Paul Killoughery, managing director of food waste recycling business, Bio Collectors, looks at the issue of segregating food waste at source and how we can help raise awareness of what happens when it leaves the kerbside.
Attention to food waste has been stepped up on the television agenda and this can only be positive. While not a new issue, we need to encourage everyone to tow the line when it comes to correct and environmentally-friendly waste disposal. In London alone, households are still throwing away more than 7m tonnes of food and drink every year – that’s around 20 percent of all the capital’s domestic waste – and a large amount is not being recycled.
Before we get carried away and think Jamie Oliver and Hugh Fearnley-Whittingstall are going to eradicate the problem entirely we need to look at the bigger picture and how we can help. There will always be a proportion of food and drink products that need to be disposed of. It’s what we do with it that we need to improve.
Of course, as with any type of waste, the primary objective is to prevent or reduce the quantity that is being thrown away, which is what our friends on television are focussing on. If they can help a major supermarket chain reduce its waste by just a fraction, the impact will be substantial.
Lower Down The Waste Hierarchy
However, it’s what happens lower down the waste hierarchy that concerns me most. In England, in 2012, around 40 percent of all residual waste was sent for incineration of which, where no separate food waste collection systems are in place, up to 40 percent comprised food waste.
Waste sector professionals had to change their business models when landfill became unfeasible from both an environmental and cost perspective. However, incinerating food waste should not be regarded as a step in the right direction. With food and drink accounting for 20 percent of the UK’s CO2eq emissions, we need to be looking a much greener processes, and that all hinges on better separation of waste.
Some councils are still to introduce separate food waste collections to households in their areas, which means they simply send all their municipal waste to incineration plants. In London, two incinerators plants alone are burning thousands of tonnes of food and drink, simply because it is mixed with other domestic waste.
To put it into perspective, incinerators emit more carbon dioxide per unit of electricity (2988 lbs/MWh) than coal-fired power plants (2249 lbs/MWh). You may have read a few years ago that, after promoting the use of burning waste, Denmark realised that the process was in fact releasing double the quantity of carbon dioxide than originally estimated. The evidence suggests that despite producing energy, the impact on the environment is predominantly negative.
So why are some councils continuing to use incineration? Is it because it’s easier to just lump everything in together, or is it because it’s too expensive to introduce separate collections? Only the waste decision makers in councils know, but sometimes even they seem unclear just why they are doing something. If every council in London, and further afield, fully separated food and drink from other rubbish the picture would be much more positive. Ultimately, it would allow councils to fully recycle their food waste, at half the cost of incinerating it.
Heavy Investment in Anaerobic Digestion
The government has granted permission over the last couple of years for heavy investment in anaerobic digestion (AD) plants. Investors will have spent £10m or more on these plans and now the government needs to help and aid these plants to ensure that food waste is not going up in smoke.
While complex, the AD process provides a renewable source of energy without any damaging by-products. When it arrives at our plant, waste is cleaned by hand of any large contamination pieces, such as plastic or paper, before being smashed into a soup-like substance in a pulveriser. The material passes into the pasteurisation stage where it is held at over 70°C for one hour to kill any bacteria. From here, the waste moves into our AD tank where it remains for 20 days and at this stage, we start collecting 60 percent methane that is produced.
After some is used to heat our offices, the rest of the 60 percent methane is scrubbed in our bio methane plant, upgrading it to 98 percent. This allows us to pass the gas onto the National Grid where it supplies our local community in Mitcham. In the summer, when demand is low, we supply most of the households and businesses in the area, whereas in winter our reach is slightly smaller.
What remains is a nutrient-rich material that has been in the AD tank for almost three weeks and is compliant with PAS110. Farmers in Surrey and Sussex like the product so much, demand for the product outstrips our ability to supply enough for the farms we work with.
There will be those of you that will argue incineration is at least better than landfill. To which I’d have to agree. The uncontrolled release of methane is the worst possible scenario for our planet. However, why would you burn food waste, creating more emissions, not to mention the ash that needs to be sent to landfill, when alternative processes exist that are far greener and much cheaper?
There appears to be an inherent commercial advantage in not segregating food waste at source, in direct conflict with the spirit of the waste hierarchy. It is clear to me that the general public would not understand why waste is being burnt on an industrial scale when alternatives exist, which are readily available, such as AD.
As an industry, we now need to promote the benefits of separating food waste and raise awareness of what is happening to household waste when it leaves the kerbside, ultimately ensuring that local government is changing its approach to waste management. We’re certainly keen to do that and hope that others will follow.