Amid increasingly urgent calls for more radical measures of climate change, a South Korean team of scientists has found a way to kill two birds with one stone by turning carbon dioxide into electricity and hydrogen.
The team, from the Ulsan National Institute of Science and Technology, took as a starting point their research into the fact that when CO2 is absorbed into the sea – where most CO2 emissions end – the acidity level of the water increases. According to their report, "If acidity increases, the number of protons increases, which in turn increases the power to attract electrons. If a battery system is made based on this phenomenon, electricity can be produced by removing CO2. "
The system created by researchers is very similar to a fuel cell where the reaction starts when CO2 is injected into water, which contains the catalyst needed for the reaction and sodium metal cathode. The team reports that the system has a high conversion efficiency of 50 percent and has been operating for more than 1,000 hours without damaged electrodes.
Ideally, this system can be used to capture and convert emissions from fossil fuel-powered facilities to hydrogen, to be used in turn as vehicle fuel. However, this is an initial research. According to the lead author of the study, Professor Jeongwon Kim, "This research will lead to more downgraded research and will be able to produce H2 and electricity more effectively when electrolytes, separators, system designs, and electrocatalysts are improved."
It is good to conduct such research to spur further work in the field and in the end, hopefully, it will lead to a power generation system that can be practically implemented which at the same time reduces the world carbon footprint. However, we have to wait long enough. Related: "Endless Cost Reduction Encourages Renewable Energy Revolution
Systems such as those designed by UNIST scientists rely on carbon capture and storage. This approach to reducing carbon emissions has garnered considerable attention but remains a topic of discussion rather than technology that is being widely adopted. The reason: the cost is very high.
The most expensive part is the catch. The Carbon Capture and Storage Association estimates that the cost of capturing carbon emissions from burning fossil fuels is around US $ 70-102 per ton. The same association estimates this could drop to around US $ 40-57 over the next few years, with the hope that carbon capture technology will follow the path of decreasing the cost of lithium ion batteries. However, it is far from certain that it will work like that.
Back in 2016, the author of Clean Technica, Michael Barnard's business consultant, calculated the total cost of capturing, transporting and alienating (long-term storage) of one ton of CO2 at US $ 120-140. This means US $ 140-164 trillion to capture, transport and absorb more than 1,100 gigatons of CO2 if we want to return to CO2 levels from before the Industrial Revolution, according to Barnard.
In this case the UNIST breakthrough was very important: this eliminated the need to store the CO2 captured for a long period of time. Using it to produce electricity can significantly cut costs associated with all carbon capture and storage problems.
By Irina Slav for Oilprice.com
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