Most efforts to capture and reuse carbon dioxide produce more carbon dioxide than they capture, and they are not able to reduce enough emissions to meet the Paris Agreement's goals, said researchers from Radboud University, the Netherlands.
The researchers also cautioned that the technologies which seem to be adequate are often not ready in the commercial marketplace.
Carbon dioxide capture and utilization (CCU) works by capturing carbon dioxide emissions from industrial emissions, and then utilize them to produce chemicals, fuels, and other materials. Although the concept appears to be promising, according to New Scientist, Radbud University researchers discovered that 32 out of 40 technologies produced more carbon than they captured. Only four technologies produce very little carbon and are ready to be put into practical use.
Environmental scientist Kiane De Kleijne, the study's first author, remarked, “We know that the chemical reactions involved consume energy, and that captured carbon dioxide is frequently emitted after being utilized in a product. As a result, we needed to access the real carbon dioxide reduction.”
Most CCU approaches, the scientists found, will not be able to reduce industrial CO2 emissions sufficiently in time.
The researchers looked at how effective CCU technologies were at reducing emissions over the course of the entire operation. Many of the CCUs studied include energy-intensive capture and conversion components, and when the last step of the cycle involves the manufacture of something like methanol, the consumption of the product causes emissions as well. “They don't always lower emissions compared to the traditional product, which is an issue,” added de Kleijne.
The study warns that the focus on CCU technologies may draw attention away from more effective emission reduction strategies such as permanent carbon storage and consumption reduction.