Understanding Carbon Capture: The Basics and Importance

We close the special editions of Edges of Innovation by focusing on a technology that promises to get the carbon we emitted in the atmosphere back into the ground: carbon capture. Though promising with incredible engineering challenges and early production sites, can we really scale it? Is it really efficient? This is what we're going to see this week.

What do we mean by carbon capture? Imagine a technology that can trap the carbon dioxide (CO2) emissions from industrial processes and prevent them from entering our atmosphere. This is the promise of carbon capture and storage (CCS), a critical tool in the fight against climate change. In this article, we'll explore the basics of CCS, its types, and its significance in our global climate strategy. Let's dive in and uncover why this technology is essential, yet challenging, to implement on a large scale.

What is Carbon Capture?

Carbon capture involves capturing CO2 emissions at their source—typically from power plants or industrial processes—before they can enter the atmosphere. Once captured, the CO2 is compressed and transported to a storage site, where it is injected deep underground into rock formations for long-term storage. This process can significantly reduce the amount of CO2 released into the air, helping to mitigate the effects of climate change .

Types of Carbon Capture

There are multiple ways to capture carbon as we're going to describe.

Post-Combustion Capture

Post-combustion capture is the most common method and involves capturing CO2 from the flue gases produced after fossil fuels are burned. The CO2 is separated from the other gases using solvents or other chemical processes. This method can be retrofitted to existing power plants, making it a flexible and widely applicable option .

Pre-Combustion Capture

In pre-combustion capture, fossil fuels are partially oxidized to produce a mixture of hydrogen and CO2. The CO2 is then separated before combustion occurs, and the hydrogen is used as a clean fuel. This method is often used in integrated gasification combined cycle (IGCC) power plants and offers higher efficiency but is more complex and expensive than post-combustion capture .

Oxy-Fuel Combustion

Oxy-fuel combustion involves burning fossil fuels in a mixture of oxygen and recycled flue gases instead of air. This process produces a flue gas that is mainly water vapor and CO2, which makes the CO2 easier to capture. The water vapor is condensed out, leaving a relatively pure stream of CO2 ready for compression and storage .

Importance in Climate Strategy

We've seen last week that reducing carbon in the atmosphere is important to limit average temperature increases that could lead to lethal effects for humans. Hence, capturing carbon to bring it back in the ground is crucial.

Reducing Greenhouse Gas Emissions

The primary goal of CCS is to reduce greenhouse gas emissions from industrial sources. By capturing CO2 before it can enter the atmosphere, CCS can play a crucial role in limiting global warming to below 2 degrees Celsius, as targeted by international agreements like the Paris Agreement .

Complementing Renewable Energy

While renewable energy sources like nuclear, wind and solar are essential for a sustainable future, they are not yet capable of meeting all our energy needs. CCS can bridge this gap by reducing emissions from existing fossil fuel power plants and providing a cleaner way to use fossil fuels during the transition to a fully renewable energy system .

Industrial Applications

CCS is not only applicable to power generation but also to other industrial processes that produce significant CO2 emissions, such as cement production, steelmaking, and chemical manufacturing. Implementing CCS in these industries can significantly reduce their carbon footprint and contribute to overall emission reduction goals .

As we've just seen, carbon capture and storage is a promising technology that holds significant potential for reducing CO2 emissions and combating climate change. By understanding the basic principles and types of CCS, we can appreciate its role in our climate strategy. However, as we'll explore in the upcoming articles, implementing CCS on a large scale comes with its own set of challenges. Stay tuned as we go deeper into the current state of carbon capture technologies, the hurdles they face, and the broader strategies needed to make CCS a viable solution for our planet's future.

References

1. International Energy Agency (IEA) CCS Overview

2. IEA Report on Major CCS Projects

3. National Energy Technology Laboratory on Carbon Capture

4. IPCC Special Report on Carbon Dioxide Capture and Storage

5. World Resources Institute on Carbon Capture and Storage

6. Global CCS Institute 2023 Status Report

This article has been written with the help of above references and ChatGPT-4o.