What is the primary purpose of Carbon Capture and Storage (CCS)?

The primary purpose of CCS is to mitigate climate change by preventing large quantities of carbon dioxide (CO2) emissions from entering the atmosphere. It achieves this by capturing CO2 from major industrial and power generation sources, transporting it, and then storing it permanently deep underground. This process is crucial for decarbonizing hard-to-abate sectors and managing residual emissions, thereby contributing to national and global net-zero targets.

How does post-combustion carbon capture work?

Post-combustion capture involves separating CO2 from the flue gases after fuel combustion. The most common method is amine scrubbing, where flue gas passes through a solvent (typically an amine solution) that chemically absorbs CO2. The CO2-rich solvent is then heated to release concentrated CO2, which is compressed for storage, while the regenerated solvent is recycled back into the system. This method is suitable for retrofitting existing plants.

What are the main methods for storing captured CO2?

The primary methods for storing captured CO2 are geological storage, which involves injecting CO2 into deep underground formations. These include depleted oil and gas reservoirs, deep saline aquifers (porous rocks saturated with salty water), and unmineable coal seams. These formations are chosen for their capacity, integrity, and the presence of impermeable caprock layers that prevent CO2 from escaping over geological timescales.

What is the 'energy penalty' associated with CCS?

The 'energy penalty' refers to the additional energy required to operate the carbon capture process. Capturing, compressing, and transporting CO2 consumes a significant amount of energy, which reduces the net power output of a power plant or increases the energy demand of an industrial facility. This penalty can range from 10% to 40% of a plant's gross power output, impacting the overall efficiency and cost-effectiveness of the operation.

How does CCS contribute to India's net-zero goals?

For India, CCS is crucial for decarbonizing sectors heavily reliant on fossil fuels, such as coal-fired power plants, cement, and steel industries, where direct electrification or renewable energy alternatives are challenging or not yet fully viable. By enabling these sectors to reduce their emissions, CCS acts as a bridge technology, helping India meet its Nationally Determined Contributions (NDCs) and progress towards its ambitious net-zero by 2070 target, without immediately disrupting economic growth or energy security.

What are the environmental risks associated with CO2 storage?

While geological storage is generally considered safe, potential environmental risks include localized CO2 leakage. This could lead to soil acidification, contamination of groundwater, or, in rare cases, CO2 accumulation in low-lying areas, posing asphyxiation risks. Rigorous site selection, comprehensive monitoring and verification (M&V) programs, and robust regulatory oversight are essential to minimize these risks and ensure the long-term permanence of CO2 storage.

Can CCS be used to remove CO2 directly from the atmosphere?

Yes, Direct Air Capture (DAC) is a variant of CCS that removes CO2 directly from the ambient air. Unlike conventional CCS which targets concentrated point sources, DAC can capture CO2 regardless of its emission source, making it a 'negative emissions technology'. The captured CO2 is then stored geologically. While promising for achieving net-negative emissions, DAC is currently very energy-intensive and expensive compared to point-source capture.

Carbon Capture and Storage

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India's Updated Nationally Determined Contribution (NDC) submitted to the UNFCCC in August 2022 underscores the nation's commitment to climate action, stating: 'India will reduce the emissions intensity of its GDP by 45 percent by 2030 from 2005 level. To achieve this, India will pursue a low-carbon development strategy, including the promotion of clean and energy-efficient technologies, renewable…

Quick Summary

Carbon Capture and Storage (CCS) is a vital set of technologies aimed at reducing greenhouse gas emissions by capturing carbon dioxide (CO2) from large industrial and energy-related sources, transporting it, and storing it permanently underground.

The process begins with 'capture,' where CO2 is separated from other gases, typically using chemical solvents (like amines for post-combustion) or physical processes. This is often the most energy-intensive step.

Once captured, the CO2 is compressed into a supercritical fluid state, making it suitable for 'transport' via pipelines, similar to those used for natural gas. The final stage is 'storage,' where the CO2 is injected deep into secure geological formations, such as depleted oil and gas reservoirs, or deep saline aquifers, which are porous rock layers saturated with salty water.

These formations are chosen for their capacity to hold CO2 securely, often sealed by impermeable caprock layers. Monitoring and Verification (M&V) systems are crucial to ensure the CO2 remains safely stored and to detect any potential leakage.

CCS is particularly relevant for hard-to-abate sectors like cement, steel, and chemical production, as well as for fossil fuel-based power generation, where direct electrification or renewable alternatives are not yet fully viable or cost-effective.

It acts as a 'bridge technology' to facilitate a smoother transition to a low-carbon economy. Variants like Direct Air Capture (DAC) and Bioenergy with CCS (BECCS) offer pathways to achieve negative emissions.

While offering significant climate mitigation potential, CCS faces challenges including high costs, substantial energy penalties, and the need for robust regulatory frameworks and public acceptance. For India, with its growing energy demand and reliance on coal, CCS is a strategic option to meet its climate commitments and achieve net-zero emissions by 2070, complementing its aggressive renewable energy expansion.

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CCS captures CO2 from large sources, transports, and stores it underground.

Key capture types: Post-combustion, Pre-combustion, Oxy-fuel.

Sleipner (Norway, 1996) was the first commercial offshore CCS project.

Petra Nova (US, 2017) demonstrated CCS with Enhanced Oil Recovery (EOR).

India's NTPC and ONGC are involved in pilot CCS projects.

CCS is crucial for decarbonizing hard-to-abate sectors like cement and steel.

Vyyuha Quick Recall: CCS-3P Framework

P1: Process

Capture — Separate CO2 from gas streams (Post, Pre, Oxy-fuel).

Transport — Pipelines, ships for compressed CO2.

Storage — Deep geological formations (saline aquifers, depleted reservoirs).

M&V — Monitor for permanence and leakage.

Energy Penalty — Significant energy consumed in the process.

Variants — DAC, BECCS, EOR.

P2: Projects

Sleipner (Norway) — First commercial offshore, saline aquifer storage.

Petra Nova (USA) — Post-combustion, EOR linkage.

NTPC (India) — Pilot projects, R&D (NETRA).

ONGC (India) — EOR trials for CO2 utilization.

Global Growth — Increasing capacity, driven by policy.

Indian Context — Focus on hard-to-abate sectors.

P3: Policy

India's NDC — Emissions intensity reduction, non-fossil capacity targets.

NAPCC — Broader climate action framework.

Regulatory Gaps — Need for dedicated CO2 transport/storage laws.

Finance — Green bonds, carbon credits (Article 6), international climate finance.

NITI Aayog — Roadmap, strategic guidance.

Public Acceptance — Key for social license and deployment.

Carbon Capture and Storage

Quick Summary

P1: Process

P2: Projects

P3: Policy

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