Carbon Capture
You’ve probably heard of “clean coal” before, but do you know what it actually means? Unfortunately, it’s not just a shiny piece of coal. The “clean” moniker comes from the process of capturing the carbon dioxide from the waste steam of coal production and storing or reusing it—effectively recycling the CO2 in a process called “carbon capture.”
The United States has actually been using carbon capture for years, since 1997, in fact. It comes with criticism, however, both ethical and economic (more on that later). But any optimistic carbon dioxide reduction predictions from the UN’s Intergovernmental Panel on Climate Change (IPCC) includes significant contributions from carbon capture and storage (CCS) or carbon capture and utilization (CCU). The IPCC is actually relying on substantial advancements, not just in net-zero technologies, but also in negative emissions technologies.
Let’s dive in, shall we?
When we extract oil from the ground, what we’re really extracting is hydrocarbons. When we use that oil, we break the bonds between the molecules, and the carbon (actually, carbon dioxide) is released into the air. When present in the right amounts, carbon dioxide concentration balances the amount of sun that reaches the Earth and the amount of heat that leaves the Earth. Too much carbon dioxide, however, traps excess heat and causes the earth to warm. Carbon capture, as it exists today, is the promise of removing the carbon dioxide from waste steam of burning fossil fuels (catching it before it disperses into the atmosphere) or mimicking the effect of trees and actually extracting carbon dioxide from ambient air (this is called direct air capture or DAC).
Each have their advantages and disadvantages. Flue gas CO2 is more concentrated and the CO2 “filters” are able to be retrofitted to existing coal plants, which is great. But the process of actually removing the CO2 involves a lot of chemistry, solvents, and water vapor which basically means that it takes a lot of energy to capture and condense the carbon dioxide. So we’re capturing the CO2 from burning the coal, but we’re burning a lot more coal to be able to capture it, which is not great. This process is called “post-combustions carbon capture” (because it’s taking place after the combustion process of burning a fossil fuel). There is a “pre-combustion carbon capture” process used in natural gas extraction, but it isn’t able to be retrofitted. Both pre- and post-combustion carbon capture keep 80% to 90% of CO2 from escaping into the atmosphere.
Direct air capture is the process of removing carbon dioxide from the air around us. A company called Global Thermostat has already constructed pilot plants in Alabama and California that work “like a giant lung, but rather than oxygen, [they] take in carbon dioxide.” Since it isn’t dependent on coal or oil production, direct air capture plants can be built anywhere, but because DAC deals with extremely low amounts of carbon dioxide (as opposed to the extremely concentrated flue gasses of fossil fuel plants) it isn’t competitive from a cost standpoint…yet.
The main use for captured carbon is in enhanced oil recovery (EOR). Put very simply, enhanced oil recovery is the process of pressuring CO2 and putting it back into the ground to extract more hydrocarbons from the earth. The carbon dioxide can safely stay underground (assumedly, since it was there for thousands of years before we started taking it out), resulting in carbon capture and storage (CCS).
You might be sniffing out a major argument against carbon capture and enhanced oil recovery. We’re developing technologies to capture carbon from fossil fuel production so we can…increase fossil fuel production? Basically. At the moment, it’s the only incentive that oil and gas companies have to capture carbon. Turns out, saving the earth isn’t reason enough to take on the financial burden of capturing carbon.
But there are other uses for captured carbon! Using CO2 in cement, synthetic fuels, plastics, and other materials could provide an avenue for captured carbon dioxide, turning carbon capture and utilization into a $1 trillion market in only a decade.
The problem is that those initiatives are nowhere near the scale at which we need them to be in order to put a dent in atmospheric CO2 levels. Synthetic fuels probably show the most promise but “[s]ynthetic fuels effectively don’t exist today on any kind of market scale.” And although the market shows promise, it’s basically the worst option of all the possible ways to use CO2 emissions, because the carbon dioxide is released into the environment when the fuel is burned in a vehicle. So the synthetic fuel market is essentially one-time carbon capture recycling.
So we’re left in quite the carbon-heavy pickle. Advocates for CCS and CCU point to the cost reduction in wind and solar energy as a result of policy at the governmental level. Carbon capture and storage could become vastly more affordable if companies were incentivized to do it. Congress passed the Bipartisan Budget Act of 2018 which increased the tax credit per ton of stored CO2 used in enhanced oil recovery and other products. Incentives like these, some say, should be a welcomed piece of the emissions-reducing puzzle, because “oil companies have the equipment, experience, and capital to manage a huge industry like CSS.”
But not everyone agrees. Why spend money on subsidies when we could simply inject that capital into the CCS industry at scale? Why let oil companies determine the point at which they’ll choose to use carbon that has been captured and stored instead of the carbon already present in the ground? The time for tax credits and subsidies is behind us, according to some climate activists. We don’t have the luxury of time to entice the private industry to save the world. Not to mention the ecological damage that fossil fuel extraction inflicts on the environment and surrounding communities.
Clean energy is, indeed, the future. But until we can wean ourselves from fossil fuels, perhaps a tax credit is enough to tip the scales. After all, “[r]eaching net-zero emissions climate goals will require a 100-fold-scale up of CCS facilities between now and 2040, demanding further supportive policies and mechanisms.” The United States is actually home to over half of the 19 commercial CCS plants in the world! ExxonMobil and Chevron have both paired with direct air capture companies (Global Thermostat and Carbon Engineering) in order to increase the amount of captured carbon and decrease the stigma of the fossil fuel industry. Emissions reduction has a lot of moving pieces, and Big Oil has a part to play. How much policymakers allow them to set the rules, though, remains to be seen.