Thursday, October 29, 2009
The small town of Ludlow in western England has a pioneering anaerobic digestion plant.
Run by BiogenGreenfinch the plant is intended to deal with the food-waste crisis at the same time as generating clean, renewable energy. The process works by the use of microbes that thrive in the absence of oxygen break down the organic matter, releasing methane as they do so Inside metal tanks.
these microbes are an opportunity in the struggle to deal with unwanted food.
The process starts with the waste being pulverised and then pumped through four processing tanks. These are linked to each other by pipes channeling gas, fluid and solids to their particular destinations.
Once the microbes have completed their job, in about a month or so , the organic waste comes out and farmers collect it and spread it on the land. “The methane is burned to create electricity and hot water, or it can be pumped directly into gas mains, or bottled and used as vehicle fuel.For every ton of food waste, the Ludlow plant generates 255kWh of renewable electricity, which it sells to Marks & Spencer, saving 110kg of carbon-dioxide emissions.”
In addition A government-commissioned study in 2007 identified “that if this system were extended to all households, it could provide between 0.5 and 1 per cent of Britain’s domestic electricity. Plus, this would avoid sending the waste to rot in landfill sites, where the methane can escape into the atmosphere, acting as a greenhouse gas 21 times more potent than carbon dioxide.”
The difficulty is that anaerobic digestion plants are costly to build and complex to run.