One man’s trash is another man’s treasure

3 July 2013
Do you remember tyre mountains? Used tyres proved to be a problem to bury in landfill as they were not biodegradable and had an annoying habit of rising up after being buried like something from Dawn of the Dead. Nobody knew what to do with them so they were stockpiled. We also had fridge mountains when we replaced ozone depleting CFC gas with ozone friendly HFC gas - only to discover later the huge global warming potential of HFC meaning one tonne of this stuff in the atmosphere is the same as 2,000 tonnes of carbon dioxide. Not good for the greenhouse effect or climate change. Old fridges were stockpiled while the clever people worked out what to do with them. As we learn more about our environment we throw up new business risks and opportunities. In my public speaking engagements I used to do a routine about ‘myths’, using some very dodgy carbon data to ‘prove’ that a Humvee has a smaller carbon footprint than a Toyota Prius. The purpose was to warn buyers to beware of the information they were being given and to look behind the ‘greenwash’. But in an attempt to help people to understand the environmental impact of their decisions I used to quote as fact “it takes a tonne of carbon dioxide to make a tonne of cement”. Not any more, the fact has turned to myth. The problem with cement is its energy intensity. Lime needs to be cured at over 1,000 degrees Celsius, which needs a lot of energy from burning fossil fuels. I recently visited the country’s biggest limestone quarry and was impressed to see that they now use 60 per cent renewable energy, mostly energy from waste. Old tyres feature strongly in the mix. When burned at high temperature, tyres have a better calorific value and emit less nitrogen oxide than the coal or heavy fuel oil traditionally burned in lime kilns, they are a cheaper fuel source and every bit of the tyre is used, even the steel bands are utilised as it is necessary to introduce steel to the curing process anyway. The fabric embedded in the rubber looks like fluffy cotton stuff when the tyre is stripped out and has an even higher calorific value than the rubber. The problem is lots of industries need to burn things at a high temperature and are looking for lower carbon ways of doing it. The steel and power sectors are also in the market for this valuable fuel so the market has moved from receiving a gate fee for disposing of the tyres to having to pay for them. They are still cheaper than traditional fuels but the rules of supply and demand have caused some price volatility. This has led to the phenomenon of landfill mining, digging up commodities that used to be waste but now have commercial value. I would encourage anybody in the procurement profession to look at waste not as a cost but as potential revenue opportunity. Yesterday’s problem could be tomorrow’s opportunity. ☛ Shaun McCarthy is director of Action Sustainability
Tower Hill, London (Greater)
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St Mungo’s
Yeovil, Somerset
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