Korean researchers find a way to turn seaweeds into hydrogen

A group of South Korean researchers have developed a technology to turn red algae into hydrogen. Professor Kim Sang-hyeon and his team from the Department of Environmental Engineering at Daegu University announced Thursday that they found a way to alter galactose, a main substance of red algae such as agar-agar and Corsican weeds into hydrogen.

Hydrogen is touted as the future of energy as it is three times more efficient than petroleum and it is cleaner than most other sources of fuel. Commercialization has been out of reach, however, as the process required a heavier input of fossil fuel to generate the desired output of hydrogen.

In the U.S., research is making progress on extracting hydrogen from waste wood, but the same model of business could not be implemented in Korea as securing large quantities of wood is difficult in the country.

The research team found a way to utilize red algae for generation of hydrogen, an alternative that is higher in availability and lower in value as resource. They separated hydrogen from galactose. In this process, a constant sterilization was needed to prevent other microorganisms than hydrogen-producing organisms and expedite the reaction process. The researchers came up with an idea to heat up the residues found in sewage at 90 degrees Celsius for 30 minutes before putting them in the reactor.

Following the process, a staggering 74m³ of hydrogen can be generated with 1 ton of dried seaweeds. Given that 1m³ of hydrogen translates into 2kWh of electricity, the new technology will allow 1 ton of red algae to generate enough power for a one-man household to use for a month. The research findings were published on Monday as the cover thesis of the Bioresource Technology, a renowned international journal in the field of bioenergy.

권예슬동아사이언스기자 yskwon@donga.com