Queensland University of Technology (QUT) scientists have developed a groundbreaking process. It involves carbon capture that uses CO2 to produce hydrogen and construction materials. PhD researchers Olawale Oloye and Professor Anthony O’Mullane have created the conversion of captured CO2 that generates hydrogen and a host of usable by-products.
“This process involves the capture of CO2 by its reaction with an alkaline solution produced on demand, to form solid carbonate products which can be used, for example, as construction materials, thereby keeping carbon dioxide out of the atmosphere,” Professor O’Mullane said.
The research was published in the journal ChemSusChem, explaining in detail the chemical process.
Carbon Capture And Hydrogen Process Explained
The process takes CO2 and oxygen inputs and combines them in water to produce carbonate ions (CO32-). That happens through a process that involves the electrolysis of water. This electrolysis could be powered by renewable electricity sources like wind and solar.
The carbonate ions are combined with calcium added to the water to produce calcium carbonate (CaCO3). The electrolysis process also produces hydrogen alongside the calcium carbonate production.
The resulting green hydrogen could be used as a fuel resource and the calcium carbonate is an important ingredient in the production of cement. The same process could be used to make many other industrial materials like strontium carbonate and manganese carbonate.
The innovative process could also be used to reduce the CO2 involved in cement production. If the emitted CO2 during the clinking step of the cement production process is captured, it could be used in the mineralization process to produce CaCO3. According to the scientists, in this way a closed loop system is achieved that reduces cement production CO2 emissions.
The researchers also claim they tested the process with seawater to validate it on large-scale carbon capture. They turned CO2 into calcium carbonate with the seawater instead of drinking water. According to them, this is a working “proof of concept of a circular carbon economy.”
“We found we could use seawater once it had been treated to remove sulphates. To do this we first precipitated calcium sulphate or gypsum, another building material, and then carried out the same process to successfully turn CO2 into calcium carbonate” Mr. O’Mullane said.
CO2 reuse has been gaining popularity among researchers and scientists as it provides a particular interest to the industry. Creating CaCO3 while also generating hydrogen in a carbon capture process could significantly reduce CO2 emissions of potentially the entire cement industry.