Part 1: How Is It Meant To All Work?
I wanted to write up a quick effortpost on carbon capture as someone more than a geological layperson but admittedly less than a specialist. Opinions about carbon capture range from a Muskian tech-bro belief in its emancipatory role in solving the climate crisis to a belief that it is an almost entirely failed technology that will only exacerbate emissions. It would be exceptionally boring of me to say, "Well, carbon capture is a land of contrasts…" and as such, I will show my hand immediately and say that I come down much closer to the latter belief than the former, but there is genuine nuance to understand about the technology. I hope to make the current state of things a little clearer.
I will have to simplify things for brevity and clarity; many long reports, papers, and books have been written on the subject, which adds all sorts of complications. You could (and many have) dedicated your academic and professional life to the field and its inner workings. But I hope this suffices, and I hope users arrive with more knowledge, or information to add or correct.
A Quick Explanation of the Theory
Your typical CCS project can be divided into three sections - the first is the capture of CO2; the second is the transportation; and the third is the storage - or, a not-so-secret fourth option, the utilization (such as in chemical processes or oil recovery). While the more accurate name for the process as a whole would thus be CCUS, and that acronym is what you'll see a lot of if you delve into the science, CCS works fine for our purposes.
Capture: Carbon dioxide is somehow captured or separated from other gasses, usually at a stationary source like a factory or a fossil fuel power plant. There are many technologies for this, like absorption, adsorption, and cryogenic separation, but this isn't the essay's focus. The efficiency of capturing this carbon is not (and never will be) 100%, and in some case studies I've seen figures as low as like 30%. 90% capture efficiency is an often-boasted number. In short: it depends, and as we'll see later, it's not the most burning question in the CCS debate anyway.
Transport: The carbon dioxide is liquified and then moved through pipelines. Humans have gotten pretty good at moving liquified gases through pipelines, so this is the least problematic part of the process in terms of the science. Of course, there is inevitably an environmental impact from pipeline construction and the possibility of leakages.
Storage/Utilization: This liquified carbon dioxide is injected into sinks, typically underground deposits or aquifers, or used in further processes (though this currently makes up a negligible portion of captured carbon usage - it turns out that other sources of carbon are not very hard to come by). The big argument here, and the one I was told when I was taught about it in my courses, is something along the lines of "Look - if this reservoir was able to hold this natural gas/oil for millions of years, then it can continue to hold carbon dioxide for millions of years more." While this isn't always true - seismic activity and the impact of previous oil extraction operations might produce ...interesting results down the line - the theory is relatively sound, especially with frequent monitoring.
So, this is how it's meant to work - you stick a filter of some kind on a power plant or cement factory or steelworks or something, you transport it via pipeline or perhaps other methods, and then you stick it underground where it will stay for thousands or millions of years in the same place that we got the fossil fuels from in the first place. It's an idea that is convincing in its simplicity, and - hypothetically - it requires no extra space that needs to be constructed by humans. Indeed, there are appropriate geological traps that we could put the CO2 into that didn't already have fossil fuel present due to being at the wrong depth or not having the right biological material there, so even if some reservoirs were too damaged by extraction, we could still put the carbon somewhere.
The International Energy Agency is certainly a believer in the potential of the technology, featuring it as part of its roadmap towards net zero by 2050, and has various other pieces more explicitly on the role of CCS as a technology that can both reduce emissions directly and remove CO2 already emitted from the atmosphere. The IPCC, the body dedicated to climate change at the UN, also regards carbon capture as a critical technology.
As such, CCS is increasingly finding its way into countries' and companies' climate policies. 24 out of 29 Long Term Low Emissions and Development Strategies submitted under Article 4 of the Paris Agreement have CCS as part of their strategies.
Natural Gas and Enhanced Oil Recovery
Before I discuss the problems with CCS, a brief note here on what "enhanced oil recovery" is and how CO2 and natural gas relate to it. Natural gas must be processed before it can be marketed and sold and said processing involves separating CO2 from the gas mixture. This CO2 is thus captured and sent to be used in enhanced oil recovery, which has helped boost the economic viability of natural gas extraction.
Enhanced oil recovery is the process by which you inject CO2 into existing oil and gas reservoirs to use the pressure to extract more fossil fuels, improving production rates, particularly in reservoirs in which extraction is declining. Not only are you using (typically non-renewable) energy to compress carbon dioxide into liquid form and then pump it into the rock, but the extra oil and gas you get out of the rock is being used as fuel, which worsens the climate crisis.
Part 2 here in the comments.
