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Ferritsius, Rita
Publications (10 of 25) Show all publications
Ferritsius, O., Ferritsius, R. & Rundlof, M. (2018). Average fibre length as a measure of the amount of long fibres in mechanical pulps - ranking of pulps may shift. Nordic Pulp & Paper Research Journal, 33(3), 468-481
Open this publication in new window or tab >>Average fibre length as a measure of the amount of long fibres in mechanical pulps - ranking of pulps may shift
2018 (English)In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 33, no 3, p. 468-481Article in journal (Refereed) Published
Abstract [en]

The purpose of this study was to investigate the applicability of different ways of calculating the average fibre length based on length measurements of individual particles of mechanical pulps. We have found that the commonly used average length-weighted fibre length, which is based on the assumption that coarseness is constant for all particles, as well as the arithmetic average, may lead to erroneous conclusions in real life as well as in simulations when used as a measure of the amount of long fibres. The average length-length-weighted fibre length or a weighting close to that, which to a larger extent suppresses the influence of shorter particles, is a relevant parameter of the "length" factor, i. e. amount of long fibres. Our findings are based on three studies: refining of different assortments of wood raw material in a mill; data from LC refining in mill of TMP, including Bauer McNett fractionation; mixing of pulps with different fibre length distributions. If the acceptable average fibre length for different products can be lowered, the possibility of reducing the specific energy input in refining will increase. Therefore, we need a reliable and appropriate way to assess the "length" factor.

Keywords
average fibre length, fibres, fines, long fibres, mechanical pulp, weighted length
National Category
Chemical Engineering
Identifiers
urn:nbn:se:miun:diva-35160 (URN)10.1515/npprj-2018-3058 (DOI)000450923900013 ()2-s2.0-85047975413 (Scopus ID)
Available from: 2018-12-11 Created: 2018-12-11 Last updated: 2019-03-15Bibliographically approved
Fiskari, J., Ferritsius, R., Osong, S. H., Persson, A., Höglund, T. & Norgren, M. (2018). Deep Eutectic Solvent Treatment to Low-Energy TMP to Produce Fibers for Papermaking. In: IMPC 2018: . Paper presented at International Mechanical Pulping Conference (IMPC) 2018, May 27-30, 2018, Trondheim, Norway. Trondheim, Norway
Open this publication in new window or tab >>Deep Eutectic Solvent Treatment to Low-Energy TMP to Produce Fibers for Papermaking
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2018 (English)In: IMPC 2018, Trondheim, Norway, 2018Conference paper, Published paper (Refereed)
Abstract [en]

The aim of this research was to gain a better understanding on whether a novel process based on low-energy thermo-mechanical pulp (TMP) process followed by a chemical treatment with deep eutectic solvents (DESs) could produce fibers suitable for papermaking. In full scale production, these fibers could be produced at a much lower capital and operational costs, especially when utilizing existing TMP plants which are under the threat to be shut down or have already been shut down due to a decreasing demand for newsprint and other wood-containing papers.The efficiency of several DES treatments under various temperatures and times were evaluated by carrying out experiments in standard Teflon-lined autoclaves. A few tests were also performed in a unique nonstandard flow extractor. Pulp samples were characterized for their cellulose, hemicellulose and lignin contents. Moreover, tensile index was measured both before and after pulp refining. Depending on the solvent, the response of mechanical pulp varied, especially in terms of hemicellulose dissolution. Lactic acid, oxalic acid and urea, all in combination with choline chloride ([Ch]Cl) as the hydrogen bond acceptor, dissolved about 50% of the lignin of the low-energy TMP fibers under the tested conditions. The mixture of malic acid and [Ch]Cl was less effective in lignin dissolution. The mixture of urea and [Ch]Cl exhibited only a minor loss in hemicellulose content, when compared to the other tested DESs. Although 50% of the lignin was dissolved with minor loss in hemicellulose no improvement in tensile strength was observed, as it was rather the opposite. Another benefit with the mixture of urea and [Ch]Cl was that this DES did not appear to be corrosive to stainless steel. All other tested DESs—which were also quite acidic—were observed to be corrosive. Moreover, this DES-related corrosion was found to intensify at elevated temperatures.When chips were used as starting material with otherwise the same conditions almost no lignin was dissolved. This suggests that low-energy mechanical pulp is likely to be a good starting material for extracting lignin using DESs.

