The Future of Water for the Pulp and Paper Industry

this paper mill aeration basin is used as part of the wastewater treatment
This paper mill aeration basin is used as part of the wastewater treatment process so that the wastewater can be reused. PHOTO: SOLENIS

The statistics are sobering: around the world, water use has been increasing at more than double the rate of population growth, according to the UN. Industry (including pulp and paper) is responsible for 12 percent of global water withdrawals. UNICEF and the World Health Organization estimate that, by 2030, 1.6 billion people will lack safely managed drinking water services. The effects of climate change mean that, by 2040, almost a quarter of the world’s children will live in areas of extreme water stress.

Ceres, a nonprofit that works with influential capital market leaders to solve global sustainability challenges, including water scarcity, sums it up. “Global economic systems have long treated water as if it is infinite and of little value, leading to massive waste and misuse of the resource, imperiling ecosystems, human health, and long-term economic sustainability… Research shows that we’ll be unable to meet even 56 percent of global water demand by 2030 unless investors, companies, and governments urgently improve water stewardship.”

Water is more than just a critical component of the pulp, paper, and packaging we produce; it is essential to the health and safety of our environment, our communities, and the people who staff our mills and use our products. Protecting this resource is more than just good business; it is a clear responsibility to the future. Paper360° spoke to experts at three leading companies (see sidebar) that focus on helping our industry manage its water use.

P360°: When we talk about water for manufacturing, there are many components to “lower environmental impact”: for instance, water use and/or re-use; quality of influent/effluents; carbon-neutral concerns; and the impact on people and communities. Are some components more critical than others?

RICE & BARKER: While every mill situation is different, reduction in water use impacts the process in many ways. Deciding where to start can be challenging, but always begins with creating a detailed survey of a mill’s existing water usage. Some of the “lower impact” areas that can substantially reduce water use in a mill are:

  • Dissolved air flotation (DAF)/process water clarification enhancement — maximize returned process water for all dilution activities.
  • Using process water to replace fresh water for chemical additive injection/dilution (with proper injection equipment).
  • Cooling towers/utilities — increase in cycles of concentration, reduction in fresh water makeup.

All of these components are important, but priorities will vary site-to-site depending on location, region, and sustainability goals. Most mills have already taken steps to reduce water consumption. Now they must shift to recycle and reuse. These approaches may require more complex solutions and capital investment for equipment to prepare water for recycle/reuse.

In many cases, the water cost alone will not lead to the ROI required to move the project forward. Part of the effort will need to focus on the financial calculations and thinking about financial impacts including energy, chemical costs to treat influent/effluent, fines/surcharges, and impact on the community (such as odor or water contamination events). Building successful applications in smaller, lower risk water reuse efforts can build confidence to tackle and invest in larger projects in the future.

Water is a very local resource. What challenges does this create for mills seeking to control and improve water efficiency?

CALL, COBB, & ROPP: Local, state, or province regulations, as well as proximity to other natural resources and municipalities, create significant risks for pulp and paper mills. Given the interconnected nature of heavy industry and surface water systems, pulp and paper mills are a lightning rod for NGOs and local governments, even when contamination issues arise from other industries like agriculture or mining. Critical factors for pulp and paper mills to consider in the future will be 1) how to run increasingly closed loop systems and 2) superior effluent discharge monitoring capability.

However, these needs are at odds with influent quality requirements. Pulp and paper mills will use lower quality influent, running water through their system multiple times, while still being accountable for higher quality effluent leaving the mill. The dynamic will raise requirements for all parts of mill operations.

RICE & BARKER: Mill location and main water source greatly impact costs for a mill considering water use reduction. Large, integrated mills drawing from large rivers and lakes often have a “low” cost for incoming water. Conversely, recycle paper mills located in metropolitan cities will frequently use far more expensive municipal “city” water for their main incoming water source. As may be expected, high-cost incoming water mills have spent more effort on conserving and recycling water in their processes. These can be good examples of how to reduce water use at other sites.

