Carbon capture is controversial, but it could be crucial

By Tianyi Ma, RMIT University

Cutting emissions alone cannot reduce the build-up of carbon dioxide

Renewable energy sources like wind and solar are essential tools to help us reduce the 36 billion tons of greenhouse gases we emit each year.

However, renewables alone cannot get us to net zero. Sectors such as cement, steel and chemical production produce significant carbon dioxide emissions that are difficult to eliminate through renewable energy alone.

This is why carbon capture, utilization and storage has its place. This technology – invented by the oil and gas industry – is the best solution we have today to capture these emissions at their source, before they can enter the atmosphere.

Environmentalists have long been skeptical of carbon capture, warning that it could be used to extend dependence on fossil fuels. It’s a matter of politics – the science is clear. For now, we will have to capture carbon.

While essential, adoption of carbon capture technology has been slow. As today’s new report shows, we remove just two billion tonnes of CO2 from the atmosphere each year – and almost all of it by planting trees. So far, carbon capture accounts for less than 0.1%.

How does carbon capture and storage work?

This technology was first used in the 1920s to separate carbon dioxide from methane in fossil gas deposits.

In the 1970s, it was used to increase oil production – if you separate the CO2, it can be pumped back into the oil field and extract more. The world’s largest carbon capture operation to date is taking place in Western Australia, where a global oil company is pumping carbon dioxide filtered from natural gas back underground.) This story is why there is so much skepticism about this technology.

This isn’t entirely fair. The technology itself is neutral. If we detach it from history, we will be able to better assess its value.

Carbon capture and storage offers the opportunity to capture carbon dioxide emitted during the production of cement and iron/steel. Together they account for approximately 15% of total global emissions (8% and 7.2% respectively).

What do we do with all the carbon we capture?

Once we capture carbon dioxide, we can use it in industrial processes such as chemical synthesis and food preservation. This approach can reduce emissions while creating added value if waste CO2 can be used to obtain valuable products.

Alternatively, it can be stored deep underground in stable geological formations such as porous sandstone covered by impermeable rock, or in salt caves, natural or man-made. Here it should remain for hundreds of years as a gas. In some places, carbon dioxide can react with minerals to form stable carbonates, effectively turning CO2 into rock.

Carbon capture and storage can be relatively easily added to existing infrastructure such as fossil fuel power plants, oil and gas fields and gas compressor stations, thus offering a transitional path to clean energy.

Upgrading existing power plants with capture and storage technology can significantly reduce emissions without having to immediately decommission plants that are still in operation.

What if carbon capture is a fig leaf?

Critics of carbon capture argue that the technology will likely be used to extend the use of fossil fuels, rather than to phase them out as quickly as possible. From this perspective, carbon capture would be used by fossil fuel power plant operators and companies as a way to make coal or gas “green” and delay a full transition.

This concern is valid. There is a risk that leaders in fossil fuel-intensive industries may see capture and storage as a way to continue their operations with less pressure to innovate or reduce their dependence on fossil fuels, just as some have adopted carbon offsetting to avoid fundamental changes .

However, this does not mean that we should abandon this technology. While we currently have good opportunities to produce emission-free electricity, we do not yet have many options for solving the problem of industrial emissions. Although fossil fuel-free methods of producing steel and cement are emerging, change is slow and the problem of climate change is urgent.

Carbon storage a must for net zero emissions

Authorities from the Intergovernmental Panel on Climate Change to the International Energy Agency recognize the inescapable role of carbon capture and storage.

The European Union’s Green Deal highlights the role of carbon capture in reducing industrial emissions, while the United States has introduced tax breaks and financing to accelerate its adoption.

Last year, the Australian government invited companies to investigate 10 coastal sedimentary basins for possible carbon storage. However, this is not suitable everywhere – the Queensland Government recently banned the technology across the Great Artesian Basin due to concerns about the gas’s impact on groundwater.

How can we make the most of carbon capture technology?

To bring carbon capture and storage to the scale it needs, effective policy support will be needed, such as tax breaks, subsidies and research and development funding to drive innovation and reduce costs.

As part of my research, I worked with industry partners to find ways to use carbon capture in useful ways. If a waste product has value, there is an immediate incentive to use it. For example, I have worked on converting carbon dioxide into “solar fuels” such as green methane and methanol.

It’s more about fixing the future than renewable energy

You would think that the future of energy would be solar, wind and storage. But it won’t be that simple. It will be harder to wean ourselves from fossil fuels than we think. We will need green hydrogen for industrial uses and to produce ammonia for ecological fertilizers. We will need to increase carbon capture and storage for industrial emissions.

We may not like the idea of ​​carbon capture and storage, but we will need it if we are to get serious about net zero emissions. There is currently nothing like it for hard-to-contain sectors. We must avoid using it to support fossil fuels.

Bottom line: Carbon capture plays a key role in achieving net zero emissions of the greenhouse gas carbon dioxide.


Tianyi Ma, Distinguished Professor of Chemistry and Renewable Energy, RMIT University

This article is republished from The Conversation under a Creative Commons license. Read the original article.