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Publications (3 of 3) Show all publications
Drotz, M., Sjöstedt, A., Verma, M. & Verma, P. (2022). A laboratory investigation of Superheated Steam Dried pulps. In: TAPPICon Conference 2022: . Paper presented at TAPPICon 2022. TAPPI Press
Open this publication in new window or tab >>A laboratory investigation of Superheated Steam Dried pulps
2022 (English)In: TAPPICon Conference 2022, TAPPI Press , 2022Conference paper, Published paper (Refereed)
Abstract [en]

Superheated steam drying is used commercially for lumber, coal, peat, sludges, but has limited installations towards market pulp applications. The technology has the potential for higher drying rates, lower energy consumption, better product quality, and safe operation. In this investigation, a superheated steam dryer (EXERGYPSSD®) was used for evaluation of wet pulp samples collected from pulp mills for comparison with conventional drying techniques. The evaluation of the superheated steam dried pulps indicated that there are potential quality benefits with the technology. Improvements of bulk and absorption capacity was achieved, but more laboratory, and pilot tests are needed to optimize the technology even more regarding pressure, temperature, and residence time in the dryer.

Place, publisher, year, edition, pages
TAPPI Press, 2022
Keywords
Driers; Drying; Quality Control; Superheated Steam; Dryers (equipment); Drying; Pulp; Quality control; Steam; Drying rates; Laboratory investigations; Low energy consumption; Market pulp; Products quality; Pulp samples; Safe operation; Superheated steam; Superheated steam dryer; Superheated steam drying; Energy utilization
National Category
Paper, Pulp and Fiber Technology
Identifiers
urn:nbn:se:ri:diva-68120 (URN)2-s2.0-85175647494 (Scopus ID)
Conference
TAPPICon 2022
Available from: 2023-12-07 Created: 2023-12-07 Last updated: 2023-12-07Bibliographically approved
Mitraka, E., Vagin, M., Sjöstedt, A., Berggren, M., Håkansson, K., Jonsson, M. & Crispin, X. (2019). PEDOT-Cellulose Gas Diffusion Electrodes for Disposable Fuel Cells. Advanced Sustainable Systems, 3(12), Article ID 1900097.
Open this publication in new window or tab >>PEDOT-Cellulose Gas Diffusion Electrodes for Disposable Fuel Cells
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2019 (English)In: Advanced Sustainable Systems, ISSN 2366-7486, Vol. 3, no 12, article id 1900097Article in journal (Refereed) Published
Abstract [en]

The mass implementation of renewable energy sources is limited by the lack of energy storage solutions operating on various timescales. Electrochemical technologies such as supercapacitors and batteries cannot handle long storage time because of self-discharge issues. The combination of fuel storage technology and fuel cells is an attractive solution for long storage times. In that context, large-scale fuel cell solutions are required for massive energy storage in cities, which leads to possible concepts such as low-cost disposable fully organic membrane assemblies in fuel cells to avoid regeneration of expensive poisoned electrodes. Here, the formation of an organic gas diffusion electrode (GDE) fabricated by paper-making production, combined with in situ polymerization is demonstrated for the first time. Cellulose is used as a 3D scaffold functionalized with poly(3,4-ethylenedioxythiophene) (PEDOT) serving as both an electrical conductor and an electrocatalyst of high efficiency for the oxygen reduction reaction. The PEDOT-cellulose porous GDE is implemented in a membrane assembly and demonstrated in a H2-O2 fuel cell. The demonstration of low-cost material/manufacturing that is environmentally friendly is a paradigm shift in the development of fuel cells for a sustainable society.

Place, publisher, year, edition, pages
Wiley-VCH Verlag, 2019
Keywords
cellulose, gas diffusion electrodes, in situ polymerization, PEDOT, PEM fuel cells
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-40916 (URN)10.1002/adsu.201900097 (DOI)2-s2.0-85075434266 (Scopus ID)
Available from: 2019-12-10 Created: 2019-12-10 Last updated: 2023-05-23Bibliographically approved
Sjöstedt, A., Wohlert, J., Larsson, P. T. & Wågberg, L. (2015). Structural changes during swelling of highly charged cellulose fibres. Cellulose, 22(5), 2943-2953
Open this publication in new window or tab >>Structural changes during swelling of highly charged cellulose fibres
2015 (English)In: Cellulose, ISSN 0969-0239, E-ISSN 1572-882X, Vol. 22, no 5, p. 2943-2953Article in journal (Refereed) Published
Abstract [en]

Structural changes of fibrils and fibril aggregates in the fibre wall were studied after oxidation of the cellulose by 2,2,6,6-tetramethyl-1-piperidinyloxy to high charge densities (highest charge density: 1300 μeq/g). The increase in pore volume was measured by mini-WRV at two different pH levels, and the supramolecular structure in the fibre wall in terms of aggregate size, specific surface area and average pore size was measured by solid state NMR, DVS desorption and BET N2 gas adsorption. A structural change in the arrangement of the fibrils inside the fibril aggregates was observed although the oxidation did not lead to a complete liberation of individual fibrils, i.e. they still exist as an aggregated structure after oxidation. Theoretical estimates suggest that the electrostatic repulsion energy connected with the increase in surface charge of the fibrils can be sufficient to gradually separate the fibrils enough to expose all fibril surfaces to oxidation chemicals.

Keywords
Cellulose fibres, Nano structure, TEMPO oxidation, Fibril, Fibril aggregates, CNF, Cellulose nano fibrils, Specific surface area
National Category
Paper, Pulp and Fiber Technology Polymer Technologies
Identifiers
urn:nbn:se:ri:diva-758 (URN)10.1007/s10570-015-0701-4 (DOI)2-s2.0-84941416963 (Scopus ID)
Available from: 2016-10-24 Created: 2016-08-03 Last updated: 2023-05-09Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0003-3474-6858

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