Search for dissertations about: "countercurrent"

Showing result 1 - 5 of 8 swedish dissertations containing the word countercurrent.

  2. 1. Countercurrent operation in the dilute-acid hydrolysis of cellulose for ethanol production

    Author : Pär Pettersson; Avdelningen för kemiteknik; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; model; lignocellulose; wood; cellulose; ethanol production; dilute-acid hydrolysis; countercurrent; Kemiteknik och kemisk teknologi; Chemical technology and engineering;

    Abstract : Fuel ethanol can be produced from lignocellulosic materials to replace gasoline and diesel. A crucial step in the production process is the hydrolysis (saccharification) of the material, which can be achieved with dilute acid at high temperature. Unfortunately, sugar is degraded under these severe conditions, and the sugar yield is generally low. READ MORE

  4. 2. Isotope enrichment by countercurrent electromigration in molten salts

    Author : Arnold Lundén; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES;

    Abstract : A series of isotope enrichments by electromigration in molten saltslias been carried out during the last, years. The running conditions aresummarized in table 1 and the enrichments achieved are given intables 2—13. Practical details such as the arrangement of the electricalcircuits and the construction of the separation columns are discussed. READ MORE

  5. 3. Modeling and Performance Analysis of Alternative Heat Exchangers for Heavy Vehicles

    Author : Wamei Lin; Värmeöverföring; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Countercurrent flow; Graphite foam; Heat exchanger; Thermal performance; Computational fluid dynamics;

    Abstract : Cross flow heat exchangers made from aluminum are common as radiators in vehicles. However, due to the increasing power requirement and the limited available space in vehicles, it is extremely difficult to increase the size of heat exchangers (HEXs) placed in the front of vehicles. READ MORE

  6. 4. Analysis of Degradation Products from Wood and Methods for Detoxification of Lignocellulose Hydrolysates

    Author : Per Persson; Centrum för analys och syntes; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; galactoglucomannan; mass spectrometry; liquid chromatography; sugar degradation; detoxification; fermentation inhibitors; lignocellulose hydrolysates; Ethanol production; softwood; Analytical chemistry; Analytisk kemi; countercurrent supercritical fluid extraction;

    Abstract : In order to produce fuel ethanol from lignocellulose, it is necessary to hydrolyse the sugar-containing constituents hemicellulose and cellulose. During acid hydrolysis, a number of compounds are formed or liberated in addition to the fermentable monomeric sugars. READ MORE

  7. 5. A numerical investigation of energy conversions in geophysical boundary layers

    Author : Patrik Andreasson; Luleå tekniska universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Vattenteknik; Water Resources Engineering;

    Abstract : The detailed energy conversions in turbulent geophysical boundary layers are examined and quantified. The governing transport equations are solved by utilizing turbulence modelling. Different turbulence closures have been adopted for the boundary layers examined. READ MORE