ABSTRACT
ABSTRACT: The paper shows a concrete way how to solve the environmental problems connected with the treatment of sludge from pulp and paper production with emphasis on sustainability aspects. A thermal treatment unit with a capacity more than 100 tons of wet sludge per day had been completely re-built because of more and more sweeping environmental laws. The retrofit has been realized in three stages as follows: First, environmental problems have been solved by rebuilding incineration and off-gas cleaning systems. The second stage of retrofit can be characterized as a “waste-to-energy” one. Thanks to installing a heat recovery system for preheating combustion air and water for steam generation $ 0.16 mil. is saved per annum. Since the pulp plant is located in mining area the third stage of retrofit consists in substituting the currently used fuel by mining gas containing approximately 50 to 60% of CH4. It results in additional economic and environmental benefit.
