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Showing result 1 - 5 of 40 swedish dissertations matching the above criteria.

2. 1. Chemical Speciation of Sulfur and Metals in Biogas Reactors : Implications for Cobalt and Nickel Bio-uptake Processes

   Author : Sepehr Shakeri Yekta; Bo Svensson; Ulf Skyllberg; Åsa Danielsson; Charles Banks; Linköpings universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Biogas; Anaerobic digestion; Chemical speciation; bio-uptake; Sulfur; Iron; Cobalt; Nickel; Biogas; Anaerob nedbrytning; Kemisk speciering; Bio-upptag; Svavel; Järn; Kobolt; Nickel;

   Abstract : A balanced supply of micronutrients, including metals such as iron (Fe), cobalt (Co), and nickel (Ni), is required for the efficient and stable production of biogas. During biogas formation, the uptake of micronutrient metals by microorganisms is controlled by a complex network of biological and chemical reactions, in which reduced sulfur (S) compounds play a central role. READ MORE

4. 2. Deactivation of emission control catalysts for heavy-duty vehicles : Impact of biofuel and lube oil-derived contaminants

   Author : Sandra Dahlin; Lars Pettersson; Isabella Nova; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NH3-SCR; Cu-SSZ-13; V2O5-WO3 TiO2; catalyst deactivation; diesel oxidation catalyst; sulfur; phosphorus; biodiesel; heavy-duty; emission control; regeneration; alkali metals; NH3-SCR; Cu-SSZ-13; V2O5-WO3 TiO2; katalysatordeaktivering; dieseloxidationskatalysator; svavel; fosfor; biodiesel; tunga dieselmotorer; avgasrening; regenerering; alkalimetaller; Chemical Engineering; Kemiteknik;

   Abstract : Catalytic emission control is used to reduce the negative impact of pollutants from diesel exhausts on our health and on the environment. For a heavy-duty truck, such a system consists of a diesel oxidation catalyst (DOC), a diesel particulate filter (DPF), a selective catalytic reduction (SCR) catalyst, and an ammonia slip catalyst (ASC). READ MORE

5. 3. Slag/Metal Metallurgy in Iron and Steel Melts

   Author : Johan Ekengård; Pär Jönsson; Attila Dioszegi; Johan Björkvall; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; austenit; syreaktivitet; slagg; fördelning; primär dendrit; metalldroppar; lamellär grafit; svavel; kompaktgrafit; skänk; nodulär grafit; raffinering; Metallurgical process science; Metallurgisk processvetenskap;

   Abstract : In this work, the metal and slag phase mixing in three steps of a ladle refining operation of steel melts and for an oxygen balance during cooling of cast iron melts have been studied at two Swedish steel plants and at two Swedish cast iron foundries, respectively. In order to predict the oxygen activity in the steel bulk in equilibrium with the top slag as well as in metal droplets in the top slag in equilibrium with the top slag, three slag models were used. READ MORE

6. 4. Catalytic Conversion of Undesired Organic Compounds to Syngas in Biomass Gasification and Pyrolysis Applications

   Author : Pouya H. Moud; Klas Engvall; Klas J. Andersson; Roberto Lanza; Mats Ahmadi Götelid; Anker Degn Jensen; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; tar reforming; biomass gasification; Ni-based catalyst; potassium; sulfur; pyrolysis gas; bio-crude conditioning; gas conditioning; Fe-based catalyst; tjärreformering; biomassaförgasning; Ni-baserad katalysator; kalium; svavel; pyrolysgas; konditionering bio-råolja; gaskonditionering; Fe-baserad katalysator; Chemical Engineering; Kemiteknik;

   Abstract : Reliable energy supply is a major concern and crucial for development of the global society. To address the dependency on fossil fuel and the negative effects of this reliance on climate, there is a need for a transition to cleaner sources. An attractive solution for replacing fossil-based products is renewable substitutes produced from biomass. READ MORE

7. 5. Sulfur isotopes used as a tracer of acidification reversal, dispersion of acid mine drainage and sulfur dynamics in small and large catchments

   Author : Carl-Magnus Mörth; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Svavel;

   Abstract : .... READ MORE