Search for dissertations about: "chemical degradation"

Showing result 1 - 5 of 655 swedish dissertations containing the words chemical degradation.

  2. 1. Carbohydrate degradation and dissolution during Kraft cooking : Modelling of kinetic results

    Author : Dan Johansson; Ulf Germgård; Pedro Fardim; Karlstads universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Kraft cooking; softwood; hardwood; cellulose; xylan; glucomannan; degradation; dissolution; Chemical engineering; Kemiteknik; Chemical Engineering; Kemiteknik;

    Abstract : Chemical pulp fibres from wood are commonly used in products associated with packaging as well as with printing and writing. The prevalent way of liberating fibres is by subjecting wood chips to Kraft cooking. This process has a history of almost 130 years and should be both well described and well established. READ MORE

  4. 2. Recycling of TiO2 Pigments from Waste Paint: Process Development, Surface Analysis, and Characterization

    Author : Mikael Karlsson; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Recycling; Recovery; Paint; Titanium dioxide; Waste.; Municipal solid waste handling; Pyrolysis; Pigment;

    Abstract : Pigments are commonly used in paint, plastic and paper products and titanium dioxide (TiO2), the most important white pigment, accounts for approximately 70 % of the total volume of all pigments used today. Minerals containing TiO2 are relatively abundant in the earth’s crust. READ MORE

  5. 3. A tandem Catalyst for hydrogenation of CO2 to light olefins — The role of the zeolite component

    Author : Wei Di; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Brønsted acid density; MTO reaction; CO2 hydrogenation; tandem catalysts; HCPs; methanol-intermediate; pre-coking; Al distribution; light olefins; SSZ-13 zeolite;

    Abstract : The catalytic conversion of waste CO2 into light olefins offers a sustainable pathway for green chemicals production in the future. Over a tandem catalyst with the bifunctional active sites for methanol synthesis (CTM) and methanol to olefins (MTO), CO2 can be efficiently converted via intermediate methanol into a mixture of light olefins (ethylene, propene, butene). READ MORE

  6. 4. Functionalized mesoporous carbons as non-precious metal fuel cell catalysts

    Author : Johanna Dombrovskis; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; electrocatalysis; oxygen reduction reaction; non-precious metal catalyst; mesoporous carbon; fuel cell; X-ray absorption spectroscopy;

    Abstract : Fuel cells allow for clean and efficient chemical to electrical energy conversion. However, their high price significantly limits the market viability of the technology. This is to a large part due to the high cost of the precious metals used in most fuel cell catalysts. READ MORE

  7. 5. Sintering of nickel catalysts in the presence of NH3/H2

    Author : Johan Lif; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; stabilisation; hydrogen; nickel; ammonia; alumina; sintering; DFT calculation; catalyst deactivation;

    Abstract : Supported metal catalysts are used in many important industrial processes, where amination of alcohols is one example. The exposure of the supported metal catalyst to reaction conditions results usually to a decrease in catalytic activity, by for instance thermal degradation. READ MORE