Carbon capture, utilization, and storage (CCUS) – effective technology or convenient scam?

Brad Hayes examines the effectiveness and limitations of CCUS in curbing greenhouse gas emissions and questions its role, success rates, and implications for energy transition strategies.


Many people in high-income nations (and few in lower-income nations) are concerned about emissions of greenhouse gases (GHGs), particularly carbon dioxide (CO2), and their effects on climate. Behind the media furore and polarized sniping, there are legitimate concerns and scientific discussions around GHGs and their environmental impacts. The precautionary principle says that the less stuff humanity introduces to upset Earth’s ecological balances, the better – so it’s safe to say that reducing anthropogenic (human-made) GHGs and the pollution that often accompanies them is a good idea.

An obvious way to reduce emissions is to make fewer of them. So, we can burn fewer fossil fuels, reduce methane leakage associated with oil and production, raise fewer methane-emitting cattle, and electrify industrial processes. All great ideas. But there are practical limits – after all, fossil fuels still generate about 80% of global primary energy supply, lots of people eat beef, and it is really hard to avoid making CO2 along with cement, steel, biofuels, and other products.

So what else can we do?

We can capture emissions after they are generated, by extracting them from flue gas streams from refineries, power stations, and cement and steel plants. We have got the technology we need, and CO2 concentrations in flue gases are pretty high – 4-12% in simple exhaust systems, 10-40% from cement kilns and blast furnaces, and almost pure CO2 from ethanol and LNG plants. (CO2 concentrations in industrial exhaust streams) We can also try direct air capture (DAC) – extracting CO2 from the atmosphere, so that the extraction facility can be built anywhere and not just attached to an industrial point source. Trouble is, since the atmospheric concentration of CO2 is only about 0.04%, one has to process a LOT of atmosphere to extract any significant amount of CO2.

The easiest way to capture CO2 is to let nature do it as it always has done – plants photosynthesizing CO2, water and nutrients to make leaves, roots, seeds, and wood. We can accelerate natural processes a bit by replanting and otherwise encouraging plant growth. But plant photosynthesis deals with natural carbon cycles – and humanity’s emissions add extra CO2 to natural supplies.

We can capture CO2 artificially (the “CC” in CCUS) by combining it with other chemicals – but what do we do with it then? We have to either use it or inject it into the ground where it can’t escape. 

Utilization, the “U” in CCUS, is a hot topic. Innovators and entrepreneurs are developing new materials and methods to use CO2 to make concrete, polymers, industrial materials, and fuels. Most of these processes are expensive, however, and do not have big enough markets to make much of a dent in our huge output of carbon dioxide.

So we turn to storage, also known as sequestration, to inject CO2 in underground reservoirs – many of the same ones that held and then produced fossil fuels in the first place. We have actually been doing this for decades by injecting CO2 into producing oil pools, greatly increasing the amount of oil extracted – a process known as enhanced oil recovery (EOR). It is counted as “non-conversion” utilization in Figure 1, but it is essentially storage with a purpose.

Storage in depleted oil and gas pools, where pore space in the reservoir formerly occupied by oil or gas is now available, is pretty straightforward. We know how much fluid came out, so we’ve got a really good idea of how much we can put back in. The oil or gas we extracted through wells was stored in the reservoir for millions to tens of millions of years, so CO2 can be stored for a similar time frame, as long as operators ensure their old producing wells are securely sealed.

And there are vastly greater volumes of reservoir space available, currently occupied by naturally occurring, highly saline waters, which have been in residence for up to hundreds of millions of years. CO2 is highly compressible, and can be injected into those reservoirs, either pushing the water aside, dissolving in it, or combining with minerals in the rocks to form new solids.

There is more – investors and operators are experimenting with injecting CO2 into highly reactive rocks such as basalts, where it chemically combines to form new solid minerals. One firm, CO2Lock, has already piloted such a scheme in British Columbia. Carbon mineralization opens up even more sequestration opportunities – including old mine tailings piles.

In summary – CCUS encompasses established, reliable technologies and innovative new techniques to store carbon dioxide safely underground for millions of years. Governments are incentivizing it, research is under way to find more locations and more efficient methods (Energy Innovation Program – Carbon Capture, Utilization and storage RD&D Call), and standards are in place to ensure safety and security, including sophisticated monitoring (Monitoring, measurement and verification principles and objectives for CO2 sequestration projects. Version 2).

So what’s the problem?

The biggest problem with CCUS is not rooted in engineering, geology, social welfare, or business. The International Energy Agency and every other serious energy/emissions forecaster recognize CCUS as an essential component in reducing net future emissions (A renewed pathway to net zero emissions). Government policy in many countries supports and incentivizes CCUS and supporting research, including the Inflation Reduction Act in the United States (Inflation Reduction Act of 2022) and the Energy Innovation Program in Canada (Energy Innovation Program). Alberta has approved 25 carbon hubs as central repositories for CO2, building on huge subsurface datasets and domestic skillsets (Carbon capture, utilization and storage – Carbon Sequestration Tenure).