How are digital technologies helping mills manage water issues?

LEDLIE: Instrumentation, monitoring and control solutions, and advanced analytics are all digital technologies that help manage water issues in pulp and paper mills. They do so by providing real-time information about influent, process, and effluent waters; by facilitating communication and problem solving; and by enabling faster, more insightful analysis of water and process data.

Mills use instrumentation to measure parameters such as pH or oxygen reduction potential in various water streams. These measurements inform operators about key operating or discharge parameters and enable alarms for out-of-control situations. Real-time, cloud-based monitoring and control solutions facilitate problem-solving because people in different locations can view the same data at the same time, thereby communicating and collaborating more effectively. The use of advanced analytics, such as machine learning and artificial intelligence, capitalizes on the large quantity of data streaming to the cloud by allowing for faster and more insightful analysis of that data to optimize the process through real-time predictions.

Water systems in paper mills are interconnected and complex; to maximize water efficiency and achieve consistent results over time, all of these technologies must be employed.

RICE & BARKER: Digital modeling of a paper mill’s water profile is one of the best methods for understanding how changes in water use will impact key parameters that affect production. By digitally modeling the process, different scenarios can be represented, indicating how pH, hardness, conductivity, and other key performance parameters will be impacted. This is an excellent way to envision the steps a mill can take toward greater water closure as different fresh water sources are replaced with recycled sources.

CALL, COBB, & ROPP: Digital innovation enhances water treatment processes on multiple fronts. At a high level, there are three main types of digital solutions: monitoring, control, and prediction. Improved monitoring solutions have been an area of innovation for years and will continue to improve. Reliable and accurate data collection in the field is the basis for realizing a digital future for water treatment processes with robust control strategies and predictive analytics.

Reliable data collection allows mills to build robust controls for automating water treatment processes. This flow of information to the cloud is fueling major growth in predictive analytics via Industry 4.0. As more and more systems are integrated across multiple sites, we will be able to significantly improve our ability to identify and catch problems before they occur — whether through machine learning or human support.

Additionally, we see augmented reality and improved cloud connectivity enabling improved support from subject matter experts all over the world to help solve site-related issues. Industry experts connecting through a portal to work with their peers at the site without physically being present will be a key growth area and will improve the flow of information across an organization.

headbox after process water treatment

Headbox after process water treatment. Monitoring and treating influent can reduce freshwater consumption and increase runnability. PHOTO: BUCKMAN

What are the main drivers of global water scarcity? What role or responsibility does the pulp and paper industry have in helping address this crisis?

HAYDEN: Water scarcity occurs when the available amount of potable and unpolluted water is not adequate to meet the demand of industry, population, and agriculture. Waste or overuse of fresh water and water pollution are the main drivers of global water scarcity.

To help address and alleviate this global water crisis, we need to reduce our demand by using our limited fresh water resources more efficiently, avoid exceeding the water replenishment threshold, and return balance to the regions that have already exceeded this threshold. For our water resources to be sustainable long-term, we must reduce usage to conserve fresh water, and we must continue to find new ways to reclaim process water and wastewater.

CALL, COBB, & ROPP: While the global supply of water is constant, the use and replenishment of local water supplies is not necessarily constant or even reliable. In some cases, recharge of reservoirs and aquifers operates on a years- or decades-long cycle, while the growing demands for withdrawal cannot wait.

Crops and livestock must be watered daily, and they cannot accommodate the long cycles that are slow to refill wells and lakes. Human migration and higher urban populations increase the usage intensity of local water watersheds and other storage. Intensity of land use — including deforestation and plant cover changes, soil erosion, river diversions, and climate change — have altered the patterns of precipitation and evaporation. Paper industry-driven sustainable forestry initiatives maintain stable landforms and watersheds where water is stocked for use at sustainable rates.

Every water system relies on mechanical components such as pumps, valves, filters, meters, etc. Are some more important than others?

