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Publications (4 of 4) Show all publications
De San Pio, I., Simons, A. & Delgado, L. F. (2022). Process Water Management for Sustainable Papermaking. In: : . Paper presented at TAPPICon 2022. TAPPI Press
Open this publication in new window or tab >>Process Water Management for Sustainable Papermaking
2022 (English)Conference paper, Published paper (Refereed)
Abstract [en]

Some of the challenges in papermaking have been the same for many years, however the demands from the market are increasing continuously and, together with them, the challenges for the paper mills. We consider it is the time to put a lot of efforts together to help papermaking industry to comply with these new demands on a cost-effective way. When it comes to the wet-end chemistry and stock preparation this is a clear and actual challenge. Many developments have been done in developing green chemicals with higher efficiency, machine suppliers are improving the efficiency of each unit, fiber recovery and water cleaning technologies are also under continuous improvement, but the degree of implementation of those advances is still limited. From our perspective, a mindset change is needed, where all those developments are combined to improve the product properties and the process efficiency. Process waters have a very important role to play in that, and in this presentation, we will demonstrate the link and importance that keeping the process water components under control can give to the process. Those improvements were evaluated at lab scale, demonstrated at pilot scale and then implemented at mill level. We will show how the performance of the process chemicals is affected by the process water components, and the impact on the product quality. We will also describe the methods used to understand and evaluate those impacts and describe in a full-scale test how improving the process waters lead to energy savings and the possibility to improve the product performance. The designed methodology can be of use for: - Chemical suppliers, that need to evaluate and demonstrate the performance on challenging processes, such as closed water loop mills. - Companies looking to save water and energy, identifying the costs related to their actual water management and therefore the benefits to implement the right technologies. - Water cleaning technology suppliers that are nowadays not implemented in paper mills, that would be able to demonstrate the removal of the right contaminants and the potential savings that this technology can give to the specific mill. - Paper mills with challenges due to changes in their incoming water quality, or when there are increasing demands from the market that require adaptation of the process chemistry, unlocking possibilities for further development. 

Place, publisher, year, edition, pages
TAPPI Press, 2022
Keywords
Commerce; Cost Effectiveness; Energy Conservation; Paper Products; Water Management; Water Quality; Commerce; Cost effectiveness; Energy conservation; Paper products; Papermaking machinery; Water management; Water quality; Cleaning technology; Cost effective; Paper mill; Papermaking industry; Performance; Process water; Stock-preparation; Water cleaning; Waters managements; Wet-end chemistry; Papermaking
National Category
Paper, Pulp and Fiber Technology
Identifiers
urn:nbn:se:ri:diva-68118 (URN)2-s2.0-85175649631 (Scopus ID)
Conference
TAPPICon 2022
Available from: 2023-12-04 Created: 2023-12-04 Last updated: 2023-12-06Bibliographically approved
Krochak, P., Johansson, K. & De San Pio, I. (2021). The effect of contact time between CPAM and colloidal silica on the flocculation behavior in the approach flow. TAPPI Journal, 20(1), 39-47
Open this publication in new window or tab >>The effect of contact time between CPAM and colloidal silica on the flocculation behavior in the approach flow
2021 (English)In: TAPPI Journal, ISSN 0734-1415, Vol. 20, no 1, p. 39-47Article in journal (Refereed) Published
Abstract [en]

Multicomponent wet-end systems have become increasingly common in papermaking, with the objective of improving the retention-formation-dewatering relationship. It is quite common to use at least a cationic polymer, often in combination with an anionic microparticle. In some cases, a fixative is also used. However, there is still debate on the optimal implementation of these systems. In particular, optimizing the contact time of the cationic polymer prior to addition of the anionic microparticle is still poorly understood. In this work, we investigate the effect of the contact time of a cationic polyacrylamide (CPAM) prior to addition of colloidal silica on the flocculation response in a flowing fiber suspension. The effect of using a fixative is also investigated. Focused beam reflectance measurements (FBRM) are combined with zeta-potential measurements for optimizing the addition levels of a two- and three-component system, as well as for elucidating the effect of contact time on CPAM performance. Trials are then performed on a pilot scale flow loop, where the time between addition of these two components is varied and the resulting flocculation response is characterized using high-speed filming and image anal. techniques. It is shown that the efficacy of CPAM can be improved through use of a fixative and that a longer CPAM contact time may be beneficial in terms of immediate flocculation; however, hydrodynamic shear tends to dominate the flocculation response regardless of contact time due to floc rupture.

