In this paper we present the results and implications of an optimization project carried out at the Domtar Espanola Mill. The project involved the implementation of an FT-NIR liquor analyzer installed in the recausticizing area for measurements of raw green liquor, clarified green liquor, #1 causticizier outlet, #4 causticizer outlet, weak wash, and final white liquor for complete liquor compositions. The implemented control strategy utilizes the liquor compositions to perform trim control of the clarified green liquor going into the slaker as well as the controlling the lime screw feeder for slaker and final Causticizing Efficiency control. Results from the trim control of the clarified green liquor showed that the mill was able to reduce the total titratable alkali variability by more than 50%. Using the CGL and causticizer liquor compositions for controlling the slaker, the mill saw a measureable decrease in carbonate deadload of 0.1 lb/ft3 and a 50% reduction in new lime usage during normal operations. The mill achieved sustained increase in recausticizing MSR, which has led to a production increase. The installation challenges and success along with these and other benefits will be presented and discussed.
展开▼