RICE & BARKER: Many mills think water reuse is too costly, complicated, and prohibitive; they neglect to implement smaller steps in the right direction using tried and true technologies. Not to sound “old school,” but filters and water clarification equipment are often underused in paper mills. DAF clarifiers, side stream filtering for partial removal of contaminants, and simple settling clarifiers can offer macro benefits to process water handling and re-use. It is not uncommon to find older equipment of this nature having fallen into disrepair or even bypassed because of mechanical deterioration.

Relatively small investments in mechanical, operational, and chemical performance of these assets can result in huge water savings opportunities. With the economics driving toward more water closure, these tried-and-true processes are still extremely useful and can be modeled to prove their value in a mill situation.

What is one important thing you’d like your pulp and paper mill customers to understand about global water scarcity/water resource sustainability?

CALL, COBB, & ROPP: With corporate and industry initiatives, paper manufacturers can offer organization and technology resources to recognize and predict patterns of water abundance and scarcity, and to help educate populations and governments to adopt a strategic mindset about where water will come from in the coming months and years.

Addressing water challenges is a long and challenging process. Taking proactive steps today can pay significant dividends in the future.

RICE & BARKER: Collaboration is critical. As with many issues we want to tackle in our industry, we can learn from each other about best practices. There are multiple mills running today as Zero Liquid Discharge (ZLD) sites, bringing in fresh water only to replace what is evaporated from the process. While it can seem like a daunting process, it is like most other challenges we face: take one step, measure the impact, adjust to the new conditions…and then take the next step. I have always loved the proverbial question: “How do you eat an elephant?” The answer: “One bite at a time!”

HAYDEN: Water is essential to life. Balancing fresh water consumption with fresh water replenishment rates is critical to the sustainability of our species, not just our industry. In our “ideal future,” all pulp and paper mills would be 100 percent closed. Achieving that goal, while extremely challenging and often expensive, would help reduce water scarcity and improve the sustainability of our fresh water resources.

Water scarcity already affects every continent. For our sake and for the sake of future generations, we all must work together, now, to find and implement the best solutions to effectively reduce fresh water consumption and reclaim water when possible.

Industry professionals sharing knowledge for this article are:

  • Fred Call, paper technologies water treatment COE applications engineer, Buckman
  • Todd Cobb, global market manager, Buckman
  • Adam Ropp, regional digital manager, Buckman
  • Bruce Barker, technical consulting team lead at Nalco Water, An Ecolab Company
  • Laura Rice, corporate scientist, water anchor RD&E, Nalco Water, An Ecolab Company
  • Tom Hayden, global marketing director, industrial water treatment for pulp and paper, Solenis LLC
  • Andrew Ledlie, global director of digital solutions, Solenis LLC

Some Top Tech

We asked our participants to briefly share their company’s most innovative or impactful solution for improving a customer’s water-related environmental performance. Here are their picks:

SOLENIS: The ClearPoint℠ biofilm detection and control program uses advanced chlorine stabilizer chemistry to produce a patented, in situ, stabilized, active chlorine solution that effectively controls both planktonic microorganisms and biofilm. The chemistry is used in combination with the OnGuard™ 3B analyzer, which provides early detection and accurate measurement of biofilm growth in industrial water systems. ClearPoint improves our customers’ water-related environmental performance by helping papermakers use their fresh water more efficiently, thereby conserving water. The program also reduces corrosion rates, halogenated organics, and operating costs.

BUCKMAN: The Ackumen™ technology platform and associated applications provide the next generation of smart digital solutions for multiple key processes and materials such as cooling towers and biocides.

NALCO WATER: One of the most valuable things any mill can do is digitally model its water system, allowing for war-gaming different scenarios for achieving better results. Nalco Water offers onsite audits focused on building system models for developing water savings opportunities. Also, our PARETO™ injection systems are designed to make the best use of process water for dilution of chemical additives at the site of injection, and we have many case studies for this technology having resulted in millions of gallons of fresh water savings, as well as chemical efficiency savings.

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