Place, publisher, year, edition, pages
TAPPI Press, 2021
Keywords
cationic polyacrylamide colloidal silica flocculation approach flow contact time
National Category
Paper, Pulp and Fiber Technology
Identifiers
urn:nbn:se:ri:diva-56165 (URN)10.32964/tj20.1.39 (DOI)
Available from: 2021-09-01 Created: 2021-09-01 Last updated: 2021-09-01Bibliographically approved
De San Pio, I., Johansson, K. & Krochak, P. (2020). A novel predictive method for filler coflocculation with cellulose microfibrils. TAPPI Journal, 18(11), 653-664
Open this publication in new window or tab >>A novel predictive method for filler coflocculation with cellulose microfibrils
2020 (English)In: TAPPI Journal, ISSN 0734-1415, Vol. 18, no 11, p. 653-664Article in journal (Refereed) Published
Abstract [en]

Different strategies aimed at reducing the negative impact of fillers on paper strength have been the objective of many studies during the past few decades. Some new strategies have even been patented or commercialized, yet a complete study on the behavior of the filler flocs and their effect on retention, drainage, and formation has not been found in literature. This type of research on fillers is often limited by difficulties in simulating high levels of shear at laboratory scale similar to those at mill scale. To address this challenge, a combination of techniques was used to compare preflocculation (i.e., filler is flocculated before addition to the pulp) with coflocculation strategies (i.e., filler is mixed with a binder and flocculated before addition to the pulp). The effect on filler and fiber flocs size was studied in a pilot flow loop using focal beam reflectance measurement (FBRM) and image analysis. Flocs obtained with cationic polyacrylamide (CPAM) and bentonite were shown to have similar shear resistance with both strategies, whereas cationic starch (CS) was clearly more advantageous when coflocculation strategy was used. The effect of flocculation strategy on drainage rate, STFI formation, ash retention, and standard strength properties was measured. Coflocculation of filler with CPAM plus bentonite or CS showed promising results and produced sheets with high strength but had a negative impact on wire dewatering, opening a door for further optimization.

Place, publisher, year, edition, pages
TAPPI Press, 2020
Keywords
Bentonite, Flocculation, Cationic polyacrylamides, Cationic starches, Cellulose microfibrils, Co flocculations, Paper strengths, Predictive methods, Shear resistances, Strength property, Fillers, Drainage, Flocs, Formation, Impact, Retention
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-44778 (URN)10.32964/tj18.11.653 (DOI)2-s2.0-85083760510 (Scopus ID)
Note

Funding details: Universidad Politécnica de Madrid, UPM; Funding text 1: & Board Making” (Andritz, BillerudKorsnäs, Fibria, Hansol Paper, Holmen, ITC, Metsä Board, Metsä Fiber, Saica, Smurfit Kappa, Solenis, Stora Enso, Tetra Pak, and UPM) are acknowledged for their financial support.

Available from: 2020-06-15 Created: 2020-06-15 Last updated: 2021-06-14Bibliographically approved
De San Pio, I., Johansson, K. G. & Krochak, P. (2019). Filler co-flocculation with MFC: Novel predictive method. In: PaperCon 2019: Proceedings. Paper presented at PaperCon 2019. Proceedings of a conference held in Indianapolis, Indiana, USA, 5-8 May 2019. TAPPI Press, Article ID PA2-PF1.2.
Open this publication in new window or tab >>Filler co-flocculation with MFC: Novel predictive method
2019 (English)In: PaperCon 2019: Proceedings, TAPPI Press, 2019, article id PA2-PF1.2Conference paper, Published paper (Other academic)
Abstract [en]

Research has been undertaken in which a combination of different techniques was utilised to compare pre-flocculation (flocculant added to the filler prior to its addition to the pulp) with pre-mixing strategies, also called co-flocculation (chemicals added to a mixture of cellulose microfibrils (CMF) and filler. The pulp used was a mixture of 80% hardwood kraft pulp and 20% softwood kraft pulp. The filler was ground calcium carbonate (GCC), while the chemicals used included cationic polyacrylamide (CPAM), silica, bentonite, anionic PAM (APAM), cationic starch and CMF. Using the focused beam reflectance method (FBRM) enabled an in-depth and quick study of the filler floc behaviour at different dosages and mixing conditions, demonstrating that it was a very good tool as a pre-screening for different treatment alternatives. Clear differences in behaviour between different pre-flocculation and pre-mixing strategies were observed. For the pre-mixing strategy, the most promising results were achieved with CPAM plus bentonite and cationic starch systems. Although dewatering was negatively affected with pre-mixing, the mechanical properties were clearly improved. Flocs obtained with PCAM/bentonite had a similar resistance with both strategies, while cationic starch was clearly more advantageous when using the pre-mixing strategy.

Place, publisher, year, edition, pages
TAPPI Press, 2019
Keywords
filler; flocculation; microfibrillated cellulose; anionic polyacrylamide; cationic polyacrylamide; bentonite; silica; stock preparation
National Category
Paper, Pulp and Fiber Technology
Identifiers
urn:nbn:se:ri:diva-40587 (URN)
Conference
PaperCon 2019. Proceedings of a conference held in Indianapolis, Indiana, USA, 5-8 May 2019
Available from: 2019-10-28 Created: 2019-10-28 Last updated: 2021-06-14Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-0740-0328

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