Part 2: The Bad News
Mostly Failures
Let's delve into some examples of CCS use cases and, along the way, discover how and why the technology is not working as envisaged by people who care about the climate:
Shute Creek, a natural gas facility commissioned by ExxonMobil in 1986, was one of the earliest - and one of the largest - attempts at CCS, and before the focus of CCS was on solving the climate crisis. When first proposed in the early 1980s, oil prices were high, so the idea was to transport this CO2 to oilfields to help boost oil extraction. Once oil prices returned to normal and boosting oil extraction in this way became uneconomical, the excess CO2 was vented into the atmosphere in place of any underground formation to put it in. Nonetheless, it remains one of the largest single carbon capturers on the planet, capable of sequestering 7 million tonnes per year, albeit with 50% of that captured carbon entering the atmosphere soon after. If we're being complimentary, it demonstrates the technology's potential.
Onwards to Norway. Ten years after ExxonMobil's fascinatingly pointless facility was constructed, the Sleipner project was established in the North Sea - a significant gas field for the UK and Europe - this time designed to put the CO2 in a deep reservoir with a projected capacity of 600 billion tonnes of CO2. However, the project can only inject about a million tons per year. The Norwegians managed to get the design right, with no leakage from the reservoir, and as such, it's now the poster child of what can go right with CCS. Ten years after this, the CCS project Snøhvit was commissioned in the Barents Sea and was similarly successful, though with half the injection rate. The Norwegian carbon tax introduced in 1991 ensured that the money lost by the company for venting the CO2 was considerably more than the cost of storing it underground.
With Norway's Sleipner as a CCS success story, Algeria's In Salah comes along as another one of failure. After beginning injection in 2004, the project was suspended seven years later due to concerns about reservoir leakage. However, it did at least manage to store about 4 million tons of CO2 before it went kaput.
The Australians considered Norway's success and constructed their own natural gas and CCS project, Gorgon, in 2016. Despite initial optimism, technical problems with the pipes and the wells associated with CO2 injection stretched for years while the plant continued extracting the natural gas. It has captured only 5 million tons of CO2 as of 2021, falling short of its 10 million ton target.
In 2013, the United States tried to establish a CCS project in Wyoming called Lost Cabin, which could inject about a million tons of CO2 per year… which was then suspended after five years due to a fire. Additionally, this was for enhanced oil recovery.
The power sector has only a few carbon capture projects despite comprising a large portion of humanity's emissions. One of these projects, Petra Nova in Texas, was a retrofit designed to take CO2 from the power plant and… pipe it to an oil field for use in enhanced oil recovery at a time of high oil prices at the time of proposal. You can guess what happened next - oil prices fell, and then 3 years later, the plant shut down during the pandemic after injecting 20% less CO2 than was planned, or 3-4 million tons of CO2.
A more dramatic failure in the US was the Kemper "clean coal" project, designed to show the world that coal could be made to burn more cleanly by siphoning off the CO2 pre-combustion, and… yes, you guessed it, send it to enhance oil recovery somewhere else. After over doubling in cost from $3 billion to $7 billion and being delayed for years, the carbon capture portion of the project was canceled. Perhaps it was doomed for failure - the plant's fancy gasification and carbon capture parts required 30% of its power output, compared to just 3% for the typical power plant's internal machinery.
The Boundary Dam CCS project in Canada was established in 2014, and since then has captured about 4 million tons of CO2 and only has about half the actual CO2 injection rate that was initially promised. This CO2 was used, again, for enhanced oil recovery.
As for the uses of CCS in industrial projects, to give a decent selection, we have:
a) The Athabasca Oil Sands project in Canada extracts CO2 from an oil facility. It injects it underground at a rate of about a million tonnes per year, for a projected total of 27 million tonnes of stored CO2. It is remarkably on track for that goal if one discounts the energy needed to run the CCS equipment in the first place.
b) The Great Plains Synfuels Plant in North Dakota takes CO2 from a coal gasification facility and uses it for enhanced oil recovery for nearby oil fields.
c) The Illinois Industrial Carbon Capture and Storage project takes CO2 from ethanol production. It injects it into an underground reservoir, capturing 1 million tons annually (out of 4.5 million tons emitted by biofuel production).
d) The Coffeyville Resources Nitrogen Fertilizer Plant in Kansas, from which CO2 is extracted for enhanced oil recovery in Oklahoma.
e) The Abu Dhabi CCUS Plant in the UAE, which captures CO2 from the flue gas of a steel production facility for use in enhanced oil recovery, with limited data on its performance.
