Tuesday, 26 May 2009


Pyrolysis, the poisoned peninsula and the problems of decommissioning.

The contemporary world faces a toxic legacy: environmental contamination caused by past industrial activities. In Britain most came from gasworks and coke plants which used pyrolysis to convert coal to gas.The by-products of pyrolysis are some of the most carcinogenic compounds known to man. In addition to concentrating pollution geographically, the manufacture of gas and coke displaced it chronologically by creating hazards that would long endure. Today, decades after they ceased production, many of the places where gasworks and coke plants once stood remain contaminated by toxic by-products.

Both the Dome and the Olympic Park had the bad luck to be planned and built on contaminated sites.The experimental nuclear reactor of Queen Mary’s college and its associated contamination provided considerable extra expense for one set of developers and the site of the South Metropolitan Gas company became a nightmare for the Dome builders.

The Greenwich peninsula contained "hot spots" with particularly high concentrations and quantities of hazardous chemicals. One of these was a big underground tar tank which had been shattered by a Luftwaffe bomb. But the chemicals left in the ground by years of spills and leakages dotted around the site had spread widely with the flow of groundwater. One type of waste, a catalyst contaminated with cyanide, was used as a foundation for roads there. The decontamination work has involved pumping up contaminated water and separating out the noxious chemicals, and taking 200,000 tons away in hundreds of lorry loads of the most contaminated soil to landfill sites (where are they now?) at a cost initially projected at 10.5 million but ended up half complete at 185 million.Any further development there can only be strictly curtailed, and a Japanese buyer walked away.

When any modern technology has at its base the physical chemistry process of pyrolysis it has the problem of how to dispose of the ash and tar.First there will be the storage costs,then the decomissioning.Be sure they will be fully accounted for in the contract, and not, like in the nuclear industry, left to be picked up by the local council tax payer.

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