| 1. |
- Anheden, Marie, et al.
(författare)
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The role of intermediate products in biorefinery development : Kraft lignin and pyrolysis oil as intermediates for production of naphtha cracker feed from forest-based raw materials
- 2015
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Ingår i: NWBC 2015. Proceedings of the 6th Nordic Wood Biorefinery Conference held in Helsinki, Finland, 20-22 Oct. 2015. - 9789513883539 ; , s. 210-219
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Konferensbidrag (refereegranskat)abstract
- Research has been undertaken to estimate key performance factors important for development of biomass value chains with intermediate products. In the case selected, the end-product had to be suitable as feed product to a naphtha cracker. Pyrolysis oil and kraft lignin were the investigated intermediates, while yield, cost and carbon dioxide footprint were compared with direct production of bio naphtha from forest residues at the petrochemical plant and fossil naphtha. Three bio-based value chains were evaluated: without intermediate; with pyrolysis oil as intermediate; and with kraft lignin separated from black liquor as intermediate. Innventia AB's simulation model in WinGEMS was used to simulate the hypothetical reference pulp mill and the effects of integration with the lignin removal (LignoBoost) and pyrolysis equipment. It has been concluded that the use of intermediates produced integrated with decentralised local industrial plants could reduce total cost and carbon dioxide emissions of transporting forest based biomass to a centrally located conversion plant. However, the economic benefit was not very large compared with the overall value chain cost to produce the final product. Kraft lignin from pulp production was a very interesting intermediate, particularly in the case of the economic benefit
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| 2. |
- Baker, Darren A., et al.
(författare)
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Opportunities in lignin based carbon fibre
- 2015
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Ingår i: NWBC 2015. - Espoo : VTT. - 9789513883539 ; , s. 244-251
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Konferensbidrag (refereegranskat)abstract
- Innventia AB's LignoBoost process enables the extraction of high purity lignin efficiently from the black liquor in kraft mills. A stream of black liquor is taken from the evaporation plant and the lignin is precipitated by acidification and filtered. The filter cake is redispersed and acidified and the resulting slurry is filtered and washed. High purity lignin can be produced at several scales, namely 10g, 1kg, 10kg and over 1,000kg. Innventia has invested significantly to demonstrate the potential of lignin as a viable feedstock for carbon fibre manufacture. Initially, the fibre melt spinning performance of the lignin is assessed using single filament melt extrusion and then melt spinning is performed at the multifilament scale, where fine fibres can be produced for conversion to carbon fibre. Oxidative thermostabilisation of the lignin fibres is carried out so that carbonisation can proceed. The effects of thermal treatment programmes and tensioning have been studied by using either thermomechanical analysis or by using test equipment specially designed to monitor carbonisation profiles with either stress or strain control. In addition, continuous processes for the conversion of lignin fibre to carbon fibre are being developed.
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| 3. |
- Conte, Ricardo Pezoa, et al.
(författare)
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Bioethanol production from the green alga ulva rigida and the brown algae macrocystis pyrifera
- 2015
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Ingår i: NWBC 2015. - : VTT Technical Research Centre of Finland. - 9789513883539 ; , s. 319-325
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Konferensbidrag (refereegranskat)abstract
- Macroalgae are suitable bioresources to be explored as raw material for bioethanol production, as about 40 wt.% of its mass is composed of carbohydrates and they completely lack lignin. In this work the simultaneous saccharification and fermentation (SSF) of the green alga Ulva rigida and the brown alga Macrocystis pyrifera was performed. The algae were initially pretreated in deionized water or diluted sulfuric acid at 125°C in an autoclave for 60 min, respectively. Commercial cellulolytic enzymes and yeast were used for ethanol production. The carbohydrate composition of the fresh alga, pretreated alga and glucose and ethanol concentrations in the SSF processing are given. The water pretreatment solubilized 82 wt.% of the ulvan (rhamno-glucuroxylan) contained in U. rigida and 73 wt.% of the glucan remained in the residue. The diluted acid treatment removed 93 wt.% of the carbohydrates contained in U. rigida. The SSF of U. rigida pretreated with water produced 0.47 g EtOH/g sugar, with a 92 wt.% theoretical yield. In turn, water and diluted acid pretreatment of M. pyrifera increased 8.4 and 14.8 fold the carbohydrate content in the pretreated alga compared to the SSF of the fresh alga. The SSF of M. pyrifera pretreated with dilute sulfuric acid produced 0.15 g EtOH/g sugar, 29 wt.% theoretical yield. The production of ethanol was demonstrated for U. rigida and M. pyrifera with mild pretreatments. Especially in case of U. rigida simple water treatment allows to isolate ulvan for other purposes and efficiently ferment the remaining fibers.
