Looking at the figures of food wastage in the UK, something clearly needs to be done – we throw away £10.2bn of avoidable food waste every year. This equals 16-18 million tonnes of waste food that is buried as landfill each year.
Sweden is a nation which intends to lead the world in renewable fuels. It is not surprising then that it is one of the leading countries in turning leftovers into – yes - electricity. This is the start of a new generation – anaerobic digestors (AD).
Don’t be afraid – it is not a new exercise regime. Anaerobic digestors produce fertiliser and biogas, a mixture of methane and carbon dioxide, which is burnt to generate renewable electricity. Through a biological process similar in many ways to composting - bacteria break down organic matter and reduce its bulk or “mass”.
The world market for biofuels has expanded rapidly in recent years as a combination of domestic politics, rising oil prices, increasing concerns about global warming, and potential economic opportunity have spurred a broad range of countries to pass laws that support biofuel industries.
The Waste & Resources Action Programme (WRAP) with funding from Department for Environment, Food and Rural Affairs (Defra) has supported a number of local authorities to conduct trials of food waste collections in the UK. These trials have involved the separate weekly collection of food waste for either in-vessel composting or anaerobic digestion from over 94,000 households.
Joan Ruddock, the Environment Minister, quoted in on Times online explains that anaerobic digestion is extremely attractive: “Why would we go on throwing food waste into holes in the ground when we could generate our own electricity and end up with a product that can be returned to the soil?”
Yes, you might be thinking, compost smells. However, the digesters will be located in the suburbs because unlike previous models, the new units are not reliant on farm slurry to provide moisture for the recycling process. Without the smelly transportation of animal waste, the prospect of plants in urban areas, will, the Government hopes, be a lot easier for residents to digest.
Related Research: World Biofuels: Forecasts for 2012 & 2017 in 17 countries
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October 24th, 2008 at 9:56 am
There is a reasonable amount of waste food that could be used to produce biofuels. Digesters are one part of the answer perhaps. Another useful part could be the use of pyrolysis to convert the remaining biomass into gasses. These gases could be burned directly (like old fashioned town gas from coal) or converted into liquid fuel. There would still be the problem of disposing of the ash from this process but the volume would be considerably smaller than the volume of landfill. Such a two-pronged attack on the situation would yield more biofuel than simply digesting and would reduce volume.