Energy efficient evaporation in future pulp and paper mills

Paper in proceeding, 2002

In this paper ways to design energy efficient evaporation plants in future pulp and paper mills are discussed. There is more than 1 GJ/ADMT excess heat in the model mills studied that can be made available for use in other parts of the mill. If this heat is used for evaporation and/or if the evaporation plant is designed to use MP steam and deliver LP steam to the steam network, large amounts of steam can be saved. It is shown that these savings lead to reductions in CO2 emissions; the largest reduction are achieved if assuming that oil can be saved or if biomass fuel is exported from the mill and used to replace oil elsewhere. It is also shown that the economic incentive for redesigning the evaporation plant depends on how the saved live steam is used and the economic conditions assumed. The largest savings are obtained if the live steam savings lead to decreased oil consumption. If producing condensing power or excess bark that can be sold, the savings are smaller, but in most cases still considerable in size.