5.4. Management of food waste and composting technologies

LEON MEKITARIAN: Organic recycling is a mucky business. There's no point in being precious about it, yeah? It's dirty. It's smelly. It's basic. It's elemental. Linking what we do back to agriculture is nothing new. The Norfolk four course rotation, on which agricultural fertilizing has been founded since time immemorial, is based on returning organic manures and materials to land as fertilizers. We just got lazy in the last 40 years and bought them from an oil pipeline instead. Currently, food waste is rejected from restaurants, hotels, school canteens, and the kitchen table, put into the domestic refuse bag, and taken away and sent to landfill. Food waste in landfill generates methane. Methane is 18 times more damaging to the ozone layer than CO2 emissions. So every kilogram of food waste that ends up in landfill has the potential to dramatically increase greenhouse gases. Recycling of food waste is one of the most important things you can do. It's better for the environment than changing your car for a hybrid. The great thing about this process is it's self-heating. It's called autothermal thermophilic aerobic digestion. That's a bit of a mouthful. It basically means it's a self-heating compost heap. So, we use minimal energy here and let the bugs do all the work. This is a controlled natural reaction. All we're doing is capturing that reaction, harnessing it, and supercharging it. This plant operates at 75 degrees centigrade, which is a temperature that pasteurizes the food waste material, eliminating all risks of disease and pathogens. It does that by using the naturally occurring bacteria, which we harness in these digestive vessels, and process the waste very efficiently under its own steam. So, there's no artificial heat used in this process, unlike a lot of other technologies, to comply with the regulations which we operate under. We made a conscious decision to locate inside the greater London area. London has a huge food waste problem. There is over a million tons per year. Most of the food waste isn't collected. It goes to landfill. What is collected is transported 60 miles out to Kent and Bedford for treatment. The road miles into our plant are typically eight miles. Waste is delivered into the site, tipped into the silo. The silo moves it to the shredder. The shredder grinds up into little bits. Metals and plastics are extracted. We end up with a thick porridge. These vessels are aerated. And we establish a colony of naturally occurring bacteria, which break down and digest the food waste. At the end of the process, it's stabilized and fully treated. We put it through a de-watering plant and turn it into a solid fertilizer that looks like compost. Our process here is carbon positive in operation. And that stands alone in all technologies that are currently deployed in the UK today. And we achieved that in the main from our end product. Our process in itself is very efficient and has a high throughput, occupies a small footprint and low land use. That's all good. An existing building is also carbon beneficial. But the key element of our carbon positivity is in our end product. Fertilizer that Vertal produces contains all the essential nutrients that are required to grow a commercial crop, be that wheat, be that barley, be that oilseed rape. Displacing the use of petrochemical and derived inputs, which are reliant on oil and gas for their production, and as a result are intensely carbon negative, has huge environmental benefits. Most of the food that is consumed in the world is produced because of the advances made in agriculture since the Second World War. We're now in the post-development phase, where the consequences of the success and the profligacy of the last 50 years are coming home to roost. The world is at a carbon crossroads. Major strategic decisions have got to be made right across the world. What we can do is to start to address the carbon imbalance. We're diverting waste from landfill, reducing carbon emissions in transport. And we're making fertilizer. Waste is a dirty business. People don't want to know, generally. Before recycling, it was all in landfill. It was all causing an environmental hazard. It was causing a smell. It was something that didn't want to be discussed. That's now starting to change. People are much more interested in what happens to the waste. Much more interested in the environmental impacts of waste treatment. And people are becoming more informed. And that's only a good thing. This is part of the sustainable loop. Our process completes the recycling circle. What you scrape off the plate is helping to grow your next meal, your next loaf of bread. It's as simple as that.