Change search
ReferencesLink to record
Permanent link

Direct link
The Initial Phase of Sodium Bisulfite Pulping of Pine, Part II
Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences.ORCID iD: 0000-0003-4841-2568
Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences. (Pulp technology)
MoRe Research, Örnsköldsvik, Sweden.
Domsjö Fabriker AB, Örnsköldsvik, Sweden.
2016 (English)In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 31, no 3, 379-385 p.Article in journal (Refereed) Published
Abstract [en]

Single stage sodium bisulfite cooking of pine was carried out to investigate the influence of time and temperature in the initial phase of the cook. The cooking experiments were carried out using either a lab or a mill prepared cooking acid and the initial stage of the cook was extended up to 5 h cooking time. The impact of temperature on wood components and side reactions was analyzed between 142°C and 165°C. Arrhenius equation was used to determine the influence of temperature on wood components during the initial phase of bisulfite cooking and the activation energy was calculated for delignification rate, cellulose degradation and hemicellulose dissolution with regard to glucomannan and xylan. The extent of extractives removal at different temperature and time was also analyzed.

Place, publisher, year, edition, pages
Härnösand: Mittuniversitetet , 2016. Vol. 31, no 3, 379-385 p.
Keyword [en]
Bisulfite pulping, cellulose, extractives, glucomannan, kinetics, lignin, pine, sulfate, thiosulfate and xylan.
National Category
Chemical Engineering
Research subject
Chemical Engineering
Identifiers
URN: urn:nbn:se:kau:diva-37303OAI: oai:DiVA.org:kau-37303DiVA: diva2:845059
Funder
Knowledge Foundation
Note

This paper was in manuscript form in Raghu Deshpande's licentiate thesis.

Available from: 2015-08-10 Created: 2015-08-06 Last updated: 2016-11-24Bibliographically approved
In thesis
1. The initial phase of the sodium bisulfite pulping of softwood dissolving pulp
Open this publication in new window or tab >>The initial phase of the sodium bisulfite pulping of softwood dissolving pulp
2015 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

The sulfite pulping process is today practised in only a small number of pulp mills around the globe and the number of sulfite mills that use sodium as the base (cation) is less than five. However, due to the increasing interest in the wood based biorefinery concept, the benefits of sulfite pulping and especially the sodium based variety, has recently gained a lot of interest. It was therefore considered to be of high importance to further study the sodium based sulfite process to investigate if its benefits could be better utilized in the future in the production of dissolving pulps. Of specific interest was to investigate how the pulping conditions in the initial part of the cook (≥ 60 % pulp yield) should be performed in the best way.

Thus, this thesis is focused on the initial phase of single stage sodium bisulfite cooking of either 100 % spruce or 100 % pine wood chips. The cooking experiments were carried out with either a lab prepared or a mill prepared cooking acid and the temperature and cooking time were varied. Activation energies for different wood components were investigated as well as side reactions concerning the formation of thiosulfate and sulfate.

Abstract [en]

Single stage sodium bisulfite cooking was carried out on either spruce or pine wood chips to investigate the influence of several process parameters in the initial phase of such a cook i.e. between 100 % and 60 % pulp yield. The cooking experiments were carried out with either a lab prepared or a mill prepared cooking acid and the temperature and time in the initial stage were varied. The influence of dissolved organics and inorganics components in the cooking liquor on the final pulp properties and side reactions were investigated. The impact of temperature and time on the pulp components were analyzed with respect to carbohydrates, lignin, extractives and thiosulfate. Kinetic equations were developed and the activation energies for delignification and carbohydrate dissolution were calculated using the Arrhenius equation.

It was found that if using a mill prepared cooking acid, this had a beneficial effect with respect to side reactions, better extractives removal and higher pH stability during the cook, compared to a corresponding cook with a lab prepared cooking acid. Cooking with mill prepared and lab prepared cooking acids showed the same behaviour with respect to delignification and carbohydrate degradation, but the lab acid experiments resulted in a higher thiosulfate formation during the cook. The cellulose yield was not affected at all during the initial phase of the sulfite cook verifying earlier results by other researchers. The temperature had an influence on both the delignification rate and the rate of hemicelluloses removal.  The corresponding activation energies were found to increase in the following order; cellulose, xylan, glucomannan and lignin.

Place, publisher, year, edition, pages
Karlstad: Karlstads universitet, 2015. 54 p.
Series
Karlstad University Studies, ISSN 1403-8099 ; 2015:34
Keyword
Activation energy, bisulfite pulping, cellulose, delignification, extractives, glucomannan, hemicelluloses, lignin, pine, spruce, thiosulfate, total SO2, xylan
National Category
Other Chemical Engineering Chemical Process Engineering
Research subject
Chemical Engineering
Identifiers
urn:nbn:se:kau:diva-36494 (URN)978-91-7063-652-3 (ISBN)
Presentation
2015-09-25, 9 C 203, Karlstad University, Karlstad, 13:00 (English)
Opponent
Supervisors
Funder
Knowledge Foundation
Note

Artikel 1: "The Initial Phase of Sodium Bisulfite Pulping of Spruce: Part 1" ingick i avhandlingen som manuskript. Nu publicerad.

Available from: 2015-09-04 Created: 2015-06-17 Last updated: 2016-03-31Bibliographically approved

Open Access in DiVA

No full text

Search in DiVA

By author/editor
Deshpande, RaghuGermgård, Ulf
By organisation
Department of Engineering and Chemical Sciences
In the same journal
Nordic Pulp & Paper Research Journal
Chemical Engineering

Search outside of DiVA

GoogleGoogle Scholar

Total: 27 hits
ReferencesLink to record
Permanent link

Direct link