Case Study: Ultrafiltration Reduces Boiler Blowdown At India's Largest Paperboard Mill

The Paperboards & Specialty Papers Division (PSPD) of ITC Ltd. operates India's largest paperboard manufacturing plant. The plant produces packaging and graphic paperboards, specialty boards including boards with polycoated barriers, and paper for cigarette tissue, fine printing, and decoration.

The facility has earned a reputation for technological innovation and environmental stewardship. The ISO-14001 certified mill is 98 percent power self-sufficient through cogeneration, and it recently commissioned India's only elemental chlorine-free pulp mill.

The plant generates 250 tonnes per hour of high-pressure steam at 62 bars to satisfy the mill's power and process requirements. Engineers at the plant found that the silica impurities in the boiler water were high, necessitating frequent blowdown operations that consumed large volumes of water and wasted heat energy. Further investigation determined that the source of the problem was colloidal silica in the form of fine mud in the boiler feed water.