By Emily Newton
Carbon capture, utilization and storage (CCUS) could be the key to halting climate change, but only if carbon can be reused responsibly.
In recent years, carbon capture has moved to the forefront of climate change discussions. Various technologies have been tested to remove carbon dioxide directly from the atmosphere, creating products that are carbon neutral or even carbon negative.
Such technologies have received support and funding from large corporations and governmental agencies. However, climate change experts, scientists and activists are divided on whether carbon capture will be beneficial in the fight against climate change. Few technologies have yet to reach commercial scale, and most still have obstacles to overcome.
How Does Carbon Capture Work?
There are several approaches to carbon capture and utilization employing a variety of technologies. Chemical absorption is the most common and has been in use the longest. This process uses a solvent to separate CO2 from the air and capture it. Physical separation is also in use at several plants, which involves various absorption methods, including cryogenic separation, dehydration and compression.
In general, however, most carbon capture techniques follow a similar approach to drawing carbon from the atmosphere or the flue gas streams of carbon-intensive industrial applications. Once isolated and collected, it is transported via pipelines to its next destination. Sometimes CO2 is sent directly to a secondary use or destination, but other times it must be contained and conveyed on a ship, truck or train.
Captured CO2 can be used in many ways. Often it is simply stored underground, such as in emptied natural gas reservoirs. CO2 requires specific conditions to be successfully and safely contained this way.
A carefully controlled series of physical and chemical processes must be applied to the CO2 to ensure it doesn’t leak into the ground or water supplies, where it could harm the environment. To help achieve this in reservoirs and pipelines, engineers have begun using special corrosion-resistant alloys that are more secure, especially when chemical processes come into play.
Applications of Captured CO2
Although some captured carbon can be stored deep underground, it is not feasible to do this with all the CO2 captured each year. There are several ways it can be reused. This is helpful for carbon-capturing facilities since it brings in money that is instrumental in sustaining operations.
Carbon has great potential for use in creating synthetic fuels, including gasoline and jet fuel. They still generate carbon emissions, but they are much cleaner than traditional alternatives. This is especially true considering carbon was removed from the atmosphere to create the fuel.
Typically, these synthetic fuels are hydrocarbons, a blend of hydrogen and CO2. However, the adoption of this application has flattered, largely due to a lack of support from government agencies, which tend to prioritize renewables like solar and wind.
Agriculture, Food and Beverage
Captured CO2 is more often sold for various commercial purposes. In agriculture, this includes applications like accelerating the growth of such applications in greenhouses. The food and beverage industry uses CO2 for carbonation, such as in seltzer and soft drinks.
Enhanced Oil Recovery
The most controversial application for captured CO2 is enhanced oil recovery. This is also the largest market for captured CO2. Fossil fuel companies pump it into oil wells to make the petroleum deep underground float to the surface easier. This allows more to be pumped out of the ground in less time, creating even more greenhouse gas emissions.
Green construction companies are testing methods of using CO2 to create highly durable, carbon-negative concrete. It’s estimated to be 30% stronger than traditional concrete and doesn’t rely on cement, which produces half of the carbon emissions in this industry.
This could be incredibly beneficial in the fight against climate change. The CO2-based concrete uses less cement and limestone, reducing its initial carbon footprint and price. It also removes CO2 from the atmosphere and locks it away where it can’t do any more damage. The result is true carbon-negative concrete, which could take hundreds of megatons of CO2 from the atmosphere every year while supporting the booming construction industry.
Bioplastics and Carbon Fiber
Captured carbon can also be used to create sustainable versions of common materials, such as plastic and carbon fiber. Several companies have already found a consumer market for these materials. For example, Newlight Technologies captures CO2 from farm and flue streams and uses it to create durable bioplastics. Global furniture brand IKEA has invested in the technology and utilizes these bioplastics in many of its products.
