Converting food waste into biogas

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(China Daily)
Updated: 2009-05-22 09:58

SEOUL: The South Korean city of Ulsan lets water generated from processing food waste run off into the ocean, which can generate methane gas harmful to the environment.

Now, with the help of a Swedish company, it is going to converthat waste water into biogas, a type of clean fuel that can be used as power to heat buildings.

South Korea is looking for ways to increase the use of biogas and other clean energy alternatives amid a push by the government of President Lee Myung-bak to embark on a new development model that emphasizes so-called green growth.

Ulsan, an industrial center of about 1 million people on the country's southeastern coast, saw biogas as an attractive way to deal with a burgeoning waste problem as well as tighter government regulations.

"Ulsan is running out of waste disposal sites to cover all the garbage that comes out from the city," municipal official Park In-muk said yesterday. "When garbage is processed into compost, it creates waste water," he said, which the city has been letting flow into the ocean.

The dumping of waste water generated by the processing of leftover food into the sea, however, will be banned from 2013, according to the Ministry of Land, Transport, and Maritime affairs.

The impending ban on the practice of dumping the waste in the ocean also helped spur Ulsan to look for alternatives. It found a partner in Scandinavian Biogas Fuels AB.

The company is based in Sweden, a pioneer in manufacturing and using biogas, which is made by optimizing the decomposition of organic waste that results in a combustible gas that can produce heat or electricity.

Scandinavian Biogas is investing about 10 million euros ($13.8 million) to upgrade a wastewater treatment plant in Ulsan and will soon start accepting food and other waste for processing into biogas, said Scandinavian Biogas President and CEO Thomas Davidsson.

"Producing biogas is a very effective way of taking care of the waste" as it can be used for heat, electricity and vehicle fuel, Davidsson said in an interview on Wednesday. He was in Seoul to participate in the Seoul Climate Change Expo held in conjunction with the third C40 Large Cities Climate Summit.

Turning food waste into biogas can also contribute to efforts to stop global warming.

"If you dump it into the sea, methane will be produced," he said. "And methane released into the air is 21 times more aggressive than carbon dioxide. So it has a great impact on the greenhouse effect."