Climate change and energy are two areas that are intertwined in a very deep way. Data shows the most common methods of creating useable energy are contributing in some way to changes in the atmosphere, because of the carbon dioxide (CO2) being emitted. One way to address this problem is with carbon-capture technology that filters the CO2 out of the emissions of fossil fuel power plants, for safe storage. This technology is often very expensive, requires large amounts of energy, special chemicals, and additional hardware at the plant. Researchers at MIT however thought of an interesting way to solve this problem by getting power plants to emit pure CO2, while also increasing efficiency, at a low cost.
Instead of filtering the emissions of the power plant, the plan is to filter the air coming in for combustion from the normal 78% nitrogen, 21% oxygen combination to pure oxygen. To accomplish this, the researchers used a ceramic membrane that only lets oxygen pass through it. The researchers found the oxygen flow stops when the oxygen level of both sides equalizes, so they built a combustion system into their test reactor, to keep an oxygen differentially on the two sides of the membrane. This creates a "win-win situation" as the filtering the oxygen out to fuel the combustion is what allows more oxygen to be filtered. Also, by incorporating these two components into the same device it allows the system to be very small and very efficient, both in terms of energy and economy.
With the combustion fueling the process of oxygen retrieval, there is the potential for a chain reaction that gets the combustion going very hot as more and more oxygen feeds it. Though the ceramic membrane can withstand very high temperatures, the researchers did find the temperatures exceeding their tolerance. Ironically though, the flow of oxygen through the membrane was actually creating a protective layer to prevent the ceramics from overheating. So the system feeds itself and protects itself.
So how does this system of creating a pure carbon dioxide stream help combat climate change? It is much easier and cheaper to capture the all of the emissions of a power plant than to capture just part of it. This solution is essentially a pre-filter that may enable future fossil fuel power plants to become carbon neutral, or very close to it, and retrofitted power plants to do the same. Before we can see those power plants though, more testing has to be done to show the entire setup is durable enough to survive the operation of a power plant.