Carbon Capture and Storage

Context: 

In its latest review of scientific research, the Intergovernmental Panel on Climate Change (IPCC) found that Carbon capture and storage will be needed for emissions that are hard to wipe out.

Image Source: BBC

About Carbon Capture and Storage (CCS):

• It is a climate change mitigation technology where CO2 is captured from power plants and other industrial processes instead of being emitted to the atmosphere. 
• The captured CO2 is then stored in the subsurface with the goal of keeping it out of the atmosphere indefinitely.
• CCS can be seen as a bridge technology, allowing for the continued use of fossil fuels in electricity generation and industry until low-carbon alternatives can be implemented. 
• CCS may also be necessary to achieve the negative CO2 emissions required for the 1.5°C and 2°C climate goals

CCS Operations 

• Three major parts: 
  1. CO2 capture at a large stationary source (e.g., coal-fired power plant)
  2. Transport of the captured CO2 to a storage site
  3. Injection of CO2 into the subsurface for permanent storage. 
• Capture occurs either through chemical transformation before the fossil fuel is combusted (precombustion) or through physiochemical processes (e.g., adsorption) from the flue gas.

Applications of CCS: 

• Industrial sectors: CCS can significantly reduce CO2 emissions from large-scale industrial facilities, such as cement factories, and steel mills.
• Enhancing Energy Security: CCS can be applied to fossil fuel power plants, allowing for continued use of these resources while minimising their environmental impact
• Agriculture: Capturing CO2 from biogenic sources such as plants and soil to boost crop growth in a greenhouse.

Limitations of CCS:

• Cost and Energy Intensity: It requires significant upfront investments for capturing, compressing, transporting, and storing CO2. 
  • CCS consumes a portion of the energy produced by power plants, leading to reduced efficiency and higher costs of electricity generation.
• Leakage Risk: It is crucial to identify suitable storage sites and ensure the integrity of storage reservoirs to prevent any leakage.
• Limited Scope: CCS is primarily designed for point-source emissions, limiting its applicability to diffuse sources like transportation or residential sectors.

Difference with Carbon Dioxide Removal (CDR):

• In this, carbon is sucked out of the atmosphere.
• CDR brings down the level of carbon dioxide in the atmosphere, cooling the planet, while CCS in fossil fuel plants and factories prevents the gas from getting out in the first place.

How well does CCS work?

• For decades, engineers have captured carbon from concentrated streams of gas — pushing it into tanks, scrubbing it clean and using it in industry or storing it underground. 
• Some bioethanol plants, where the gas stream is pure, already report capturing more than 95% of the carbon emissions.
• While capturing carbon from dirtier gas streams, like those from factories and power plants, CCS projects have repeatedly overpromised and underdelivered.
• Some kind of chemical is needed to grab CO2. This technology has been successfully demonstrated — but it hasn’t been fully commercialised at scale.

News Source: Indian Express

DOWNLOAD PDF