Belgium company to provide technology to plant in France

By Anna Austin
Web exclusive posted August 22, 2008 at 9:29 a.m. CST

Organic Waste Systems, a Belgium company which specializes in biological treatment of solid and semi-solid organic substrates through anaerobic digestion, has announced it will supply its DRANCO and SORDISEP technologies to Tiru, a subsidiary of Electricité of France, one of the world's largest producers of electricity, to be used at a large-scale digestion plant in Bourg-en-Bresse, France.

Plant construction, which is slated to begin in March 2009, is expected to be completed within two years. The facility will process 90,000 tons of mixed household waste and 15,000 tons of green waste yearly, producing 15 million kilowatt hours of electricity – the equivalency of over 2,640 gallons of fuel daily.

The DRANCO technology is a dry digestion technology to treat organics from municipal solid waste (MSW). It consists of a thermophilic, one-phase anaerobic fermentation step, followed by a short aerobic maturation phase. The waste is treated in two rotating drums for two days to reduce organic fraction, then digested in two silos at 18-134 degrees Fahrenheit for 15 to 30 days, producing 100 to 200 normal cubic meters of biogas per ton of waste.

The SORDISEP (sorting, digestion and separation) technology, which Organic Waste Systems will implement for the first time on a large scale, post-treats the digestate in order to obtain a maximum recovery of recyclables, while minimizing sending waste to landfills. During this wet separation process, glass, plastics and other undesirables are removed by fine screening and other treatment steps. Sticky and odorous components are also removed, as well as organics and cellulose. The remaining materials of sand, fibers and small organics make up the clean compost, which is dewatered and then mixed with a small amount of green waste and composted for two weeks, then cured for six weeks.

Organic Waste Systems provides its anaerobic digestion technology for organic waste, food waste and energy crops to more than 20 full-scale plants in Europe, Asia and the United States. It also monitors and supports 20 biogas plants, treating feedstocks such as manure and MSW. There are three Organic Waste Systems plants currently under construction in Spain, Germany, and Belgium.