Paper Technology International 2024 - Journal - Page 85
PAPERTECHNOLOGYINTERNATIONAL
ramps up water
TToscotecreduction
in tissue making
Elisa-Bertolucci, Fiber System Engineering Manager, Toscotec
INTRODUCTION:
Water use in the industrial sector at large is one of the most important topics of debate; in particular, in paper production this natural
resource is an essential component for 昀椀bres transportation, equipment cleaning, lubrication, cooling and in the achievement of high tissue
quality.
Due to growing economic and environmental pressures, water saving strategies are one of the most important driving forces for
paper technology development. It is important to underline that pushing the tissue making process toward actual water reduction has
signi昀椀cant negative impacts on several technological operations.
Water reduction approaches are very complex and bring to a progressive closure of the process water loop, which leads to
accumulation of contaminants and may cause paper defects, deterioration of product quality and problems with tissue machine run-ability.
The degree of water loop closure is strictly correlated with the negative impact that may affect the paper process as shown by K.
Olejnil et al [1] and J. Boguniewicz-Zabłocka et al [2]. In this context, it is crucial to establish the right equilibrium between advantages and
disadvantages relevant to water consumption restrictions. The water consumption of today’s paper making processes varies between 5 and
20 m3/ton paper [1].
Figure 1: Water consumption at paper machine by major grade. Data from Fisher International for 2020.
ABSTRACT
Water is an essential ingredient in the tissue making
process and its reduction is a very sensitive topic. It is necessary
to 昀椀nd the right balance between water reduction advantages and
disadvantages.
Water reduction leads to the closure of the process water
circuit, which can affect the tissue making process. In this study, we
will illustrate state-of-the-art solutions to substantially reduce water
consumption ensuring an ef昀椀cient paper production.
In this 昀椀eld, great progress has been made in recent years,
but the increasing stress on fresh water availability and widespread
calls to reduce water usage have put water reduction strategies at
the forefront of technological development.
In this article, we analyse the best practices and most
advanced available technologies to reach a freshwater consumption
in the entire tissue making plant lower than 4 m3/ton paper.
This ambitious target can be reached by working on four
main areas:
•
Machine showers
•
Suction roll sealing technologies
•
Cooling utilities management
•
Stock preparation
In particular, water consumption for tissue paper mills that
work with virgin pulp is close to 5 m3/ton paper compared to mills
that operate with recycled 昀椀bres.
There are two main approaches to water consumption,
which can be combined to maximize water savings [3]:
•
Implementation of advanced water treatment processes
for wastewater recycling and re-use
•
Development of new technologies that reduce water
consumption.
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