Sökning: "Alkali treatment"
Visar resultat 1 - 5 av 57 avhandlingar innehållade orden Alkali treatment.
1. Oxygen-Alkali Treatment of Kraft Pulp and Cellobiitol. Model Experiments and Applied Studies of Interest for Oxygen Bleaching
Sammanfattning : During oxygen delignification of kraft pulp the alkalinity has a decisive influence upon the selectivity, defined as viscosity at a given kappa number. Using 0.2% pulp consistency in order to achieve constant pH-levels a minimum selectivity was reached at pH 13, corresponding to 0.1 M NaOH. LÄS MER
2. Mercerization and Enzymatic Pretreatment of Cellulose in Dissolving Pulps
Sammanfattning : This thesis deals with the preparation of chemically and/or enzymatically modified cellulose. This modification can be either irreversible or reversible. Irreversible modification is used to prepare cellulose derivatives as end products, whereas reversible modification is used to enhance solubility in the preparation of regenerated cellulose. LÄS MER
3. The adsorption of arsenic oxyacids to iron oxyhydroxide columns : including studies of weakly hydrated ions and molecules in aqueous solution
Sammanfattning : The fundamental side of this project includes determination of ionic radii and plausible hydration numbers for the weakly hydrated alkali metal ions in solution, as well as an investigation of the intramolecular bond lengths of arsenic oxyacid species and orthotelluric acid. Experimental methods such as EXAFS, XANES and LAXS have been used for these purposes, as well as thorough screening for relevant structures in crystal structure databases. LÄS MER
4. PFB Air Gasification of Biomass, Investigation of Product Formation and Problematic Issues Related to Ammonia, Tar and Alkali
Sammanfattning : Fluidised bed thermal gasification of biomass is an effective route that results in 100 % conversion of the fuel. In contrast to chemical, enzymatic or anaerobic methods of biomass treatment, the thermal conversion leaves no contaminated residue after the process. LÄS MER
5. Characterisation of Fuels and Fly Ashes from Co-Combustion of Biofuels and Waste Fuels in a Fluidised Bed Boiler. A Phosphorus and Alkali Perspective
Sammanfattning : In the efforts to create sustainable production of heat and power and to reduce the net CO2 emissions to the atmosphere, alternative fuels are today being utilised. These fuels are, for example, biofuels and waste derived fuels such as different residues from the agricultural sector and the pulp and paper industry, municipal sewage sludge and municipal sorted solid waste. LÄS MER