Search for dissertations about: "Alkali treatment"

Showing result 1 - 5 of 57 swedish dissertations containing the words Alkali treatment.

  2. 1. Oxygen-Alkali Treatment of Kraft Pulp and Cellobiitol. Model Experiments and Applied Studies of Interest for Oxygen Bleaching

    Author : Bengt Järrehult; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; selectivity; pH-levels; copper; oxygen delignification; catalytic effects; iron; alkali; cellobiitol; magnesium; yield;

    Abstract : 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. READ MORE

  4. 2. Mercerization and Enzymatic Pretreatment of Cellulose in Dissolving Pulps

    Author : Heléne Almlöf Ambjörnsson; Ulf Germgård; Thomas Nilsson; Storker Moe; Karlstads universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; alkali; carboxymethyl cellulose; cellulose I; cellulose II; cellulose dissolution; degree of substitution; enzymatic treatment; filterability; gel formation; mercerization; multivariate analytical methods; NIR FT Raman spectroscopy; sodium hydroxide; zink oxide; Chemical Engineering; Kemiteknik;

    Abstract : 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. READ MORE

  5. 3. The adsorption of arsenic oxyacids to iron oxyhydroxide columns : including studies of weakly hydrated ions and molecules in aqueous solution

    Author : Johan Mähler; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES;

    Abstract : 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. READ MORE

  6. 4. PFB Air Gasification of Biomass, Investigation of Product Formation and Problematic Issues Related to Ammonia, Tar and Alkali

    Author : Nader Padban; Avdelningen för kemiteknik; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NH3 formation; agglomeration; thermal conversion; PNA; PAH; alkali; tar; Biomass; gasication; ammonia reduction; Chemical technology and engineering; Kemiteknik och kemisk teknologi;

    Abstract : 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. READ MORE

  7. 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

    Author : Anita Pettersson; Högskolan i Borås; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; phosphorus recovery; co-combustion; fluidised bed combustion; olivine; Biofuels; zeolites; fertiliser; extraction; refuse derived fuels; kaolin; alkali; sulphur; ash; municipal sewage sludge;

    Abstract : 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. READ MORE