Similarly, captured carbon is a key component of carbon composites, which are ultrastrong metal alternatives. These materials can be used in everything from airplane turbines to bicycles. Carbon nanofibers are strong on their own, but using captured carbon to create them allows composite companies to reduce expenses significantly.
Challenges of Carbon Capture
Despite good intentions, CCUS has not yet rallied unanimous support from climate scientists. While most would agree that it is necessary to remove CO2 from the atmosphere, many are skeptical of the business model for carbon capture plants. This gets to the root of the problem: Removing CO2 from the atmosphere is expensive.
Controversial Uses for Recaptured Carbon
While fighting climate change is certainly not a business, the reality is that such facilities are expensive to build and to operate. To fund these projects, they need to have some way to bring money back in. The obvious solution is finding a purpose for the captured carbon, such as those mentioned above.
Industry leaders have discussed the difficulties of establishing a revenue stream for carbon capture sites. While selling the CO2 for synthetic fuels is generally the preferred route, there is simply not a large enough market for this.
Carbon capture is not classified as a renewable energy source. Some projects have benefited from government subsidies and incentives but few have reached the level of commercial viability that they can attract investment. This leaves many facilities to turn to other methods of income, such as enhanced oil recovery.
Since enhanced oil recovery enables fossil fuel companies to be more productive and sell even more fuel, it creates more emissions than what we removed from the atmosphere. This essentially negates the whole process of carbon capture. As a result, many in the climate science community question the ethics of the carbon capture business model.
If the captured carbon is being sold back to the companies that created these emissions, is helping to solve the climate problem? Some operators have started refusing to sell CO2 to oil companies, but this would need to become the standard for carbon capture to gain more support.
Large Scale Governmental Support and Incentives
One of the key issues the industry faces is government support. For carbon capture to significantly impact climate change, it needs to be in use on a far greater scale than it is today. Pulling CO2 out of the atmosphere is necessary for meeting climate goals. Even if renewable energy were to become the norm overnight, there is already an immense amount of carbon dioxide in the air.
Climate change policy has advanced significantly over recent years, with important initiatives like the Paris Agreement and even the Biden administration’s green energy goals in the U.S. However, the focus has remained on renewables rather than carbon capture.
While green energy is certainly a crucial element of effective climate policy, carbon capture needs to be included in the government incentives that help support renewable power growth and environmental action.
Money is at the heart of the industry’s carbon problem. With increased federal support, Carbon capturing facilities might not have to consider enhanced oil recovery as a source of income. While it is not yet feasible to have a 100% government-funded carbon reuse network, the aid could give carbon capture the starting boost it needs. Canada is already experiencing rapid growth in carbon capture infrastructure funded by billions of dollars of government investment.
One way to accomplish this may be to stimulate growth in these technologies is through government mandates requiring the use of captured carbon in certain products or services. It could be mandated to be used in new public infrastructure projects. This will result in stronger concrete, more resilient structures and green economic growth. Schools could use furniture made from durable bioplastics containing captured carbon.
Synthetic fuels might take off, as well, if carbon capture was qualified as a renewable energy source. Biofuels could help phase out and replace fossil fuels, starting with government-owned vehicles.
Public demand for climate action may encourage more government bodies to implement policies like this. Voters will be happy to hear that their tax dollars support carbon-neutral and carbon-negative projects. Mandates will result in more physically resilient communities, offering tangible benefits in addition to environmental ones.
A Crucial Opportunity With Carbon
Despite the controversy, carbon capture, utilization and storage is an opportunity to fight climate change that the world cannot afford to pass up. To truly heal the environment, we must work to repair the damage already done to the atmosphere and prevent the release of more emissions.
Carbon capture technology is the opposite side of the same coin that renewables are on. These technologies are crucial to winning the fight against climate change and creating a clean, sustainable future.
Emily Newton is a journalist with over four years covering the environmental sector. As Editor-in-Chief of Revolutionized, she also covers the many ways technology is changing our world.