Stabilising Water Demand to Sustain Production
Stabilising Water Demand to Sustain Production
75% Fewer Production Interruptions. 5% Lower Water Use.
A leading pulp mill faced recurring production cutbacks whenever its freshwater reservoir dropped below a critical level. Anssum stabilised the mill’s water system through Advanced Process Control (APC), refined local control strategies, and deep engagement with plant personnel. Water consumption reduced by 5%, production interruptions due to low reservoir levels reduced by 75%, and total effluent flow reduced by 1,000 m³/day, alongside significant process and quality gains.
Water Availability Had Become a Production Constraint
A leading pulp mill relied on a freshwater reservoir to sustain production. Whenever the reservoir dropped below a critical level, production had to be cut back to prevent complete water shortages.
Uncontrolled Demand Peaks Were Depleting Reservoir Reserves
At first glance, this seemed like an external supply limitation. However, Anssum’s investigation uncovered that the root cause lay within the mill’s own water usage patterns. Consumption was inconsistent and highly cyclical, with sharp peaks caused by various batch-based operations. Every time these peaks coincided, the demand on the water network surged, depleting reserves and forcing reactive responses. The instability propagated across the system, affecting the entire operation.
The challenge was therefore not just to reduce water use, but to fundamentally re-engineer how water was managed, stabilising consumption and restoring confidence in the system’s resilience.
A Three-Phase Roadmap to Stabilise, Improve and Enhance
Anssum developed a structured, three-phase roadmap to address the problem holistically:
- Stabilise water usage by smoothing out peaks and balancing demand.
- Improve efficiency to reduce total consumption.
- Enhance system performance to restore design-level operation.
Implementation Process
Phase 1: Stabilisation
The first step was to stabilise water flow to the factory, focusing on the main high-impact areas: thin liquor heat exchangers, flash tanks, gas scrubbers, internal water transfers, and coarse and fine dilution lines. These systems consumed large volumes of water in short, uncontrolled bursts. Water valves were manually opened to full capacity whenever batches allowed, often delivering more water than needed.
Anssum introduced Advanced Process Control (APC) and refined local control strategies so that water flow was no longer manually set but dynamically calculated based on process needs like gas pressure, liquor flow, and pulp throughput. This approach reduced unnecessary surges and made water consumption predictable and efficient.
Just as importantly, Anssum placed strong emphasis on operator involvement throughout the process. The team ensured that the mill’s operators fully understood the new control strategies, why changes were made, and how these would impact day-to-day operations. Feedback from operators was actively incorporated into tuning and logic design, making sure the end users were both comfortable using the new system and confident that it added genuine value to their operation.
The collaborative approach transformed an external intervention into a jointly owned success, ensuring the improvements were embraced, maintained, and sustained well into the future.
Lower Water Consumption, Greater Stability and Wider Process Gains
The results were immediate:
- Water consumption reduced by 5%.
- Production interruptions due to low reservoir levels reduced by 75%.
- Factory water flow stabilised, allowing continuous operation even under constrained water conditions.
Beyond water savings, the stabilisation efforts led to significant process and quality gains:
- 19% increase in digester liquor discharge to evaporators, boosting boiler fuel production.
- 1.4% increase in thin liquor Total Dissolved Solids (TDS), improving evaporation efficiency.
- 31% increase in gas flow to absorption tanks and complete elimination of gas scrubber emissions.
- 68% improvement in pulp consistency stability at the paper machine.
- 22% reduction in basis weight error, improving product quality and reducing waste.
- 1,000 m³/day reduction in total effluent flow.
Elimination of warm water tank overflows, conserving valuable process heat and water.
Key Takeaways
Technical Control and Operator Ownership Sustained the Improvement
The project’s success hinged not only on Anssum’s ability to identify, isolate, and address the root causes of instability, but also on the team’s deliberate efforts to ensure that operators understood, trusted, and embraced the new solutions.
By involving end users in every step, the implemented changes became part of daily routine rather than an external imposition, a crucial factor in sustaining the improvements over time.
This case stands as a clear example of how Anssum’s integrated approach of combining technical expertise, process insight, and human engagement drives sustainable operational improvement that endures long after implementation.
