Carbon Capture and Storage — Definition

Definition

Carbon Capture and Storage (CCS) is a critical climate change mitigation technology designed to prevent large quantities of carbon dioxide (CO2) from entering the atmosphere. At its core, CCS involves three main stages: capturing CO2 from large point sources, transporting it to a suitable storage site, and then injecting it deep underground for permanent sequestration.

Imagine a factory or power plant that burns fossil fuels, releasing CO2 into the air. CCS acts like a sophisticated filter, trapping this CO2 before it escapes. The 'capture' stage is the most energy-intensive and involves separating CO2 from other gases produced during industrial processes or power generation.

This can happen in various ways, such as using chemical solvents that absorb CO2, or physical processes that filter it out. Once captured, the CO2 is compressed into a liquid-like state, making it easier to handle and transport.

The 'transport' phase typically involves pipelines, similar to those used for natural gas, or in some cases, ships. These pipelines carry the compressed CO2 from the capture facility to the storage location.

Finally, the 'storage' stage is where the CO2 is injected deep into geological formations, often thousands of meters below the Earth's surface. These formations include depleted oil and gas reservoirs, deep saline aquifers (rock formations saturated with salty water), or unmineable coal seams.

The CO2 is trapped within these porous rocks, sealed by impermeable caprock layers above, preventing its escape. Monitoring systems are then put in place to ensure the CO2 remains securely stored over geological timescales, typically hundreds to thousands of years.

The primary goal of CCS is to reduce greenhouse gas emissions from industrial activities that are difficult to decarbonize otherwise, such as cement production, steel manufacturing, and power generation from fossil fuels.

It's considered a 'bridge technology' that can help economies transition to a fully renewable energy system by allowing continued use of existing infrastructure while significantly reducing their carbon footprint.

For a country like India, with its significant reliance on coal for energy and rapidly growing industrial sector, CCS holds particular relevance as a potential tool to meet ambitious climate targets without immediately disrupting economic growth or energy security.

However, CCS is not without its challenges, including high costs, significant energy requirements for the capture process, and public perception concerns regarding safety and permanence of storage. Despite these hurdles, ongoing research and development aim to make CCS more efficient, cost-effective, and widely deployable as a vital component of global climate action strategies.