There are educational programs explaining CCUS in the context of our energy future (21st Century Energy Transition: how do we make it work?) and expert researchers optimizing assessment, execution, and safety, including Dr. Rick Chalaturnyk at the University of Alberta.

Indeed, the negative aspects of CCUS are not material. The problem is in the attitudes of people who do not like hydrocarbons, do not understand CCUS technologies, and are willing to make polarizing statements based on their attitudes, not on fact or scientific and engineering merit.

Here’s an example:

“We’re going to keep burning fossil fuels and somehow magically get rid of the carbon down into the ground where there is no proof that it will stay there, but heaps of proof that it fails … 

“I say for policy makers everywhere do not be the next idiot waiting for the old lie to be trotted out and say I believe in carbon sequestration. It has only failed for 75 years…It’s a complete falsehood.”

– Andrew Forrest, executive chair, Fortescue Metals (Carbon capture tech a ‘complete falsehood’, says Fortescue Metals chairman)

Here is another example from my LinkedIn feed; I won’t embarrass the writer by mentioning his name.

“CCS could only ever attempt to play catch up on the 37 billion tonnes (and rising) of GHGs emitted each year by humankind. Akin to emptying a running bath with a thimble.

CCS … is being used as a salve to allow oil and gas to continue BAU [business as usual] which is diverting the funding necessary to deliver renewable energy that will not pump 37 billion tonnes of CO2 per year into the earth’s atmosphere. 

Here’s the question: Why are we storing tiny volumes of CO2 at massive cost when we could simply use the additional renewables to generate broadly GHG free energy at the lowest cost?”

Anti-fossil fuel advocate and climate crisis promoter Naomi Oreskes chips in with an article in Scientific American (The False Promise of Carbon Capture as a Climate Solution), stating:

“Despite the U.S. government having spent billions on failed CCS projects, under the Inflation Reduction Act, it is set to spend many billions more, a lot of it in tax subsidies to fossil-fuel companies.”

So there you have the arguments – CCUS is bad because:

    1. It can’t sequester ALL of humanity’s GHG emissions
    2. Many CCUS projects have failed
    3. It subsidizes the oil and gas industry
    4. It allows humanity to keep producing oil and gas
    5. We could just use the money to build renewables instead

A little critical thinking leads one to the obvious conclusion that the problems lie not with CCUS, but with the attitudes and false beliefs of the critics. Let me summarize:

    1. Of course, CCUS cannot sequester ALL of humanity’s emissions. Nothing can. CCUS is one of many, many tools that play a role in reducing net emissions – that is why the IEA and others promote it.
    2. Almost all CCUS/EOR projects have been huge technical and economic successes. Some of the early storage projects into aquifers have not performed up to expectations – which is generally true of the first efforts at any new technology. They have not failed in the sense of leaking or posing safety risks – they simply have not stored CO2 as efficiently as operators would have liked.Projects built in the last decade – such as Shell Quest (Shell Canada Energy Quest Project have been remarkably successful, meeting or exceeding objectives. Lessons learned from early experiences guide systematic assessment and engineering work on new projects, which promise to be very efficient and safe.
    3. “Subsidizing the oil and gas industry” is an anti-oil catchphrase looking to create and build on mistrust. Humanity demands oil and gas – and coal, and countless other resources and materials – that produce emissions, and CCUS deals with emissions from all of those industries. Research projects being sponsored by Natural Resources Canada are examining CCUS potential to sequester emissions from industry across the country – power plants, refineries, cement plants, biofuel production, steel mills, and others.
    4. Humanity will continue to produce oil and gas regardless of the success of CCUS – because they provide much of the energy humanity needs to survive. Oil and gas will be produced for decades, because the alternative is death for many of Earth’s 8 billion people.
    5. We are furiously building renewables now – money is not the only, or even the main, obstacle to building more. Supply chains, intermittency, siting and social impacts, and integration into reliable grids are all important factors even with wind and solar’s small penetration into the world energy supply today.

Let’s close by returning to the basic idea here – it is a good idea to reduce GHG emissions, and there are many ways to attack the problem. One can distinguish the best approaches by asking – “How can I maximize emissions reduction for every dollar spent?”

Figure 2 gives us the answer. CCUS is fourth on the list – giving us 3.4 million tons of CO2 reduction for every billion dollars spent. Direct air capture is well down the list – but still a better use of emissions reduction dollars than hydrogen, heat pumps, and EVs with today’s technologies and markets.

Carbon capture, utilization, and storage is an important tool in humanity’s efforts to reduce its emissions of greenhouse gases. While it has limitations, it is one of the most efficient and effective tools we have. Accusations that it is a scam reflect only upon the mindsets and ignorance of the accusers.



Brad Hayes has a PhD in geology from the University of Alberta and is president of Petrel Robertson Consulting Ltd., a geoscience consulting firm addressing technical and strategic issues around oil and gas development, water resource management, helium exploration, geothermal energy, and carbon sequestration. He is an adjunct professor in the University of Alberta Department of Earth and Atmospheric Sciences.

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