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| 4. |
- Durruty, Julie, 1988, et al.
(författare)
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Local filtration properties of kraft lignin : influence of ligning-carbohydrate complex
- 2015
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Ingår i: 6th Nordic Wood Biorefinery Conference, NWBC 2015. - : VTT Technical Research Centre of Finland. - 9789513883539 ; , s. 301-308
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Konferensbidrag (refereegranskat)abstract
- The influence of lignin and xylan interactions on the filtration properties of precipitated LignoBoost lignin is investigated. LignoBoost lignin was dissolved together with added xylan and then re-precipitated. The resulting lignin-xylan suspension was more difficult to filter than the original LignoBoost lignin, although the mix also formed more porous filter cakes. One of the possible explanations suggested by the findings presented in this paper is that xylan is sorbed at the surface of the lignin agglomerates, increasing the contact area between solid and liquid and making the particles local structure more porous.
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| 5. |
- Jacobs, Anna, Ph. D., et al.
(författare)
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Lignin properties for the biorefinery, and their analytical challenges
- 2015
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Ingår i: NWBC 2015. - Espoo : VTT. - 9789513883539 ; , s. 203-204
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Konferensbidrag (refereegranskat)abstract
- The lack of official standardised methods for lignin has meant that the results from analysis of lignin properties are largely dependent on which method or laboratory that is used. Therefore, relevant and harmonised analytical methods are essential to allow producers of biorefinery products to prepare specifications for their products and to improve the possibilities for systematic development of process and product. The current status of the most important methods for lignin characterisation has been evaluated together with method development or method adaption in order to meet the requirements for high-value lignin products.
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| 6. |
- Mattsson, Tuve, et al.
(författare)
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Towards a wood based material biorefinery - A demonstrator
- 2015
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Ingår i: 6th Nordic Wood Biorefinery Conference, NWBC 2015. - : VTT Technical Research Centre of Finland. - 9789513883539 ; , s. 92-101
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Konferensbidrag (refereegranskat)abstract
- Wood, the most abundant ligno-cellulosic raw material available, is a key potential feedstock for production of more sustainable alternatives to fossil-based materials. However advances within the fields of extraction and treatment processes within what is often referred to as the biorefinery concept is essential to allow for such transition. In this study, several different methods for the extraction and separation of wood constituents have been combined in a single process with the purpose of achieving a high overall efficiency of material extraction and utilisation. The work builds on several activities within the Wallenberg Wood Science Center (WWSC). The aim is to present a laboratory-scale demonstrator that illustrates how the different constituents can be separated from the wood matrix for later use in the production of bio-based materials and chemicals. The process steps involved have been tested as integral steps in a linked process for a scale of operations that range from the kilogram-scale down to the gram-scale. Industrially chipped softwood, containing mainly spruce with some pine, was used as raw material.
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| 7. |
- Schweinebarth, Hannah, et al.
(författare)
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Lignin: evaluation of properties for applications
- 2015
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Ingår i: NWBC 2015. - Espoo : VTT. - 9789513883539 ; , s. 387-388
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Konferensbidrag (refereegranskat)abstract
- Utilization of abundant lignin-rich natural resources will provide new revenue streams for today’s kraft pulp mills. Owing to its phenol-rich structure, Lignin is very versatile and has much potential for application in many areas, for example: as a foundation for bulk chemical production, for conversion to fuel products, a binder material, a fertilizer, anti-oxidant, as a precursor for carbon fibres and nanofibres and for activated carbons.
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| 8. |
- Sewring, Tor, et al.
(författare)
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Estimation of the deprotonation degree of phenolic groups on kraft lignin
- 2015
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Ingår i: NWBC 2015. - Espoo : VTT. - 9789513883539 ; , s. 442-449
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Konferensbidrag (refereegranskat)abstract
- Research has been undertaken into the deprotonation degree of the phenolic groups on softwood kraft lignin in black liquor. An attempt was made to mathematically model the ion concentration distributions around lignin fragments in black liquor by studying the possibility of using a modified Poisson-Boltzmann cell model and extending the validity of this model by extrapolating the valid ionic concentration range using the Pitzer method. The model has been utilised to predict the pH dependent deprotonation degree under various conditions that are relevant to the LignoBoost process. It has been demonstrated that the pH and temperature strongly affected the deprotonation degree of phenolic groups on kraft lignin. The effect of the molecular weight of lignin and a small increase in ionic strength on the deprotonation degree was very small in black liquor systems of high ionic strength. It was observed that the pH at the surface of lignin macromolecules was approximately the same in black liquor systems of high ionic strength.
