Among the environmentally conscious, carbon dioxide does not have the best reputation. Despite the often beneficial role that it plays in ecology and human industry alike, it is perhaps doomed to be known as the chemical compound that contributes to the infamous greenhouse effect, raising our planet’s temperature incrementally year on year.
Yet carbon dioxide has so many useful applications, not all of which inevitably contribute to the destruction of the planet. Its use as a refrigerant not only keeps white wine chilled to a palatable temperature, but more profoundly this innovation has prevented untold levels of food wastage the world over. When you buy fire extinguishers for a place of work, you are not just ticking the appropriate safety boxes, you’re also preventing the untold pollution that comes from a fire in the wrong place. Without carbon dioxide, those fire suppressant agents wouldn’t even leave the tank. There is also the small matter that it keeps trees alive.
Yet despite its many uses, the scientific consensus is that there remains far too much carbon dioxide released into the atmosphere every year. If the stuff isn’t being used, it’s usually up to no good. Reducing atmospheric carbon dioxide levels has been one of the highest priorities within the scientific community for an awfully long time. And yet, as the prevalence of wind farms and sustainable energy only increases, carbon dioxide trapping (also known as carbon capture) is still too expensive to be rolled out at the levels that UN experts say is necessary if CO2 is to be effectively reduced.
The problem is that the current most popular methods of carbon capture are simply not commercially viable. However, all of that might be about to change in light of a series of new and exciting innovations that have come out over the past couple of months.
Not only are new carbon capture techniques being developed which seem set to reduce the cost down to levels of commercial viability but, increasingly, attention is turning to processes that convert CO2 into less harmful substances (some of which can even be used as fuel themselves).
It is in this new area of CO2 conversion that perhaps the most exciting discoveries have been made, raising the possibility of a cleaner CO2 ecosystem and even attaining a net-zero cycle of CO2 in the atmosphere, with the very CO2 that is released being recycled to fuel the processes which release it.
A New Generation of Carbon Dioxide Traps
As things stand, CO2 capture works by using chemicals, known as amines, which bond to the CO2 and allow it to later be “stripped off” so that it can be stored somewhere other than the atmosphere. The problem is that stripping off the CO2 from these amines (which is also necessary because the amines have to be reused) is an energy-intensive and costly process involving boiling and recondensing the water vapour. The CO2 is then either stored underground (a process that comes with its own costs) or used for other processes.
But now, new “water-lean” capture materials have been developed which, as the name suggests, make use of less water and thereby slash the costs involved in that boiling and recondensing process.
In 2020, companies making use of carbon capture technology managed to capture some 40 million tons of CO2. As things are progressing, another 30 such facilities are planned, which is expected to increase that figure to around 140 million tons. This might seem like a lot, but it is still tiny compared to global emissions, which currently sit at around 35 billion tons. There remains quite a way to go.
The rate of carbon capture needs to be scaled up by orders of magnitude if it is to prove effective in combatting atmospheric CO2. Moreover, for that to happen, the US Department of Energy estimates that the cost per ton needs to fall from its current level of $58 to around $30. Fortunately, it is believed that new carbon capture technologies making use of these water lean amines could indeed affect that cost reduction by reducing the expense of the boiling and recondensing process. To keep up with rates of CO2 release, a deadline of 2035 has been suggested for this to happen. Time will tell if these new technologies can proliferate enough by that date to effect the change needed.
CO2 Conversion
As well as capturing CO2, much effort within the scientific community has been expended on the possibility of converting it into more useful substances. This of course answers the question of what to do with it once it is captured but, beyond that, it all but eliminates the costs of disposing of it. It also produces useable substances in the process.
It was exciting news when a recent research team led by scientists from Argonne National Laboratory, the University of Chicago’s Pritzker School of Molecular Engineering, and Northern Illinois University discovered a new electro-catalyst that can convert CO2 into ethanol in a process that is highly cost-effective.
Carbon dioxide is a highly stable molecule and as a result, converting it into anything has always been an energy-intensive and therefore costly process. With this recent discovery though, those days may very well be at an end.
The catalyst can convert CO2 into ethanol, which has an immediate use as one of the main constituent chemicals of nearly all forms of gasoline and other fuels used in the US today. A massive benefit of adding ethanol fuel is that it makes the fuel burn more cleanly, reducing CO2 emissions into the atmosphere. In this sense, this breakthrough could well have discovered a way to turn CO2 into ‘green fuel’.
Capture and Conversion Working Together
A senior chemist and researcher on the team who made the discovery hopes that the new process could lead to a “circular carbon economy”. One possible application of the new technology being that the CO2 released by jet planes into the atmosphere is ultimately being captured and used to create the very fuel that powers them.
In combination with new and more cost-effective methods of carbon capture, this cost-effective catalytic conversion process could even lead to a situation where CO2 levels released by industry and aviation becoming potentially tolerable.
For that to happen though, the new carbon capture technology needs to become economically viable, providing enough CO2 for that the conversion process to begin in earnest. We are not there yet, but with these new discoveries, humanity’s battle with atmospheric CO2 has reached an important milestone.
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