| 1. |
|
|
| 2. |
- Arkell, Anders, et al.
(author)
-
Extraction of Lignin from Kraft Black Liquor by Membrane Filtration
- 2014
-
In: [Host publication title missing]. ; , s. 219-220
-
Conference paper (other academic/artistic)abstract
- Lignin from black liquor in the kraft pulping process is a potential raw material for production of renewable chemicals and fuels. However, an efficient extraction method for the lignin from the black liquor is needed. Therefore, two new processes have been designed, which both utilize membrane filtration for the isolation of lignin from the kraft black liquor. The first one includes precipitation and filtration for the production of a solid lignin, while the second involves a base-catalysed reaction and organic-solvent extraction for the production of a precursor for liquid fuels.
|
|
| 3. |
|
|
| 4. |
- Arkell, Anders, et al.
(author)
-
Production of bio-oil from lignin extracted from kraft black liquor by the Sunmembrane process
- 2014
-
In: Process Development Division 2014 - Core Programming Area at the 2014 AIChE Annual Meeting. - 9781510812703 ; , s. 102-104
-
Conference paper (peer-reviewed)abstract
- It is essential for the pulp and paper industry to utilize as much of the forest raw material as possible to achieve the sustainability goals and to increase the profit. The fibres that are liberated during the kraft pulping process are used for pulp production, while the rest of the components from the wood are mainly incinerated. Lignin is one major byproduct from the kraft pulping process. It has a high heating value, and has not a large market outside internal boiler fuels.
|
|
| 5. |
- Bosson, Emma, et al.
(author)
-
Exchange and pathways of deep and shallow groundwater in different climate and permafrost conditions using the Forsmark site, Sweden, as an example catchment
- 2013
-
In: Hydrogeology Journal. - : Springer Nature. - 1431-2174 .- 1435-0157. ; 21:1, s. 225-237
-
Journal article (peer-reviewed)abstract
- This study simulates and quantifies the exchange and the pathways of deep and shallow groundwater flow and solute transport under different climate and permafrost conditions, considering the example field case of the coastal Forsmark catchment in Sweden. A number of simulation scenarios for different climate and permafrost condition combinations have been performed with the three-dimensional groundwater flow and transport model MIKE SHE. Results show generally decreasing vertical groundwater flow with depth, and smaller vertical flow under permafrost conditions than under unfrozen conditions. Also the overall pattern of both the vertical and the horizontal groundwater flow, and the water exchange between the deep and shallow groundwater systems, change dramatically in the presence of permafrost relative to unfrozen conditions. However, although the vertical groundwater flow decreases significantly in the presence of permafrost, there is still an exchange of water between the unfrozen groundwater system below the permafrost and the shallow groundwater in the active layer, via taliks. ‘Through taliks’ tend to prevail in areas that constitute groundwater discharge zones under unfrozen conditions, which then mostly shift to net recharge zones (through taliks with net downward flow) under permafrost conditions.
|
|
| 6. |
- Fransson, Åsa, 1971, et al.
(author)
-
Hydromechanical characterization of fractures close to a tunnel opening: A case study
- 2012
-
In: ISRM International Symposium - EUROCK 2012.
-
Conference paper (peer-reviewed)abstract
- Important factors influencing the hydromechanical behavior of a fracture are in situ rock stresses (natural and induced) as well as hydraulic heads, fracture orientation, connectivity and fracture geometry, including their infillings. Particular attention is given to larger, water-conducting fractures that intersect or are close to a tunnel. For the Bentonite Rock Interaction Experiment (BRIE) at the Äspö Hard Rock Laboratory (HRL) in Sweden, the interaction between rock and bentonite in a deposition borehole is of particular interest. The BRIE experiment is being conducted at a depth of 420 meters in crystalline rock. This paper presents results from the initial identification, characterization and modeling of a small number of fractures close to the tunnel opening. So far, these fractures have been identified as the most important water-conducting fractures. In this identification and characterization exercise, core-drilled, vertical, three-meter deep investigation boreholes were made in the tunnel floor. Logging of natural hydraulic heads in boreholes and hydraulic tests, along with borehole and tunnel mapping in combination with modeling, indicate small deformations. This was also confirmed by deformation measurements performed in the boreholes. The description of the site will be further updated and revised and additional investigations into the link between stress history, fracture geometry and selection of fracture mechanical properties will be of particular interest.
|
|
| 7. |
|
|
| 8. |
|
|
| 9. |
|
|
| 10. |
- Kihlman, Martin, 1986-
(author)
-
Dissolution of cellulose for textile fibre applications
- 2012
-
Licentiate thesis (other academic/artistic)abstract
- This thesis forms part of a project with the objective of developing and implementing a novel, wood-based, process for the industrial production of cellulose textile fibres. This new process should not only be cost effective but also have far less environmental impact then current processes. Natural and man-made fibres are usually plagued with problems (e.g. economic and environmental) and are unsuitable in meeting growing demands. The focus of this thesis was therefore to investigate the dissolution of cellulose derived from various pulps in novel aqueous solvent systems. It was shown that cellulose could be dissolved in a NaOH/H2O solvent at low temperatures (<0°C) and that such an alkaline solvent can be improved regarding the solubility, stability and rheological properties of the cellulose dopes formed if different additives (salts or amphiphilic molecules) are used. The effect of different kinds of pretreatment (individually and combined) and the influence of pulp properties on cellulose accessibility and dissolution were also evaluated. These pretreatments affected, as expected, some characteristic properties of the pulps mainly by reducing the DP but also, for example, changing the composition of the carbohydrates. Not only did the pretreatment affect the solubility it also increased the stability of the cellulose dopes, resembling the effect of chemical additives to the NaOH system. According to multivariate data analysis it was established that, of the pulp properties analyzed, only the composition of carbohydrates and the DP had a significant influence on the solubility of the pulps used in this study. Finally, it was emphasized that the dissolution of cellulose pulps seemed to be controlled by a very complex interaction between both kinetic and thermodynamic parameters.
|
|
