| 1. |
- Grimm, Alejandro, et al.
(författare)
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Slagging and fouling characteristics during co-combustion of Scots pine bark with low-temperature dried pulp and paper mill chemical sludge
- 2019
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Ingår i: Fuel processing technology. - : Elsevier. - 0378-3820 .- 1873-7188. ; 193, s. 282-294
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Tidskriftsartikel (refereegranskat)abstract
- This paper shows how chemical sludge (CS) generated during wastewater treatment at a paperboard mill can be quickly dried at low-temperature and employed in bark-fired boilers to reduce slagging and corrosion problems. By using a cyclone-dryer operated at an inlet-air velocity of 110 m/s and a temperature of 90 degrees C, the dry-matter content of CS was increased from approximately 19 to 82%. The residence time of CS inside the cyclone was approximately 2 s when using the inlet-air velocity mentioned above. Disaggregation of the feedstock caused by collisions with the cyclone wall and between particles played a crucial role in enhancing the efficiency of heat and mass transfer. Three co-pelletized mixtures of Scots pine bark (SPB) and dried-CS were combusted in a 40 kW fixed-bed burner. Flue gas analysis was performed with a gas analyser. Coarse and fine ash were analysed by SEM-EDS and XRD. NOx, and SO2 emissions increased with increasing amount of CS in the mixtures. Mono combustion of SPB resulted in a large quantity of slag (i.e., molten ash) with a high degree of sintering (i.e., hardness of the slag), and ash deposits formed on heat transfer surfaces were rich in K2SO4 and KCI. Mixtures of SPB and CS were less prone to slagging, and the amount of alkali chloride in the deposits was reduced in favour of alkali sulphate formation.
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| 2. |
- Joelsson, Jonas M., et al.
(författare)
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From green forest to green commodity chemicals - Experiences from cross-sector collaboration and consequences for implementation
- 2017
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Ingår i: European Biomass Conf. Exhib. Proc.. - : ETA-Florence Renewable Energies. ; , s. 1899-1903
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Konferensbidrag (refereegranskat)abstract
- The purpose of this paper is to increase the understanding for the challenges and opportunities inherent to the cross-sectoral development of the bioeconomy. It takes the project “Forest Chemistry” as a case study, which was a collaboration project between Swedish forest industry and petrochemical industry clusters with the goal to develop forest based value chains for production of commodity chemicals. The project considered forest-based production of methanol, ethylene, propylene and butanol. We discuss the project and its outcomes from an innovation systems perspective applying a framework for technological innovation systems analysis. The original Forest Chemistry project also led to a number of spin-off projects, some of which are covered by this paper.
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| 3. |
- Stamm, Arne, et al.
(författare)
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A retrobiosynthesis-based route to generate pinene-derived polyesters
- 2019
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Ingår i: ChemBioChem (Print). - : Wiley. - 1439-4227 .- 1439-7633. ; 20, s. 1664-1671
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Tidskriftsartikel (refereegranskat)abstract
- Significantly increased production of biobased polymers is aprerequisite to replace petroleum-based materials towardsreaching a circular bioeconomy. However, many renewablebuilding blocks from wood and other plant material are notdirectly amenable for polymerization, due to their inert backbonesand/or lack of functional group compatibility with thedesired polymerization type. Based on a retro-biosyntheticanalysis of polyesters, a chemoenzymatic route from (@)-apinenetowards a verbanone-based lactone, which is furtherused in ring-opening polymerization, is presented. Generatedpinene-derived polyesters showed elevated degradation andglass transition temperatures, compared with poly(e-decalactone),which lacks a ring structure in its backbone. Semirationalenzyme engineering of the cyclohexanone monooxygenasefrom Acinetobacter calcoaceticus enabled the biosynthesis ofthe key lactone intermediate for the targeted polyester. As aproof of principle, one enzyme variant identified from screeningin a microtiter plate was used in biocatalytic upscaling,which afforded the bicyclic lactone in 39% conversion in shakeflask scale reactions.
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| 4. |
- Todorovic, Tijana, 1986-, et al.
(författare)
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A fully bio-based wood adhesive valorising hemicellulose-rich sidestreams from the pulp industry
- 2021
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Ingår i: Green Chemistry. - : Royal Society of Chemistry (RSC). - 1463-9262 .- 1463-9270. ; 23:9, s. 3322-3333
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Tidskriftsartikel (refereegranskat)abstract
- Today, most wood adhesives are prepared from fossil-based polymers and contain hazardous components,e.g., formaldehyde. With the growing environmental concern there is an urge to develop bio-based and harmless substitutes. In this study, the ambition is to explore and valorise hemicelluloses, a biproduct from pulping, as the main component in wood adhesives. Wood adhesives were prepared from different sources: xylan from beech wood, hemicellulose-rich liquids obtained from hydrolysis of hardwood, and ultrafiltered softwood hemicellulose recovered from the process water of a thermomechanical pulp mill. Hemicelluloses themselves do not exhibit sufficient bonding performance, but excellent bond strength and water resistance were obtained in combination with poly(vinyl amine). It was also demonstrated that chitosan can be used as a bio-based amino-functional alternative to synthetic poly(vinyl amine), with similar or superior properties. Hemicelluloses alone show insufficient water resistance, but hemicelluloses in combination with chitosan exhibit exceptionally good bonding performance, especially regarding water resistance. Adhesives prepared from liquids rich in hardwood- and softwood hemicelluloses showed similar bond strength in combination with amino-functional polymers (poly(vinyl amine) and chitosan), regardless of their differences in structure. The current study constitutes an example on how sidestreams from the pulp industry in combination with chitosan can be used to substitute fossil-based materials in the quest for a more sustainable society.
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