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Visar resultat 21 - 25 av 1340 avhandlingar som matchar ovanstående sökkriterier.

1. 21. CO2 mitigation in advanced power cycles

   Författare :Jens Wolf; Jinyue Yan; Hongguang Jin; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Chemical engineering; chemical looping combusion; co2 capture; hydrogen production; trigeneration; co-generation; Kemiteknik; Chemical engineering; Kemiteknik;

   Sammanfattning : This thesis encompasses CO2 mitigation using three different processes: i) natural gas-fired combined cycle with chemical looping combustion (CLC), ii) trigeneration of electrical power, hydrogen and district heating with extended CLC, iii) steam-based gasification of biomass integrated in an advanced power cycle. In CLC, a solid oxygen carrier circulates between two fluidised-bed reactors and transports oxygen from the combustion air to the fuel; thus, the fuel is not mixed with air and an inherent CO2 separation occurs. LÄS MER

3. 22. Impact of root and mycorrhizal exudation on soil carbon fluxes : influence of elevated CO2 and metals

   Författare :Emma M. Johansson; Patrick van Hees; Bert Allard; Phil Ineson; Örebro universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; amino acids; 13C; carbon cycle; ectomycorrhiza; elevated CO2; exudation; DOC; LMWOA; metal stress; monosaccharides; oxalate; Pinus sylvestris; saprotrophic fungi; soil respiration; NATURAL SCIENCES; NATURVETENSKAP; Environmental chemistry; Miljökemi; Enviromental Science; Miljövetenskap;

   Sammanfattning : The thesis concerns the behavior of root and ectomycorrhizal (ECM) exudates. In particular, the dynamics of soluble low molecular weight (LMW) organic compounds such as organic acids (LMWOAs), amino acids, monosaccharides, and dissolved organic carbon (DOC) have been studied. LÄS MER

4. 23. The chemical nature of CO2 adsorption in zeolite A

   Författare :Przemyslaw Rzepka; Niklas Hedin; Webley Paul; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; CO2 adsorption; flue gas CO2 capture; biogas upgrading; zeolite |NaK|-A; physisorption; chemisorption; kinetic separation; in situ diffraction; synchrotron XRD; NPD; NMR; IR; Materials Chemistry; materialkemi;

   Sammanfattning : The climate changes are accelerated by increasing levels of carbon dioxide in the atmosphere connected to the fossil-fuel-based energy system. Substantial reforms of the system are needed immediately and could include the implementation of carbon capture and storage (CCS) technologies. LÄS MER

5. 24. Extraction and chromatography of bioactive compounds in complex samples using supercritical CO2 technology

   Författare :Said Alhamimi; Centrum för analys och syntes; []
   Nyckelord :Supercritical CO2; Chromatography; Extraction; Mass transfer; Solubility;

   Sammanfattning : Bioactive compounds found in plants have been of interest to man since ancient times. These compounds have the ability to modulate the metabolic processes in our bodies, which suggests that they may promote better health. Bioactive compounds vary in their chemical structure, polarity, stability and biological activity. LÄS MER

7. 25. System studies of different CO2 mitigation options in the oil refining industry: Post-combustion CO2 capture and biomass gasification

   Författare :Daniella Johansson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; process integration; post-combustion CO2 capture. CO2 capture and storage CCS ; GHG emissions; oil refining industry; CO2 emissions; Fischer-Tropsch FT ; biomass gasification; energy market scenarios;

   Sammanfattning : To reach the objective endorsed by the EU Council for reducing EU greenhouse gas (GHG) emissions by 80-90% compared to 1990 levels by 2050, extensive cuts are necessary in all sectors. The oil refining sector is a major energy user and thus a major GHG emitter. LÄS MER