Scale and Cost
These projects are fairly representative of the state of the CCS industry as a whole. As can be seen, these projects are usually either total failures, partial failures, or failed from the outset from the perspective of reducing emissions because of the CO2's use in boosting oil extraction elsewhere - and, due to market fluctuations, even those projects can fail.
Approximately 75% of the CO2 injected via CCS projects in recent years goes towards enhanced oil recovery projects. This isn't a previously morally pure technology being corrupted by fossil fuel executives - the beginnings of CCS, dating to about 50 years ago, are fundamentally linked to furthering oil and gas extraction. Before 2000, almost 100% of the carbon capture projects on the planet were dedicated to natural gas processing leading into enhanced oil recovery or venting directly into the atmosphere - today, their prominence has only declined to 70%. The origins of CCS coincide remarkably well with the 1970-80s oil crisis, in which US oil producers looked to increase extraction efficiency with CO2 injection to solve supply shortages.
Even for the projects that succeed, the rates at which they inject CO2 are too low to be of any consequence. Consider the following:
Somewhere in the realm of 2000 billion tonnes of CO2 has been emitted by humanity, with about half staying in the atmosphere. Every year, we emit about 35 billion tons of CO2. The IPCC has estimated that 5-10 billion tonnes of CO2 must be removed from the atmosphere every year in the second half of the 21st century to keep warming at the 1.5°C mark. ExxonMobil's own figures suggest that to date, humanity has stored about 300 million tonnes of CO2.
Therefore, our total combined efforts over the last 50 years of CCS development is to sequester 3-6% of the CO2 that we need to sequester in a single year, according to the IPCC, or just 0.8% of the CO2 that we currently produce every year, or 0.03% of what humanity has emitted since the Industrial Revolution. And, again, a very large proportion of that stored CO2 is being used to increase the efficiency of fossil fuel extraction and not for climate mitigation.
Even if the technical problems with CCS can be mitigated and improved on - and I hope they can be - the issue of funding these projects is a simply monumental endeavor. If we aim to bring the CO2 concentration in the atmosphere back down to pre-industrial levels, then the size of the CCS industry will necessarily have to receive a similar amount of money and development as the fossil fuel industry does for an industry that is entirely unprofitable if not being used to boost the extraction of fossil fuels, and which would require vast amounts of energy to run - energy which obviously cannot come from fossil fuels.
This is impossible in a market-based economy dependent on the profit motive. As seen above, with its carbon taxes and strict environmental laws, Norway was about the only major success. Yet, it is several orders of magnitude away from removing even a small portion of annual emissions from the atmosphere. So: what about China?
China is making progress in the field of CCS but is still only really in the beginning stages. As of the beginning of 2023, China's capture capacity is at 4 million tonnes per year, and its injection rate is at 2 million tonnes per year. Nonetheless, there are about a hundred CCS demonstration projects at various scales and phases throughout the country, ranging from 100,000 tonnes to a million tonnes, and even to 10 million tonne projects with the backing of CNOOC, Shell, and Exxon. The problems CCS outlined above cannot be dealt with by any single country. Still, hopefully, China can produce some interesting results on larger scales than seen currently and advance the science for later use in a world socialist system.
Therefore, our total combined efforts over the last 50 years of CCS development is to sequester 3-6% of the CO2 that we need to sequester in a single year, according to the IPCC, or just 0.8% of the CO2 that we currently produce every year, or 0.03% of what humanity has emitted since the Industrial Revolution. And, again, a very large proportion of that stored CO2 is being used to increase the efficiency of fossil fuel extraction and not for climate mitigation.
God that outlook seems bad. 3-6% so far of what we need, how is that going to ramp up to 100% in the next 5-10 years? I can't see it happening fast enough. It simply won't.
From the “IPCC working group 3: Climate Change and Mitigation, Summary for Policy Makers”, I get the sense that most Carbon Capture projects in the west are designed to give the oil and gas companies hand outs so they agree to some of the mildest of carbon controls. By the IPCC own account, the repossession of land, and the mass planting of trees are better at carbon storage and a more cost effective investment. The industrial carbon storage plans allows existing oil and gas companies to make even higher profits.
I find that the IPCC reports are extremely helpful, but reading between the lines shows just how afraid of capital they are.
https://www.ipcc.ch/report/ar6/wg3/downloads/report/IPCC_AR6_WGIII_SummaryForPolicymakers.pdf
On page 41 is a figure showing the positives and negatives of each tech.