Place, publisher, year, edition, pages
Trondheim, Norway: , 2018
National Category
Paper, Pulp and Fiber Technology
Identifiers
urn:nbn:se:miun:diva-34679 (URN)
Conference
International Mechanical Pulping Conference (IMPC) 2018, May 27-30, 2018, Trondheim, Norway
Available from: 2018-10-09 Created: 2018-10-09 Last updated: 2018-10-09Bibliographically approved
Ferritsius, O., Ferritsius, R., Rundlöf, M., Engberg, B. A. & Engstrand, P. (2018). The Independent State of Fibres in Relation to the Mechanical Pulping World. In: IMPC 2018: . Paper presented at International Mechanical Pulping Conference (IMPC) 2018, May 27-30, 2018, Trondheim, Norway. Trondheim, Norway
Open this publication in new window or tab >>The Independent State of Fibres in Relation to the Mechanical Pulping World
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2018 (English)In: IMPC 2018, Trondheim, Norway, 2018Conference paper, Published paper (Refereed)
Abstract [en]

Paper and wood are highly inhomogeneous materials. When describing the mechanical pulp itself, we allcommonly ignore that it is an inhomogeneous material. We have realized that just a very small fraction of stifffibres are enough to impair the printability of the product. In this paper we share some of our reflections andattempts how to describe the inhomogeneous nature of mechanical pulps. A method denoted BIN is underdevelopment based on independent common factors and paying attention to the inhomogeneity of the material.The method may give the possibility to describe the nature of TMP/CTMP/SGW in a more relevant way comparedto todays practice. Hence the paper and board makers may be able to deliver more uniform products at “goodenough” level at lower costs. We have realized that because a method or opinion is well spread (sometimes usedby almost everybody) it does not necessarily mean that it is relevant. A couple of myths have been reflected uponand in our opinion they remain just myths. By putting more attention to reality and describing mechanical pulp asan inhomogeneous material we hope to be able to rid ourselves and the mechanical pulping community of someother myths circulating (some still to be discovered).

Place, publisher, year, edition, pages
Trondheim, Norway: , 2018
National Category
Paper, Pulp and Fiber Technology
Identifiers
urn:nbn:se:miun:diva-34680 (URN)
Conference
International Mechanical Pulping Conference (IMPC) 2018, May 27-30, 2018, Trondheim, Norway
Available from: 2018-10-09 Created: 2018-10-09 Last updated: 2018-10-09Bibliographically approved
Ferritsius, R., Ferritsius, O., Hill, J., Karlström, A. & Eriksson, K. (2018). TMP properties and refiner conditions in a CD82 chip refiner at different operation points. Part II: Comparison of the five tests. Nordic Pulp & Paper Research Journal, 33(1), 82-94
Open this publication in new window or tab >>TMP properties and refiner conditions in a CD82 chip refiner at different operation points. Part II: Comparison of the five tests
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2018 (English)In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 33, no 1, p. 82-94Article in journal (Refereed) Published
Abstract [en]

This paper is part two of a study on a CD 82 TMP chip refiner where relations between changes in the process conditions and changes in the properties of the produced pulp are investigated. Focus is on the ratio between tensile index and specific energy consumption when results from five tests are compared. Pulp properties were measured for composite pulp samples taken from the refiner blow line. Residence times and pulp consistencies were estimated by use of the extended entropy model. Clearly, an increase in specific energy does not necessarily implicate an increase in strength properties of the pulp produced. It is of high importance to have access to information about the refining zone conditions when searching for an optimal operation point in terms of the ratio between tensile index and specific energy. In these tests, this ratio had a maximum at about 55 % measured blow line consistency. Unfavourable operating conditions were identified at high pulp consistencies, especially after the FZ, where pulp consistencies well above 70 % were observed. The estimated residence time for each refining zone responded differently when applying changes in production rate, plate gaps and dilution water flow rates. In conclusion, the results associated with estimated pulp consistencies where easier to interpret compared with results for residence times, implying that additional tests are required for the latter variable. In addition to tensile index, pulp properties like freeness, Somerville shives and light scattering coefficient were included in the analysis. 

