Yesterday, Martin Kriegner of the Austrian cement industry association unveiled a study commissioned from the University of Vienna showing how the industry could increase its waste burn. Mr Kriegner said: "A large part of the thermal energy requirements for the manufacture of cement can be covered using high calorific value waste. The cement industry has the technical know-how and capacity to recover large quantities of waste without leaving residues".
In Austria, the industry currently covers 27% of its energy requirements from waste such as old tyres, waste oil, solvents, packaging plastics and cellulose, with estimated savings of 75,000 tonnes of coal a year. Mr Kriegner said that the proportion of waste in its fuel could be raised to 70%, although this would require new legislation since current Austrian law only allows a maximum of 40%.
As well as cutting coal consumption and fossil CO2 emissions, the association claims that increased waste burning would mean Austria would have to build fewer dedicated waste incinerators to meet the requirements of new legislation due to come into effect on 1 January 2004, banning high calorific value waste from landfill sites. However, since the industry currently consumes only 1% of burnable waste in Austria, tripling its take would seem unlikely to significantly reduce the need for new capacity.
The Austrian environment agency has broadly welcomed the industry's initiative, as long as hazardous wastes do not increase emissions such as heavy metals or contaminate cement products.
However, critics claim that burning waste in cement kilns - known as co-incineration -will increase environmental impacts, particularly through higher emissions of nitrogen oxides (NOx) (ENDS Daily 11 May 1999). Under Austrian legislation, dedicated waste incinerators are allowed to emit 100 milligrams per cubic meter (mg/m3) of NOx. The limit for cement kilns burning waste is 800 mg/m3.
According to an official at the federal environment agency, tests with catalyst technology at a cement kiln in Austria have shown that NOx emissions can be reduced to 200 mg/m3.
Austrian cement industry association, tel: +43 1 5993 215; Technical University of Vienna, tel: +43 1 588 010; Austrian environment agency, tel: +43 1 31304.
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