Rubbish is a burning issue
Published 02/05/2009 | 00:08
The proposed incinerator for north Belfast is intended to burn rubbish and harness energy from the resulting heat.
Rubbish is made up of glass and metals which don’t burn. Food wastes, textiles, papers and plastics burn, but need to be very dry, around 18% moisture content, to ensure clean, efficient combustion.
Food wastes have around 90% moisture, so needs drying. The energy needed to
achieve this has to be subtracted from the energy provided. If you add transport energy to and from the incinerator (rubbish in/ash out) the sums look different.
Food, sewage and farm wastes can be gasified in localised anaerobic digesters providing town gas and dry fertilizers, remembering that our agriculture uses nitrate fertilizers made of imported oil.
For three tons of rubbish burned, we get two tons of toxic ash and one ton of toxic air.
Do we invest in environmentally productive waste treatment or incineration?
I really can’t see the economics. Interest rates are low and inflation is rising so money in bank accounts is melting in value.
Materials such as textiles, glass, steel, copper, aluminum, timbers, plastics, compostable foods and garden wastes are getting scarce and more valuable, so why burn them?