Disruptive substances and the burning ­behaviour of solid alternative fuels

Summary: The increasing requirement to use alternative fuels means that rotary cement kilns are being converted to the use of calciners and multi-fuel burners. However, the production of alternative fuels and the process technology must be matched even better to one another if the application rates are to be increased further without affecting the product or the emissions. This includes the fact that the alternative fuels must be characterized and appropriately processed not only chemically in accordance with the requirements of pollution control but also in accordance with the objectives of the thermal utilization process. This article describes the preliminary work and tests involved with the air-whirl-mill. Initial investigations into various pulverized alternative fuels have shown speeds of ignition and conversion that have previously been found only with pulverized coal and lignite.

1 Basic principles

Due to the continuing fluctuations in the price of energy and the debate on sustainable conservation of resources, the German cement industry has managed to decrease its overall energy demand continuously through technical optimization [1]. It has also increased the use of alternative fuels still further under pressure from German policy with the implementation of the ban on landfilling untreated waste (Technical Instructions) in 2005.

 

After the first oil crisis there was initially a changeover from oil to coal and, because of their high energy contents and relative ease of...

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