I’d like to start with an environmental theme.

System closure in pulp and paper mills has been practiced in varying degrees over the past two decades. System closure means a reduction in the mill water use and the recycle of mill effluents. In a bleached kraft mill, the closure generally implies the partial or full recycle of the bleaching effluents. However, several steps have to be taken to prepare the mill for closure. Complete water, energy and process/non-process element balances are required to establish a base-case scenario. Process modelling can do this, and predict the effect of process changes before a mill trial is carried out. In preparing the mill for the recycle of bleaching effluent, water reduction and process optimization can provide tangible benefits in terms of water treatment cost, and fiber, energy and chemical savings even before the recycle is attempted.