizers, and petrochemicals account for roughly 20% of global emissions. Emissions here are largely intrinsic to chemical processes (e.g., calcination in cement making) rather than just energy use. CCUS is currently the only mature technology capable of achieving deep emission cuts in these sectors.

2. Enabling Negative Emissions: To limit global warming to 1.5°C, merely reducing future emissions is insufficient; historical emissions must be removed. CCUS enables this through:

• Bioenergy with Carbon Capture and Storage (BECCS): Capturing CO2 from biomass power plants. Since plants absorb CO2 as they grow, capturing and storing it when burned results in net-negative emissions.
• Direct Air Capture with Carbon Storage (DACCS): Using large fans and chemical processes to scrub CO2 directly from the ambient air.

3. Retrofitting Existing Fossil Fuel Infrastructure: Developing economies, including India and China, possess a young fleet of coal and natural gas power plants that cannot be retired immediately without threatening energy security and economic growth. CCUS allows for the retrofitting of these plants, significantly reducing their carbon footprint while ensuring a just and stable energy transition.

4. Facilitating the 'Hydrogen Economy': Green hydrogen (produced via renewable electricity) is currently expensive. CCUS enables the production of 'Blue Hydrogen' (hydrogen extracted from natural gas with the resulting CO2 captured and stored). Blue hydrogen acts as a crucial, cost-effective transitional fuel to build hydrogen infrastructure while green hydrogen scales up.

5. Promoting a Circular Carbon Economy: Through the "Utilization" aspect, CCUS turns a pollutant into a resource. For example, using CO2 to cure concrete not only stores the carbon permanently but also reduces the amount of cement required, creating a double climate benefit.

Challenges and Limitations of CCUS

While theoretically robust, the deployment of CCUS faces critical hurdles:

• High Capital and Operational Costs: Capture technologies are highly capital-intensive and consume significant amounts of energy (the "energy penalty"), reducing the overall efficiency of power plants and industrial units.
• Storage and Infrastructure Bottlenecks: Transporting captured CO2 requires extensive pipeline networks. Furthermore, finding geologically stable storage sites without the risk of seismic activity or groundwater contamination is challenging.
• Moral Hazard: Environmentalists argue that heavy reliance on CCUS provides a "license to pollute," thereby delaying the phase-out of fossil fuels and the transition to a purely renewable energy system.
• Technological Immaturity: Except for Enhanced Oil Recovery (EOR), many utilization technologies and DACCS are still in early commercial or demonstration phases.

India’s Context and Initiatives

For India, achieving its Panchamrit target of Net-Zero by 2070 necessitates integrating CCUS.

• NITI Aayog’s CCUS Policy Framework: Recommends developing CCUS hubs and clusters to bring down economies of scale.
• Mission Innovation: India is an active participant in global initiatives to accelerate clean energy innovation, including carbon capture.
• Department of Science and Technology (DST): Has established National Centres of Excellence in Carbon Capture and Utilization (NCoE-CCU) at IIT Bombay and JNCASR Bengaluru.

Way Forward

To realize the full potential of CCUS, a multidimensional approach is required:

1. Carbon Pricing: Implementing a robust carbon tax or an emissions trading system (like the upcoming Indian Carbon Market) to make CCUS economically viable for industries.
2. Hub and Cluster Approach: Co-locating carbon-emitting industries with shared transportation and storage infrastructure to reduce unit costs.
3. R&D and Subsidies: Providing Production Linked Incentives (PLI) or tax credits (similar to the 45Q tax credit in the USA) to encourage private sector investment in emerging utilization technologies.

Conclusion

CCUS is not a substitute for the transition to renewable energy; rather, it is an indispensable complementary tool. While renewables and energy efficiency must lead the global decarbonization effort, CCUS acts as the critical bridge for hard-to-abate sectors and the key to unlocking the negative emissions required to stabilize the global climate infrastructure.