House consumes CO2 by using artificial photosynthesis
Iida Group Holdings Co Ltd (Iida GHD) will test a residential house that consumes carbon dioxide (CO2) by using artificial photosynthesis.
The test will be conducted in collaboration with Osaka City University. The company aims to supply houses that not only reduce CO2 emissions but also consume it by using an artificial photosynthesis technology that uses solar energy to convert CO2 into hydrogen.
This time, Iida GHD and the university developed two kinds of technologies. One is an artificial photosynthesis technology that uses solar energy to generate/store formic acid with a high efficiency and uses it to generate hydrogen. The other is a technology to use the generated hydrogen to generate electricity with a high efficiency.
For the artificial photosynthesis technology, they succeeded in forming a “CO2-formic acid conversion device” powered by solar power on a metal-oxide substrate by using pigments, viologen and formic acid dehydratase. They found that, by using titanium oxide as metal oxide, the efficiency of generating formic acid is improved about six times, eliminating the need for formic acid dehydratase. After that, by using an appropriate viologen, the efficiency was further improved about two times.
As a result, there is a higher possibility that all the electricity consumed by a house can be supplied by (1) installing an artificial photosynthesis-based formic acid generator on its roof, (2) storing generated formic acid and (3) converting it to hydrogen for power generation.
Unlike solar power generation, which causes a loss at the time of charging/discharging electricity, the artificial photosynthesis method generates hydrogen from formic acid for power generation as necessary, eliminating the loss.