The bio-fertiliser from Willen Biogas near London has now received the coveted British accreditation BSI PAS 110. The biogas plant produces biogas and bio-fertiliser from source separated food waste collected from the London area, and the quality stamp ensures that the bio-fertiliser from the plant can be used safely on farmland.
Food waste from restaurants, commercial kitchens and supermarkets in London is currently being used to produce biogas and bio-fertiliser at Willen Biogas, which was constructed and put into operation by Xergi in 2016.
Willen Biogas has now demonstrated that the plant can provide high quality bio-fertiliser, having received the demanding BSI PAS 110 accreditation.
The fundamental idea behind using food waste for biogas production is that the biogas plant can ensure that the nutrients in the food waste are recycled back into agriculture. In particular, this helps minimise the demand on the earth’s phosphorous resources, which are scarce and non-renewable. Therefore, it is important to ensure that the bio-fertiliser from the plant can be used safely on farmland, and this approval is now in place with the BSI PAS 110 accreditation.
The accreditation imposes strict requirements on the quality of the bio-fertiliser. For example, this applies to the level of impurities, consisting of plastic, metal and the like (etc.), which should not end up on farmland.
“Obtaining the accreditation involves a very stringent procedure. You cannot just get it by showing that you have a new plant and explaining how you will run it. When the plant is in operation, you have to prove that the requirements are being fulfilled over a period of several months, during which the plant must be in stable operation,” says Jørgen Fink, country manager for Xergi in UK.
The key advantage of accreditation is that the farmers can feel confident that they are receiving high quality bio-fertiliser.
At the same time, the biogas plant does not have to handle the digestate in accordance with the waste legislation, which otherwise can make the use of digestate in agriculture rather challenging.