Expert insights on use of enzymes as a driver of Pulp and Paper’s future

Buckman has a longstanding collaboration with Novozymes,  a world leader in biosolutions. This liaison underscores benefits of the use of enzymes in the pulp and paper industry. An interview with Greg DeLozier, senior staff scientist at Novozymes, offers updates – and myth-busting — on the state of enzymes in paper production.

Question #1: Use of enzymes in the tissue production process is well known, but paper-based packaging has been lacking on important insights needed to adapt it into the manufacturing process. What are the key characteristics of enzymes being used in paper-based packaging production?

This is a growing area and the trends have been very favorable in recent years. The enzymes that tend to be used in packaging applications are fiber modification enzymes, just like those in the tissue industry. This promotes better strength, use of less fiber and fewer chemicals to produce products. Certainly, there are likely to be slight differences between the enzymes in the packaging and tissue industries — based on specific PH, consistencies, types of fiber, temperature and retention time — but the enzymes are largely similar. Unique to packaging applications is that certain enzymes can be added to alleviate other issues, especially ones that involve recycled fiber. In this instance, deposits and small substances may absorb additives in an unfavorable way, so we have enzymes specifically designed to target those issues, allowing chemical usage to be more efficient. The more fiber is recycled, the more quality decreases and, because we are becoming so good at recycling fiber, you see materials accumulating in the recycled fiber stream, creating opportunities in deposit control for enzymes.

Question #2: Enzymes are known for helping with the bleaching process or deposit control in OCC. Are there other areas where you see significant results?

Enzymes have long been used to control certain deposits. They are used in specific ways: one is an enzyme that targets pitch and is introduced during mechanical refining or mechanical pulse; another is an enzyme that targets stickies that are associated with recycled fiber. Other enzymes deal indirectly or directly with biological deposits that may accumulate on the paper machine or in the final product. Such deposit control enzymes have been applied in this way for a long time, yet there is still opportunity for growth, especially given new deposit control enzymes that have recently been introduced into the market. Beyond deposit control, we see enzymes being used in the modification, upgrading fibers, allowing mills to use locally sourced or cheaper fibers in their operations. Bleach boosting is one of the oldest ways enzymes are used in pulp and paper mills. We also have starch modification for surface or internal applications.

Question #3: Many people working in the industry believe that enzymes are living beings and could intervene in the natural production of paper-based packaging. How do you address this?

All enzymes are protein and no different from some of the other applications of enzymes that are available. These are simply three-dimensional biological macro molecules of amino acids, so they have no ability to replicate and reproduce. They are there for a short time to do whatever they are meant to do for the fiber or for deposit, and then they degrade. They do not end up in the product. Enzymes can be differentiated from other technologies so that they do not become a part of the fiber of the substrate they are treating. They use natural components of that substrate, and they modify them and introduce new properties, using that substrate’s own components.

Question #4: How do you address the topic of enzymes performing too slowly or unpredictably in paper production tests?

Enzymes tend to be slower than some other chemistries. The impact of chemical additives is immediate and can be seen in the moment. Typically, enzymes applied in the proper way need to cycle up in the system. This may mean adding a very small amount based on the closure of the system or feedback within it. This approach is more economically sound than starting with high, unneeded doses. When enzymes are building up in the system, they are perceived as slow, yet they start showing results at the point in the process where they are meant to perform. That said, there are a number of spaces in pulp and paper production where enzymes can be applied to deliver the greatest benefit. Before recommending enzymes, we look to determine the proper point for them to be applied. We don’t design products that require process modification or changes. Enzymes should be able to adapt to and withstand the conditions within the time required to deliver the benefit. If slow, it may indicate that the correct application location was not found. Changes in process conditions will affect the performance of the enzymes as well. It is all about knowing the system and understanding whether something in the process could deactivate the enzymes. Another factor is the type of enzymes used. Mono-component enzymes can be controlled, since they only have one molecule, and they are predictable. That provides a small buffer against unpredictable reactions. Multi-component enzymes can be more unpredictable, in some cases, working in synergy, while in others, delivering different results, such as low degradation in the fiber. Knowing as much as possible before introducing enzymes is one way to deal with the unpredictable nature of the enzymes.

Question #5: How can enzymes help paper-based packaging producers, and what are the main benefits of using them in the production process?

One of the primary applications results in improvement of runnability of the furnishes being used. The more recycled fiber is used, the more treated the process needs to be. Other enzymes that act on the surface of the fiber and add new functionalities that interact with other fibers and other chemistries foster new strength-structure relationships. It promotes meeting strength requirements using less chemistry. Or it can modify the fiber in such a way that allows less use of virgin fiber and more recycled fiber. Benefits include improved efficiency and improved properties of the finished good.

Question #6: Today’s packaging producers are looking for more sustainable products and materials, including chemistry. Can enzymes help and, if so, how?

The enzyme production process is itself a carbon neutral process. Enzymes are produced using the same standard procedure as someone would use making a beer, so the enzyme itself is not a fossil fuel molecule; it’s produced naturally by organisms. Improving the runnability of the furnishes reduces the energy requirements in the drying section. In addition, enzymes create an opportunity to reduce the chemistries that are used, such as functional additives in paper production or the bleaching chemistries in pulp mills. Anything that the enzyme does to reduce energy input lowers CO₂ emissions and the carbon footprint. Anything that allows greater use of recycled fiber results in less carbon dioxide release than when using a virgin fiber. In almost every way, enzymes deliver a sustainable benefit.

Question #7: How do you see regulatory developments impacting choices for more sustainable materials, including chemistry? Do you believe enzymes would have an opportunity in this field?

Enzymes are being used in multiple industries where these regulatory decisions could affect them. In my opinion, the enzymatic solution can be an alternative solution under any regulatory requirement. It is relatively easy to defend the usage of enzymes, as long as they are being used safely. Since enzymes don’t become a part of a final product, they would not be as affected by regulatory issues as other chemical substances.

Question #8: Do you see enzymes having better results being used in virgin or recycled paper production? What advice would you give for both types of manufacturers?

Enzymes show very positive results in recycled paper applications — especially in the packaging segment — but also in printing paper, by offering low risks with efficient results. Deposit control is another area where enzymes are showing clear benefits, so we know that enzymes are being used in recycled fibers. In terms of virgin paper, bleaching and market pulp modifications, there are many applications being used. In general, enzymes are doing things to fiber that are not attainable from other chemical processes. These fibers acquire attributes that they wouldn’t have without applying the enzymes. The biggest challenge I see in the market is that people expect to drop enzymes into the system and then do everything as they always did. Education is key, and everyone should be comfortable with knowing what they can achieve, such as reducing refining energy or chemicals, making slight changes they would like to make anyway and that would be beneficial to them. Not every enzyme that is in the market is exactly the same and they should not be treated as such.

For information on Buckman’s enzymatic technologies for Pulp & Paper applications, please visit our webpage.