Keywords
CD 82 refiner, entropy model, fibre properties, handsheet properties, plate gap, pulp quality, residence time, specific energy, temperature measurements, TMP refiners
National Category
Chemical Engineering
Identifiers
urn:nbn:se:miun:diva-34543 (URN)10.1515/npprj-2018-3003 (DOI)000450919200010 ()2-s2.0-85048002264 (Scopus ID)
Available from: 2018-09-27 Created: 2018-09-27 Last updated: 2018-12-11Bibliographically approved
Ferritsius, R., Ferritsius, O., Hill, J., Karlström, A. & Eriksson, K. (2018). TMP properties and refining conditions in a CD82 chip refiner. Part I: Step changes of process variables, description of the tests. Nordic Pulp & Paper Research Journal, 33(1), 69-81
Open this publication in new window or tab >>TMP properties and refining conditions in a CD82 chip refiner. Part I: Step changes of process variables, description of the tests
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2018 (English)In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 33, no 1, p. 69-81Article in journal (Refereed) Published
Abstract [en]

The study explores how changes in process variables, residence time and pulp consistency in refining influence the pulp properties. The equipment utilized in this study was a conical disc chip refiner (RGP82CD) producing thermomechanical pulp (TMP). The focus was on the ratio between tensile index and specific energy consumption. Pulp properties were measured for composite pulp samples taken from the refiner blow line. Residence times and pulp consistencies were estimated by use of the extended entropy model. This showed that the CD-refiner, with the flat and conical refining zone, has a process performance similar to that of a two-stage refiner set-up, and that the consistency in both refining zones is of high importance. Comparing different periods revealed that even if the values of measured blow line consistency are similar, significant differences in the estimated consistency in the flat zone can prevail. Therefore, only monitoring blow line consistency is not enough. Specifically, it was found that the pulp consistency after the flat zone could be very high, considerably higher than in the blow line, and this could have negative effects on tensile index and fibre length. 

Keywords
conical disc refiner, energy, entropy model, fibre properties, pulp consistency, pulp properties, residence time, temperature profile, TMP
National Category
Chemical Engineering
Identifiers
urn:nbn:se:miun:diva-34542 (URN)10.1515/npprj-2018-3002 (DOI)000450919200009 ()2-s2.0-85047997941 (Scopus ID)
Available from: 2018-09-27 Created: 2018-09-27 Last updated: 2018-12-11Bibliographically approved
Sandberg, C., Ferritsius, O. & Ferritsius, R. (2017). Energy efficiency in mechanical pulping. In: : . Paper presented at 10th Fundamental Mechanical Pulping Research Seminar, Jyväskylä, Finland, 13–14 of June, 2017.
Open this publication in new window or tab >>Energy efficiency in mechanical pulping
2017 (English)Conference paper, Published paper (Refereed)
National Category
Paper, Pulp and Fiber Technology
Identifiers
urn:nbn:se:miun:diva-34661 (URN)
Conference
10th Fundamental Mechanical Pulping Research Seminar, Jyväskylä, Finland, 13–14 of June, 2017
Available from: 2018-10-09 Created: 2018-10-09 Last updated: 2018-10-09Bibliographically approved
Ferritsius, O., Ferritsius, R., Hill, J., Karlström, A., Ferritsius, J. & Eriksson, K. (2017). Process considerations and its demands on TMP property measurements - A study on tensile index. Nordic Pulp & Paper Research Journal, 32(1), 45-53
Open this publication in new window or tab >>Process considerations and its demands on TMP property measurements - A study on tensile index
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2017 (English)In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 32, no 1, p. 45-53Article in journal (Refereed) Published
Abstract [en]

As a vital component in the strive towards improved energy efficiency in the operation of TMP refining processes, this work highlights the importance of well- designed procedures when collecting and analysing pulp properties with respect to process conditions. Process data and pulp from a CD82 chip refiner have been used to show that tensile index has strong covariance with fibre residence time calculated by the extended entropy model. A combination of theoretical and practical analysis methods has shown that, in order to assure representative, reliable results, pulp sampling procedures should comprise composite pulp samples collected during a sampling period of about three minutes. In addition, at least four subsequently collected composite pulp samples should be included in the analysis to effectively dampen effects from fast process variations as well as from slow process drift. An in-depth study on tensile index measurements clarifies that 40-60 strips should be used in the case we studied regardless if machine made paper or handsheets are considered.

