The “zero” goal for water consumption is ambitious and perhaps utopian, and the paper industry has already reached its current technological limit. It can be learned, however, to change the approach to water management, evaluating the myriad aspects that can then, collectively, make a difference. A shift that needs to be made now, not least in view of climate change that is making this increasingly scarce and valuable commodity
Indispensable to life and crucial to survival, water is a precious resource that, for some manufacturing sectors, is essential to their production and to the quality of what they produce. Papermaking is one such sector.
However, water management is a complex issue, much more than we think. First and foremost, it involves a number of aspects and actors that are involved at various levels, and that together affect the cost, supply and mode of use of this essential commodity. Eduardo De Almeida, manager of Afry a consulting firm that also works in the paper industry, spoke about this at the Miac Paper&Board 2023 congress.
The overlooked importance of water
The warming temperatures, climate change and drought that have characterized the passing of the seasons for some time now have opened up the front of the importance of preserving and using water efficiently and consciously.
An issue that has perhaps been little considered, at least in Europe, where it has never been a priority until now, but one that current changes force us to reconsider. The importance of preserving this precious resource has also been overlooked because it has been considered of little economic relevance.
“In the paper industry, on the other hand, water management and water conservation are a priority,” says De Almeida, “and are at the top of the priority list.” According to Cepi data, as of 2021, sources of fresh water withdrawal by paper mills indicated that 87.3 percent is surface water, 12 percent is groundwater, and 0.8 percent is municipal networks. Over the years, the paper industry has made enormous strides to reduce its water needs, with some outstanding results, but unfortunately it is still not enough. The goal for companies is to get as close to zero fresh water consumption as possible.
“There is a lot of talk about sustainability, it is an oft-used term, but we have forgotten what it means, which is that we have to take certain actions in order to survive.” In this view, water management comes into its own. Several factors come into play to influence it. “First, we have legislation: companies that do not comply with legal regulations cannot operate. Another element is the risk of supply,” in different parts of the world, especially during the summer, the level of watercourses undergoes considerable variability, a situation that creates quite a few difficulties for industrial production, especially that of the sector, “water is part of the paper production process and the quality of products also depends on the quality of water.” Another factor incidental to water management and one of the important points of the sustainability issue is public opinion capable of creating pressure in legislative choices which then, in turn, determine the actions of companies.
Then there is the issue of cost, which is a crucial driver and related to the risk aspect of supply. “So far there have been no major concerns,” De Almeida points out, “but climate change is also driving big changes in terms of water availability and Italy is among the top countries at risk of water scarcity. There is also a big variation in supply prices in Europe, which shows how susceptible this is to legislation and also gives us an idea of the risk that companies are exposed to. Legislation can change abruptly and fees can increase at any time, all of which results in an additional element of risk.” And that’s not all, when we talk about the price of water we consider the water entering the paper mill but then to this we add other costs related to energy to run the pumps, for heating, those of the analyses that are done inside the laboratory, costs for chemicals used in the process and wastewater treatment plants. “A whole series of other cost items that go into precisely the cost of water, which then becomes much higher.”
Legislative News
Returning to the regulatory issue, De Almeida points out that alongside the scarcity of the water resource, the level of technology also contributes to shaping legislation, and together they then end up affecting the entire industry. “There are some changes that have been proposed for the water framework legislation” and that it is important for papermakers to monitor carefully. The reference is to proposal 2022/0344(COD) of October 27, 2022 to amend Directive 2000/60/EC. “In particular, there is a lot of talk there about restrictions on PFAS substances, with new limits on their presence; then there is talk about recycling and the quality of microplastics, estrogen monitoring, and additional digital controls. A number of elements, then, that are part of the proposals and will be discussed.”
All of this will also have an effect on papermakers, the management of water in their production cycle, their end product, recycling, laboratory activities, and even the chemicals and raw materials that are used by the industry. Therefore, it is important for papermakers to keep an eye on these proposals that have been formulated at the European level and that, once approved, will then have to be implemented in the various national and local legislations. “We need to be aware and try to understand the potential changes at the legislative level,” De Almeida continues, “and be ready, because they can also be implemented very quickly.”
Undoubtedly, he adds, “the less water you consume, the less you are exposed to all the pressures mentioned. So it is necessary to try to find a balance: we have water consumption on the one hand, the management of the whole plant on the other, and there is always also the question of cost. We need to find the optimal balance point.”
The optimal balance
When analyzing the data of water consumption in the paper industry over the past decades, the strides made by the paper industry in terms of greater efficiency in consuming the water resource are immediately apparent. Companies in the sector have always invested in technology that would allow them to recycle water within their process, closing the loop as much as possible. According to Assocarta data, while in the late 1970s an average of 100 cubic meters of water was needed to produce one ton of paper, today we are talking about 26. A figure that, in recent years, has now stabilized, proving that we have now reached a technological limit below which, at least at present, it is difficult to go.
Interventions to reduce fresh water input and thus partially close the water cycle involve several aspects. Opportunities to do so, by progressively reducing the amount of effluent input, already exist and consist of interventions acting on several fronts. These are often small steps, but each of them brings a benefit in terms of recovery of circulating water. From reducing dispersion by evaporation to recovering heat by harnessing hot steam for other needs in the production cycle, for example, using the heat available from hoods to dry sludge; to recycling water after effluent treatment.
Adding up all these possible steps-which companies in the industry have often already taken-can lead to a minimum threshold of process input and thus fresh water consumption. Finally, the costs of the entire system and the impacts that water treatment has on the environment must also be considered. According to statistics formulated by Cepi on 2021 data, it appears that about 90 percent of the water extracted to produce paper and paperboard was returned to the source after treatment. This requires compliance with strict legal limits. To date, for example, the pollutants in paper mill wastewater, says Assocarta, are now essentially of biological or natural origin, namely cellulose, starches and inert mineral fillers-for example, calcium carbonate. Over the years, the average emission values of COD (Figure 4) and suspended solids (Figure 5) have also been reduced as much as possible.
Small steps
It will be difficult to get below the quotas of water recovery and, consequently, fresh water consumption achieved so far, De Almeida points out, but the results are already very interesting (Figure 6). Undoubtedly this is a process of improvement that paper mills need to make gradually but steadily. “The first fundamental step is, as mentioned above, the importance of knowing the cost of water at the moment at the point of use. Then we need to understand and stay up-to-date on what the risks of water supply are at the local level, because that is where the decisions of the authorities have an impact. We need to be prepared for changes in legislation.” De Almeida points out in particular how important it is to pay attention to what will happen as a result of proposal 2022/0344(COD) to amend the Water Framework Directive. In addition, Afry’s manager continues, “companies must have a plan that involves different scenarios, a program to arrive at a reduction in consumption, and one that is suited to their situation. It is essential to have an energy and management system, and above all it is important to have a water management system with specific performance indicators (KPIs) and references against local conditions.” He concludes by reminding that “when we talk about reducing water consumption, we are not talking about a process that involves big changes, rather many small changes are needed.”