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| 9. |
- Sewring, Tor, 1988, et al.
(författare)
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Estimation of the deprotonation degree of phenolic groups on kraft lignin
- 2015
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Ingår i: NWBC 2015 - 6th Nordic Wood Biorefinery Conference. - : VTT Technical Research Centre of Finland. - 9789513883539 ; , s. 442-449
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Konferensbidrag (refereegranskat)abstract
- Lignin is an abundant biomaterial, with potential as raw material feed stock for production of solid- and liquid fuels as well as phenolic components and carbon fibres. Lignin may be separated from various process streams in an integrated pulp production and wood-based biorefinery. Separation of Kraft lignin from black liquor can be made by the LignoBoost technology; it starts with precipitation of lignin by acidification of the black liquor and consequently protonation of the phenolic groups on lignin, in equilibrium with the surrounding liquid. The protonation degree of phenolic groups on kraft lignin has been identified as a key-property in controlling the precipitation yield. It has been investigated if the protonation degree of lignin in a black liquor system can be modelled using a modified Poisson-Boltzmann cell model which has been combined with the Pitzer method. It was found that the model gave reasonable results. Furthermore, the model indicated that the protonation degree is strongly dependent on the pH and temperature of the black liquor, however, the molecular weight of lignin has a minor influence and at the high ionic strength in black liquor a small change in ionic strength has only a very small influence on the protonation. Additionally, the predicted deprotonation degrees were compared with previously measured precipitation degrees at industrially relevant conditions.
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| 10. |
- Wetterling, Jonas, 1988, et al.
(författare)
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Local filtration properties of microcrystalline cellulose
- 2015
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Ingår i: 6th Nordic Wood Biorefinery Conference, NWBC 2015. - : VTT Technical Research Centre of Finland. - 9789513883539 ; , s. 295-300
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Konferensbidrag (refereegranskat)abstract
- One of the main challenges with obtaining energy-efficient solid-liquid separation in biorefineries is the formation of compressible filter cakes. In this study the effect of particle surface structure as well as particle surface charge on the local filtration behaviour of microcrystalline cellulose was investigated. The filtration kinetics was found to be affected by the particle surface structure as a rough particle surface increases the specific surface area subjected to drag forces. Similarly, it was found that the filtration kinetics was improved by a low particle surface charge as attractive particle interactions between particles/particle fragments results in a smaller specific surface area subjected to drag. However, filtration of microcrystalline cellulose may result in a rate limiting “skin layer” close to the filter media during conditions were the particle surface is charged and the attractive forces between particles as well as steric hindrance are insufficient to prevent a local collapse of the filter cake. This “skin layer” has a large influence on the required filtration time and/or filter area of the separation, and may not be detected without the use of local filtration properties.
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| 11. |
- Wojtasz, Joanna, et al.
(författare)
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Chemical pretreatment of wood chips : A comparative study of mild steam explosion and hot water extraction
- 2015
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Ingår i: 6th Nordic Wood Biorefinery Conference, NWBC 2015. - : VTT Technical Research Centre of Finland. - 9789513883539 ; , s. 341-347
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Konferensbidrag (refereegranskat)abstract
- Pretreatment of wood is a prerequisite for an efficient separation and utilization of its building blocks in future biorefinery concepts. Inherent recalcitrance of the cellulose-hemicellulose-lignin matrix of the cell wall poses huge challenges on separation of these components and implies usually a need for a broad set of methods targeting different components and providing as well chemical as morphological alterations. Mild steam explosion and hot water extraction are examples of typical pre-treatment methods enabling extraction of hemicelluloses and facilitating further processing of wood. Both are based on autohydrolysis of lignocellulosic material at high temperatures, but involve generally different conditions, the most prominent difference being a rapid disintegrating discharge employed in the steam explosion treatment, rendering morphological changes and altering structure accessibility compared to the physically less disruptive hot-water extraction. In this study we compare the key features of both of these methods and present that their effects on wood are somewhat non-uniform.
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