Turning the page to profitability - Paper Technology International 2023 - Paper Technology International 2023 - Flipbook - Page 105

Turning the page to profitability - Paper Technology International 2023

PAPERTECHNOLOGYINTERNATIONAL Turning the page to profitability - Paper Technology International 2023
In humans, plants, and animals, they play a key role in
a wide variety of life-sustaining functions, including metabolic
processes like respiration and digestion. In industry, enzymes
have been used for centuries as catalysts in a broad range of
applications. Because they are highly selective as to their function,
they produce fewer side reactions, require fewer reprocessing
and purification operations, and produce less pollution and
effluents, enzymes have become cost-effective, biodegradable,
environmentally friendly solution for synthetic processes at an
industrial scale.
Every type of enzyme is a unique chain of amino acids
that has evolved to perform a single catalytic activity on a
specific substrate — sort of a natural lock and key mechanism.
The enzyme’s unique three-dimensional structure seeks out a
substrate molecule with a complimentary geometric shape. During
the enzymatic reaction, the substrate binds to the active site of
the enzyme, converted to a reaction product, and released. Most
enzymatic reaction rates are millions of times faster than those
of chemical or metal catalyzed reactions. And, like any catalyst,
enzymes aren’t consumed by the reactions. The enzymes remain
intact after the reaction and moves on to react with more substrate
molecules. That´s why only a very small amount of enzyme is
needed to produce the desired result and deliver value.
Thanks to modern technology, it is now possible to develop
robust enzymes to fit the needs of specific industries like household
care, food and beverages, agriculture, animal production, biofuels,
and textiles. And it stands to reason that this natural approach to
adding value should apply to an industry that is as deeply rooted in
nature as pulp and paper.
An enzymatic approach to paper mill optimization
Using enzymes in pulp and paper mills isn’t new. They have
been recognized as having great potential to save on chemical and
energy use and add value to a number of pulp and paper products.
Improvements in production efficiency with enzymes are now used
on an industrial scale in the industry, as additional ground-breaking
biotechnology research continues with the aim of replacing different
conventional pulp and paper processes with more sustainable and
efficient solutions.
Historically, multi - enzyme “cocktails” have been tested
and used in pulp and paper for decades with varying results. These
applications were explored and tested before the technology was
developed to make well-defined, single-enzyme products. Although
they can produce measurable benefits in some instances, this
shotgun approach has potential drawbacks. The most abundant
and important component of papermaking fibers is cellulose. The
goal of enzymatic fiber modification using cellulolytic enzymes, or
cellulases, is to add value to the fibers while preserving fiber yield.
Cellulases, are produced by fungi, protozoans, and certain
bacteria. In nature, they aid in the decomposition of plant matter.
Different types of cellulases can break down cellulose molecules
into simple sugars (monosaccharides) and other sugar molecules in
a concerted manner. This saccharification process is a critical step
in the production of biofuels. Cellulases can also be used to modify
fiber in the pulp and papermaking process.
However , the use of multi-enzyme cocktails to produce
this degree of action on cellulose in papermaking fiber can produce
undesirable results. A problem that only gets worse with crude
enzymes that are not refined to a sufficient level to meet pulp
and paper needs. What is required is a level of technology that
is designed and standardized for the production of high-quality
cellulase-based products.
The use of cellulases to modify paper fiber requires the use
of carefully selected molecules that add value to the fiber while also
preserving its integrity. Multi-component cellulolytic enzymes are
more difficult to control and can do both harm and good to the fibers.
Additionally, when using multiple enzymes, there’s often no way to
fully ensure that enzymes aren’t present in the final product.
The alternative is a more targeted, “rifle” approach based
on mono-component enzyme products. Modern biotechnology
allows the production of single-enzyme products that produce a
more controlled modification of fibers and other components in
papermaking.
Targeted enzymatic treatment can deliver potential benefits
across the entire pulp and paper process, with minimal risk of the
adverse effects sometimes experienced with multi-component
treatments. These include improvements to deinking, bleach
boosting, deposit control, and starch modification. But some of
the most pronounced benefits in terms of boosting production and
getting the most paper and board possible from every tree come
from using enzymes in fiber modification.
Figure 2a & 2b: before and after - “FiberCare® modifies the fiber surface and improves pulp fibrillation for more contact points and
better bonding”.
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