Decreasing coal consumption and subsequently CO2 emissions at the mill
The projectâ€™s goal was to reduce steam consumption in deaerators by using heat from the digesters (otherwise wasted) to heat demineralised water that was then used in the mill processes. The project was an internal cost reduction initiative achieved through the increased efficiency of steam and power generation, and significantly reduced fossil fuel consumption at the Kwidzyn mill.
The concept behind this innovative thinking was not to direct the dirt left after one technological process to the next process, but instead to use it for power generation at the millâ€™s CHP unit. On top of the reduced cost from decreased coal consumption, the project achieved a remarkable environmental effect, notably reducing CO2, dust, SOx and NOx.
The biggest conceptual challenge was how to separate and then utilise condensates with mixed temperatures (difference of up to 30-35 degrees Celsius) and pressure (pressurised and atmospheric vessels). One of the first operational challenges arose from the very short time for implementation: four days during the annual shutdown to connect new installations to the existing set-up. The second was the optimisation of the new control system and the stabilisation of heat recovery.