Greenergy, a privately owned company that supplies one fifth of Britain’s road fuel, has begun producing biodiesel from food waste. In a unique partnership with Brocklesby, a specialist in recycling edible oils, unsaleable food products such as crisps and pies, which would previously have gone to landfill or compost, are now being converted for biofuel and energy production. This new initiative helps to reduce the environmental impact of the fuel that Greenergy produces while also creating a new alternative source of fuel.
Greenergy has invested £50 million in its biodiesel production facility in Immingham on the east coast of England in order to efficiently process used cooking oils, which are more complicated to process than ‘new’ oils such as rapeseed. The company already uses significant quantities (more than 20 million litres a month) of biodiesel from used cooking oil supplied from a range of food producers.
In order to extend its use of waste-based biofuel even further, Greenergy is now beginning to make biodiesel from high fat solid foods such as pies, sausage rolls, pastry and crisps which are not fit for sale because they are mis-shapen, overcooked or past their sell by date. These food products, which typically contain between 25% and 30% oil and fat, are sourced from a variety of food manufacturers nationally. Other suitable foods include taramasalata and oil from fish frying containing high quantities of breadcrumbs.
The oils and fats in these foods are extracted through a novel process developed by Brocklesby and are then further purified by Greenergy. Only then are the oils and fats clean enough to be suitable for conversion into biodiesel. The finished biodiesel is then blended in small quantities into the diesel that Greenergy supplies to petrol stations nationally.
Any food solids that remain after processing are currently dried and then either composted or used to produce energy through anaerobic digestion, but in future could be used to make solid biomass fuel pellets or briquettes, or more fuel for cars in the form of bioethanol. Waste water is used as a biomass crop fertiliser.
“We’ve always tried to find ways of reducing the environmental impact of our fuel and as oil prices continue to rise, it’s obviously important to develop alternative sources of fuel,” comments Andrew Owens, chief executive of Greenergy. “The quantities of biodiesel that we’re currently producing from solid food waste are small, but we’re expecting to scale up so that this soon becomes a significant proportion of our biodiesel.”