Tackling food waste is currently one of the waste sector’s biggest challenges. While recycling plants are slowly taking shape, there is a very long way to go. A lot of focus is on anaerobic digestion (AD), with the Government providing funding to support the development of new plants. But is focusing on one technology a potential issue?
There is no silver bullet to handling food waste, but there is no denying that AD is the most suitable solution for mixed food wastes due to its low carbon impact. However, it certainly isn’t the only option and for certain types of food chain waste there are more appropriate technologies available that offer better resource efficiency.
The issue that needs to be considered when identifying the most appropriate solution is the energy and calorific value contained within different types of food waste. While this doesn’t mean considering different processes for bread and butter, some food types, such as meat products, have a high fat content which means that they don’t easily degrade during the AD process. However, rendering, the traditional recycling route for meat by-products, can extract this fat and see it reused as an ingredient for new products, such as pet food or ingredients for the organic chemical or biodiesel industries.
Despite the reticence to combust waste, biomass to energy does have a role to play in handling food waste. Food waste isn’t just defined as the edible stuff that comes from supermarkets and homes, indeed there are by-products from every stage of the food chain – be it blood from the slaughtering process or contaminated run offs. These items need to be handled safely and in many instances this is via incineration to eliminate risk of such products entering the food chain.
It’s in the ability to handle food waste crises that AD’s real limitations lie. The BSE and Foot and Mouth crises demonstrated the need for solutions that eradicated contaminated carcasses. Biomass to energy plants were developed following BSE and continue to have a role to play in protecting the long term security of the food chain.
The issue for AD in such instances is the fertiliser produced is going to be primarily used for the growth of new food stuffs. This creates a very positive closed loop food chain, but should there be a food security issue then this could have long term implications and, as an industry, we need to strike the balance between sustainability and security.
What’s most important as we look at how to tackle the UK’s food waste is to make the most of the resource it offers. That is why we shouldn’t just put all our eggs in the AD basket but consider a multitude of options to ensure that food waste has its own recycling hierarchy. For instance the products extracted during the rendering process are used in a multitude of uses which offer greater resource efficiency.
Looking forward, the two prime areas of focus for all sectors, not just waste management, are going to be reducing carbon impact and maximising resource efficiency. Therefore, ensuring we operate a portfolio of different solutions is imperative.