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Showing result 21 - 25 of 1348 swedish dissertations matching the above criteria.

  2. 21. Kraft lignin valorization by hydrotreatment over Mo-based sulfided catalysts

    Author : Muhammad Abdus Salam; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Char; Bio-oil; Kraft Lignin; Hydrodeoxygenation; Y-zeolite; Metal sulfide; Depolymerization; Acidity;

    Abstract : The production of green fuels and chemicals from bio-based feedstock can suppress the dependency on fossil resources and help mitigate global climate challenges. Kraft lignin is a thermochemically modified natural lignin obtained from the pulping process as a byproduct. READ MORE

  4. 22. Partial methane oxidation from electronic structure calculations

    Author : Adam Arvidsson; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; ZSM-5 zeolite; density functional theory; microkinetic modelling; Mo6S8 cluster; partial methane oxidation;

    Abstract : Investigating catalytic reactions with computational methods is a powerful approach to understand fundamental aspects of catalytic reactions and find ways to guide catalytic design. Partial methane oxidation is one example of a reaction with intriguing challenges, where a detailed atomistic approach may help to unravel the bottlenecks of this, as of yet, inefficient reaction. READ MORE

  5. 23. Chemical modification of cellulose-new possibilities of some classical routes

    Author : Merima Hasani; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Cellulose esters; Cellulose characterization; Cellulose ethers; Cationization; Cellulose nanocrystals; Crosslinking of cellulose;

    Abstract : Owning to its unique structure, along with the inexhaustible renewability, cellulose has been a subject of scientific and commercial interest for over 150 years. However, given attractive structural properties, such as stiffness, hydrophilicity, stereoregularity, potential for chemical modifications and ability to form superstructures, utilization of this biopolymer is far below its potential. READ MORE

  6. 24. Simulation of Chemical Reactors

    Author : Tommy Hertzberg; Avdelningen för kemiteknik; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; fluid flow; chemical reactors; formox; fractional step; catalytic combustion; Spectral methods; self-adjoint operator; Chemical technology and engineering; Kemiteknik och kemisk teknologi;

    Abstract : This thesis consists basically of two parts. They are, however, interrelated by the fact that both parts concerns modelling of catalytic reaction systems and also by the fact that in both parts, spectral methods are used for simulation. The first part describes the numerical treatment of the dispersion model. READ MORE

  7. 25. The initial phase of the sodium bisulfite pulping of softwood dissolving pulp

    Author : Raghu Deshpande; Ulf Germgård; Martin Ragnar; Karlstads universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Activation energy; bisulfite pulping; cellulose; delignification; extractives; glucomannan; hemicelluloses; lignin; pine; spruce; thiosulfate; total SO2; xylan; Chemical Engineering; Kemiteknik;

    Abstract : The sulfite pulping process is today practised in only a small number of pulp mills around the globe and the number of sulfite mills that use sodium as the base (cation) is less than five. However, due to the increasing interest in the wood based biorefinery concept, the benefits of sulfite pulping and especially the sodium based variety, has recently gained a lot of interest. READ MORE