System closure in integrated newsprint mills: review of R&D issues

System closure in integrated newsprint mills should be performed gradually, to allow for assessment of its effects on pulp and paper operations. Compu ter simulations, as well as analysis and optimization of water networks, ar e essential for development and implementation of feasible system closure s cenarios. Efficient in-plant and ex-plant contaminant extraction technologi es are required for reducing the concentration of white-water contaminants. New analysis techniques, such as pinch analysis, will have to be developed to facilitate selection of approaches for reduction of fresh water use. Im proved non-linear controllability techniques are needed for improving the d ynamic performance of integrated processes.