What is Carbon Capture, Utilization, and Storage (CCUS)?

Carbon Capture, Utilization, and Storage, commonly known as CCUS, is a phrase you will hear a lot if you are looking into the climate tech space. At its most basic level, it is a series of technological steps designed to grab carbon dioxide before it leaves a factory or power plant. Once that gas is caught, it is either used to make something else or it is buried deep underground so it cannot contribute to the greenhouse effect.

For a founder, this is not just one business. It is a massive logistics and engineering puzzle. You have to think about how to capture the gas, how to move it from point A to point B, and what to do with it once it arrives. It is a multi-stage industrial process that requires a lot of moving parts to work in perfect synchronization.

Building a company in this space is different from building a software app. You are dealing with atoms and physical infrastructure. You are dealing with chemistry and high pressure. You are also dealing with a regulatory environment that is still trying to figure out how to measure success. It is a difficult field, but it is one where the impact can be measured in millions of tons of emissions.

CCUS is generally broken down into three distinct phases. The first is capture. This usually happens at a point source like a steel mill, a cement plant, or a natural gas power station. The technology filters the carbon dioxide out of the other flue gases. This is often done using chemical solvents that bind to the CO2. Once the solvent is saturated, you heat it up to release the pure carbon dioxide for the next step.

This first step is where many startups focus their energy. They are looking for new materials or membranes that can capture that gas with less energy. This is a critical point because capturing carbon requires power. If you use too much power to capture the carbon, you might end up creating more emissions than you are saving. This is often called the energy penalty.

• Post-combustion capture: Removing CO2 after the fuel has been burned.
• Pre-combustion capture: Removing CO2 before the fuel is fully burned.
• Oxy-fuel combustion: Burning fuel in pure oxygen to make capture easier.

The second pillar is transport. Once you have the gas, you have to move it. This usually happens via pipelines, though for smaller operations, it might involve trucks or ships. Carbon dioxide is typically compressed into a liquid-like state called a supercritical fluid to make transport more efficient. This stage is a major infrastructure hurdle for any small business entering the space.

The final pillar is where the “U” and the “S” come in. Utilization means you are turning that waste gas into a product with value. This is a favorite area for entrepreneurs because it provides a clear path to revenue. You can use captured carbon to make things like synthetic fuels, chemicals, or building materials.

For example, some companies are injecting CO2 into concrete as it cures. This not only traps the carbon but can also make the concrete stronger. Others are using it as a feedstock for plastics. The goal here is to create a circular economy where carbon is a raw material rather than a waste product.

Storage, on the other hand, is about permanent disposal. This is often called sequestration. The gas is injected into deep geological formations, such as depleted oil and gas reservoirs or saline aquifers. These formations are usually more than a kilometer underground, far below any drinking water sources. The idea is that the rock layers above will keep the gas trapped for thousands of years.

You might have heard the term Direct Air Capture, or DAC, and wondered if it is the same thing as CCUS. It is helpful to think of them as cousins. CCUS generally focuses on point sources where the concentration of carbon dioxide is very high, like a smokestack. Because the concentration is high, it is technically easier to pull the carbon out of the air stream.

Direct Air Capture pulls carbon dioxide out of the ambient air around us. In the open air, carbon dioxide is very dilute. This makes DAC significantly more expensive and energy-intensive than traditional CCUS. However, DAC can be done anywhere, whereas CCUS must be attached to an industrial facility.

• CCUS: High concentration, lower cost per ton, attached to industry.
• DAC: Low concentration, higher cost per ton, can be located anywhere.
• Both: Require transport and a final destination for the carbon.

For a founder, the choice between these two depends on your focus. If you want to work with existing industrial giants to clean up their operations, CCUS is the path. If you want to build standalone plants that reverse historical emissions, you are looking at DAC. Both are necessary, but they solve different parts of the problem.

One of the biggest hurdles in this field is the business model. Historically, it was cheaper to just vent carbon into the atmosphere than to capture it. That is changing because of carbon credits and government incentives. In the United States, for instance, the 45Q tax credit provides a specific dollar amount for every ton of carbon you capture and store or use.

This turns carbon into a commodity. If you can build a system where the cost of capture is lower than the value of the tax credit or the market price of the carbon, you have a viable business. However, you have to account for the capital expenditure. Building a capture plant requires millions of dollars in equipment. This is not a space where you can bootstrap a prototype in your garage easily.

Startups in this sector often have to partner with large industrial firms early on. You need a source of gas and you need a place to put it. This requires a high degree of trust and long-term contracts. It also means your sales cycle will be measured in years, not months. You have to be prepared for a long haul before you see a return on your investment.

Despite the progress, there are still many things we do not know. One major question is the long-term integrity of storage sites. While geological models suggest the carbon will stay put, we are still learning about how it interacts with different rock types over decades. How do we build monitoring systems that can detect tiny leaks a mile underground?

Another unknown is the true scalability of utilization. We use a lot of concrete and fuel, but is there enough demand to soak up all the carbon we need to capture? If we capture billions of tons, we might quickly run out of things to make with it. At that point, storage becomes the only option, which turns the business back into a cost center rather than a profit center.

We also have to ask about the energy source. If we use fossil fuels to power a carbon capture plant, are we really winning? The math only works if the energy used for the process comes from low-carbon sources. This creates a bottleneck. A CCUS startup is not just a carbon company; it is also an energy management company.

Finally, think about the social license to operate. Will communities accept large-scale CO2 pipelines running through their land? Will they trust that underground storage is safe? These are not engineering problems, but they are just as likely to kill a startup as a technical failure. As you build, you have to think about the people involved as much as the molecules.