The capital of Japan's Saga Prefecture is using the carbon dioxide and heat emitted by its waste disposal plant to cultivate crops and grow algae.
The Saga City Waste Incineration Plant uses technology developed by Toshiba Energy Systems and Solutions to burn household waste.
The plant then sells the resulting carbon dioxide and heat to farming operations, sending them to greenhouses via pipelines.
Alvita Corp., a joint venture between Sincere Corp. of Japan and Heliae Corp. of Gilbert, Ariz., grows haematococcus, an algae found in nature throughout the world, is one recipient of the carbon dioxide.
Growing algae requires water, sunlight and carbon dioxide for photosynthesis, said Yasunobu Katsuki, Alvita manufacturing department director and engineering section chief.
The company extracts from the algae the chemical astaxanthin, an antioxidant used as an ingredient in health food and cosmetics, which it sells.
The algae, each one-tenth of a micron, is first cultivated two to three weeks in cylindrical plastic bags in the company's "bag room," where it is fed carbon dioxide.
"In the room, there is less danger of contamination from mold, dust, et cetera," Katsuki said.