How to Reduce Water Usage in the Pulp and Paper Industry
Without water—and lots of it—manufacturing pulp and paper would be all but impossible. Water usage in the pulp and paper industry is needed in almost every part of the process, whether the facility is digesting wood chips, making fiber slurries, or washing the machinery and rollers.
Despite there being great progress over the years, increasing stress on fresh-water availability and greater calls to reduce water usage further, paper mills have been under more and more pressure to adapt their processes and ensure they’re efficient enough to reduce their waste. An added pressure is attempting to achieve all this while also being conservative on cost, which can make the paper mill’s water-reduction strategy all the more challenging. Pulling fresh water from and disposing wastewater to local sources like lakes and rivers and publicly owned treatment works (or POTWs) can be extremely expensive; resources are increasingly limited, and if you are able to utilize these sources, chances are you’ll be paying exorbitant fees. Mandated wastewater disposal regulations are increasingly stringent, too, and if your facility isn’t able to treat your wastewater to federal and local standards, your facility will incur more fees and possibly even lose its ability to utilize that source.
Because of all these reasons and more, pulp and paper companies are adjusting their goals to be more environmentally conscious, to be better stewards of the available natural resources that are often shared with their local communities, and ensure their businesses are able to adapt to an everchanging landscape.
If you’re researching ways to reduce your pulp and paper facility’s water usage volume, here are some things your facility can implement in its day-to-day operations.
Update or regularly maintain your equipment
One of the important ways industrial facilities in the pulp and paper industry can reduce their water usage is by ensuring water-centric machinery is in the best possible shape. This might mean you need to:
- regularly check and replace your spray nozzles; as they’re used, the holes can increase in size, allowing more water to pass through with less pressure
- ensure aging infrastructure is replaced; as a facility’s pipelines, pumps, and water treatment systems age, their ability to process and hold water efficiently can cause a high level of water loss, and, in certain cases, an overuse of energy
- make boiler maintenance and feed water treatment a priority; ensuring boiler water is properly treated will not only protect your facility’s equipment, but by replacing your older, aging technologies with newer, more efficient ones (like ion exchange) will help your facility reduce its water-usage footprint
As always, and with most industrial facilities, replacing and maintaining equipment can seem costly upfront, but you need to consider how it saves your facility over time. Many of the newer technologies are much more efficient and designed with water efficiency in mind, so make sure to analyze how much the new equipment and machinery might cost compared to the long-term costs and savings. Also keep in mind that the volume of water your facility needs and the way it is used and treated depends on the type of paper being made and what it’s for, as the production processes can vary greatly from product to product—so when you’re looking for water-maintenance technologies and services, be sure to have this information available. The best solutions will be customized to meet your specific production needs and treatment parameters.
Cost-effective waste reduction and recycling
As mentioned prior in this article, connecting to water sources for both drawing water and releasing it back into the environment are becoming more costly and the restrictions more stringent. One way many paper-making facilities are curbing this cost is by finding ways to recycle the water used in the paper-making process. This can be particularly useful in drought-prone areas.
The exact treatment plan will vary significantly depending upon the contaminants present and how pure it needs to be for what you’re reusing it for. (Does it need to be extremely pure for boiler feed? Not as pure for washing and rinsing machinery?)
For some industrial applications, it is also possible to conserve water by reusing it for two or more cycles without pretreatment. Reusing wash or process water may require moderate upfront investment in tanks and pumps, but typically provides a return on investment within the first year after implementation. Many facilities use contact cooling water that is dumped directly to drain. This water can be captured and pumped back into the facility for alternate uses.
Common technologies used in a wastewater treatment train aimed at recycling the water for reuse can include:
- filtration; consisting of media and/or membrane filtration units, these technologies are used to remove particulate solids from waste streams
- biological treatment; comprises a variety of technologies used to break down and/or remove biodegradable solids
- ion exchange and RO; includes a variety of resin technologies used to selectively remove dissolved ionic contaminants
- distillation; a heat-driven separation process used to separate liquid components of a mixture, often deployed for recovery of industrial solvents
Since industrial waste streams typically contain a variety of contaminants, wastewater treatment trains typically combine a few of these technologies to ensure that the treated stream is suitable for intended applications or discharge. Some systems, such as zero liquid discharge (ZLD), are capable of minimizing water waste right down to nothing at all.
Auditing water use
An important jumping off point is to have your facility evaluated for its current water use. Water use audits are important for understanding how water is used at your facility so that you can clearly identify opportunities for reducing consumption. While some facilities conduct water use audits internally, hiring a water treatment professional can provide deeper insight into your water usage due to greater access to industrial benchmarking data and knowledge of appropriate treatment technologies. Additionally, since water-use audits quantify water usage and waste, they provide valuable data that can be leveraged for initiatives aimed at conserving water through behavioral or cultural changes.
Start small and aim big
No papermaking facility is going to reduce its water consumption overnight. The process takes a lot of planning and consideration to make sure the solution implemented return the level of savings appropriate for the facility. Take the process one step at a time. Have the water assessment done, make a list of aging machinery, see which materials your facility can recycle and reuse, think of ways your papermaking process can be adapted, seek help and insight from similar businesses. With little change over time, your facility can be on its way to being much more efficient with its water sourcing and usage.
Can SAMCO help?
SAMCO has over 40 years’ experience custom-designing and manufacturing efficient water treatment systems for a range of industries and applications, so please feel free to reach out to us with your questions.
For more information or to get in touch, contact us here to set up a consultation with an engineer or request a quote. We can walk you through options for industrial water conservation solutions that fit your needs and maximize your return on investment.
Head on over to our blog to learn more about available water treatment technologies to help reduce industrial water consumption and prepare for water shortages. Some articles that might be of specific interest to you include: