Featured piece written by industry leader, Andrew Hall, Allnorth Project Development Manager
Water moves everything in pulp and paper operations.
It carries fibre, chemicals, dissolved solids, and energy through nearly every stage of production, and it is one of the largest drivers of energy demand across the mill. Every tonne that is pumped, treated, heated, recirculated, and discharged adds load across multiple systems.
After more than 35 years working across pulp and paper operations, capital projects, and mill optimization globally, I have consistently seen one overlooked reality: water systems and energy systems are not separate and should be viewed as one interconnected system.
How Water and Energy Systems Work Together
Water is the lifeblood of any pulp or paper mill. It is both a process and a service fluid and is used for both heating and for cooling. What makes water circuits in modern mills so complex, is that at some stage during its journey through the mill, the same physical unit of water can fulfill all these functions. And to keep things interesting, it sometimes serves multiple functions at the same time.
Water and energy are therefore linked in a very tangible way throughout a pulp and paper mill. Since water is used to transport and store energy, it is not possible to separate management of the mill water balance from the overall energy balance. For this reason, any mill-wide energy saving initiative must consider the impact of water use on energy consumption.
Some items are obvious:
- Hot water overflowing to sewer represents an obvious loss of heat energy.
- Unnecessary cold-water make-up requires external heating (usually steam) to bring it to process temperature.
- Reconfiguring hot and warm water tank pumping systems to preferentially direct water with different energy values to the most appropriate services.
- Redirecting recovered water streams for uses that best match their energy values.
- Tempering heat exchanger feed streams to build in flexibility to generate high value hot water streams under variable process conditions.
- Establishing clear baselines
- Quantifying meaningful deviations
- Identifying the changes that matter most
- Prioritizing based on a tangible cost-benefit analysis
What is perhaps less obvious is the impact of the “quality” of energy stored in water. A small volume of very hot water has considerable value as an energy store. The same amount of energy stored in a large volume of tepid water is a disposal problem. This concept is also critical when considering electrical energy demands. The power consumption for pumping water around a pulp and paper mill is considerable. This cost is a direct function of volumes pumped, so it is more energy (and cost) efficient to move smaller volume, high-quality water streams, than larger streams with comparatively low value.
The art of designing a modern water management system is to deliver as much stored high-quality energy as possible, while simultaneously satisfying all cooling services and process water demands. This requires a system with the flexibility to manage the mass and energy balances as independently as possible.
The Real Opportunity Is Not Where Most Look
Water efficiency is often approached through capital investment. While equipment upgrades, and modern technologies are important, they are not always where improvement efforts should begin. Many North American mills were designed and built when water and energy were cheap, and annual sustainability reports were unheard of. It is not always practical or cost-effective to retrofit these older mills with the technologies found in modern, benchmark facilities, but that should not prevent progress.
The most effective approach is to apply modern design thinking in targeted ways to achieve incremental gains that begin to align existing mill systems with how newer mills are designed to operate.
In many mills, the most immediate opportunities already exist within current systems and can be implemented with minimal disruption and little to no capital. From my experience, there are many projects with modest investments and quick paybacks, that are simply not being prioritized and implemented. Examples of these could include:
In practice, strong results often come from better aligning pumping and heat transfer with actual demands, improving control strategies to consider stored energy as well as inventory requirements, and recovering heat from water and effluent before it is discharged.
Why Water and Energy Improvements Stall
Many initiatives focus on individual improvements without fully accounting for system interaction. Progress is made, but not always at the scale expected. Improvements in one area often shift load somewhere else. Changes in flow are made without corresponding control adjustments, and upgrades move forward without fully considering upstream and downstream impacts. The result is incremental improvement, but not system-level gains.
If water or energy use has increased over time, if processes require frequent operator intervention, or if performance has plateaued despite targeted improvements within individual systems, these are often signs of system-level inefficiencies.
In most facilities, the challenge is not a lack of opportunities. It is the ability to identify, prioritize, fund, and act on those opportunities in a structured way. The constraint is not necessarily awareness, but rather the inability of mill teams to dedicate time to such initiatives, while remaining focused on the day-to-day activities needed to keep the mill in production.
From Data to Decisions
Most mills already have the data they need. Flows, levels, pressures, and energy use are being tracked every day. The opportunity lies in connecting that data to action:
When data supports decision-making, it becomes a driver of continuous improvement. With data visibility, operating teams can make more informed decisions. They can understand how systems interact, identify real constraints, and prioritize improvements based on impact rather than assumption. This approach requires coordination across mill operations, process engineering, maintenance, technical, and environmental functions. When disciplines are aligned, and objectives and accountability are clear from the outset, it becomes much easier to move from analysis to execution.
Taking this coordinated approach to developing a structured program of practical, quick-win improvements does more than reduce water use or steam demand. It builds momentum and demonstrates that meaningful change can be implemented without disrupting production, while also improving visibility of overall system performance.
Closing the Loop
Water conservation in pulp and paper mills is a key aspect of any energy saving initiative. The most impactful gains come from understanding how complex systems interact and acting on that insight. Opportunities already exist in most mills – maximizing the advantage comes from viewing these mill-wide systems holistically and implementing the right improvements with confidence.
Success depends on designing with implementation in mind. It is not enough for a solution to work conceptually; it needs to perform reliably in a live operating environment. This requires practical experience and a clear understanding of how modern mills operate. Having worked across both operations and project delivery, I have seen that the most successful improvements are grounded in real constraints, aligned with how the mill runs, and are implemented in a way that minimizes the need for operator intervention.
Where to Start
For many operations, the challenge is not identifying opportunities, it is knowing where to focus and how to implement changes without disrupting production. An integrated approach brings the right disciplines together early, helping teams focus on the highest-impact opportunities and act with confidence.
At Allnorth, the focus is on analysing relevant data to gain a deep understanding of mill operating systems and then translating that clarity into practical improvements that fit the operation and deliver measurable results with minimal disruption.
Turn operational insights into measurable results. Explore how leading pulp and paper mills are using integrated analysis and cross-disciplinary expertise to optimize performance and drive sustainable improvements. Download the white paper.