Design and management of water circuits of a closed integrated kraft pulp mill

Water use in pulp and paper processes is normally high and highly variable. The reason for the high average water use is the low cost and plentiful supply of water in typical mill locations. In recent years the operating cost of water in pulp and paper mills has been significantly increased due to higher costs of treatment chemicals, pumping energy, discharge liscence fees and effluent management cost. Justifications for water savings is highly dependent on specific mill conditions. Process technologies are available for eliminating the fresh water use completely with the exception of water make-up due to evaporation losses. However, processes will continue to demand water, which in the case of "closed cycle" operation, will be supplied as recycled water.