Keywords
Accuracy, Composite pulp samples, Pulp sampling procedure, Residence time, Tensile index, TMP
National Category
Chemical Engineering
Identifiers
urn:nbn:se:miun:diva-30666 (URN)10.3183/NPPRJ-2017-32-01-p045-053 (DOI)000398384400006 ()2-s2.0-85016389492 (Scopus ID)
Available from: 2017-04-26 Created: 2017-04-26 Last updated: 2017-06-09Bibliographically approved
Eriksson, K., Ferritsius, R., Ferritsius, O. & Hill, J. (2016). Benefits from improved stability in process conditions and pulp properties-a double disc refiner case study. In: International Mechanical Pulping Conference 2016, IMPC 2016: . Paper presented at International Mechanical Pulping Conference 2016, IMPC 2016; Jacksonville; United States; 26 September 2016 through 28 September 2016 (pp. 317-327). TAPPI Press
Open this publication in new window or tab >>Benefits from improved stability in process conditions and pulp properties-a double disc refiner case study
2016 (English)In: International Mechanical Pulping Conference 2016, IMPC 2016, TAPPI Press, 2016, p. 317-327Conference paper, Published paper (Refereed)
Abstract [en]

The purpose of this case study was to explore the potential for reduced energy consumption by improved process control. The application was HC post-refining of TMP in double-disc refiners. Based on data from both continuous production and from step-response tests, a thorough analysis of process performance was conducted. It was found that a significant proportion of the process disturbances, as reflected in the refiner motor load, could be successfully dampened through stabilizing measures on the basic control level. The remaining disturbances was found to be generated inside the refiner itself. In order for these disturbances to be dampened, measurements that can characterize the conditions inside the refining zone are necessary. Given the present design and instrumentation of the process, dynamic modelling of refiner motor load was performed and for fiber properties, muhivariate modeling methods were used to derive expressions for the independent variables Fl and F2. Taken together, evaluation of the models gave directions on how to further improve the process stability and indicated a potential for reduced energy consumption.

Place, publisher, year, edition, pages
TAPPI Press, 2016
National Category
Chemical Engineering
Identifiers
urn:nbn:se:miun:diva-29832 (URN)2-s2.0-85006380402 (Scopus ID)9781510830738 (ISBN)
Conference
International Mechanical Pulping Conference 2016, IMPC 2016; Jacksonville; United States; 26 September 2016 through 28 September 2016
Note

Funding details: Swedish Research and Development program

Available from: 2017-01-09 Created: 2017-01-09 Last updated: 2017-01-09Bibliographically approved
Ferritsius, R., Sandberg, C., Ferritsius, O., Rundlöf, M., Daniel, G., Mörseburg, K. & Fernando, D. (2016). Development of Fiber Properties in Full Scale HC and LC Refining. In: TAPPI conference proceedings: . Paper presented at 2016 International Mechanical Pulping (IMPC) Conference. TAPPI Press
Open this publication in new window or tab >>Development of Fiber Properties in Full Scale HC and LC Refining
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2016 (English)In: TAPPI conference proceedings, TAPPI Press, 2016Conference paper, Published paper (Refereed)
Place, publisher, year, edition, pages
TAPPI Press, 2016
National Category
Paper, Pulp and Fiber Technology
Identifiers
urn:nbn:se:miun:diva-34668 (URN)
Conference
2016 International Mechanical Pulping (IMPC) Conference
Available from: 2018-10-09 Created: 2018-10-09 Last updated: 2018-10-09Bibliographically approved
Eriksson, K., Ferritsius, J., Ferritsius, O., Ferritsius, R., Hill, J., Karlstrorrp, A. & Merseburg, K. (2016). Proper pulp sampling pre-requisite to any pulp property assessment. In: International Mechanical Pulping Conference 2016, IMPC 2016: . Paper presented at International Mechanical Pulping Conference 2016, IMPC 2016; Jacksonville; United States; 26 September 2016 through 28 September 2016 (pp. 1-11). TAPPI Press
Open this publication in new window or tab >>Proper pulp sampling pre-requisite to any pulp property assessment
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2016 (English)In: International Mechanical Pulping Conference 2016, IMPC 2016, TAPPI Press, 2016, p. 1-11Conference paper, Published paper (Refereed)
Place, publisher, year, edition, pages
TAPPI Press, 2016
National Category
Chemical Engineering
Identifiers
urn:nbn:se:miun:diva-29837 (URN)2-s2.0-85006434746 (Scopus ID)978-151083073-8 (ISBN)
Conference
International Mechanical Pulping Conference 2016, IMPC 2016; Jacksonville; United States; 26 September 2016 through 28 September 2016
Note

Conference Paper

Available from: 2017-01-09 Created: 2017-01-09 Last updated: 2017-01-09Bibliographically approved
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