Search for dissertations about: "ash composition"

Showing result 1 - 5 of 104 swedish dissertations containing the words ash composition.

  2. 1. Fuel conversion and ash formation interactions : a thermochemical study on lignocellulosic biomass

    Author : Anna Strandberg; Markus Broström; Rainer Backman; Christoffer Boman; Maria Zevenhoven; Umeå universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Char conversion; pyrolysis; devolatilization; ash transformation; biomass; fuel characterization; fuel composition; ash composition; silicate formation; carbonate formation; thermogravimetric analysis; micro-tomography;

    Abstract : Biomass is considered to be CO2 neutral, and to be able to reduce the dependency on fossil fuels the need for expanded and sustainable biomass feedstock is increasing. Ash-related problems are some of the most important aspects of this increasing use of new biomass assortments in thermal energy conversion systems. READ MORE

  4. 2. Co-firing animal waste, sludge, residue wood, peat and forest fuels in a 50MWth CFB boiler : ash transformation, availability and process improvements

    Author : Henrik Hagman; Dan Boström; Rainer Backman; Anders Nordin; Umeå universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Co-combustion; animal waste; peat; waste wood; forest residues; industrial sludge; limestone; CFB boiler; ash transformation; corrosion; erosion; ash and deposit characteristics; deposit buildup; boiler failures; availability; sulfation; boiler design; boiler conversion; waste derived fuels; large scale; Samförbränning; animaliskt avfall; torv; returträ; skogsbränsle; reningsslam; askomvandling; korrotion; erosion; ask- och beläggnings-karaktäristik; beläggningstillväxt; tillgänglighet; sulfatisering; panndesign; pannkonvertering; avfallsderiverade bränslen; storskalig;

    Abstract : The direct variable costs for heat and electricity production based on solid biomass fuel combustion is approximately 3-5 times lower than the costs in a fossil fuel-oil based boiler in Sweden. In addition waste derived biomass fuels are typically much cheaper than biomass not classified as waste. READ MORE

  5. 3. Formation and degradation of PCDD/F in waste incineration ashes

    Author : Lisa Lundin; Stellan Marklund; Mats Tysklind; James Mulholland; Umeå universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; MSW; fly ash; remediation; ash; PCDD; PCDF; formation; degradation; destruction; dechlorination; thermal treatment; Environmental chemistry; Miljökemi;

    Abstract : The disposal of combustible wastes by incineration is a controversial issue that is strongly debated by both scientists and environmental activists due to the resulting emissions of noxious compounds, including (inter alia) polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), heavy metals and acid gases like sulfur dioxide. Currently available air pollution control devices are capable of effectively cleaning flue gases, and PCDD/F emissions to air from modern municipal solid waste (MSW) incinerators are low. READ MORE

  6. 4. Tephra horizons in the North Atlantic region during the Early Holocene

    Author : Ewa Lind; Stefan Wastegård; Margareta Hansson; Britta Sannel; Victoria Smith; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Tephrochronology; geochemical composition; Saksunarvatn Ash; Vedde Ash; Fosen Tephra; Askja-S; palaeoclimate; Younger Dryas; Early Holocene; “XRF ITRAX”; sediment geochemistry; stable isotopes; Faroe Islands; Norway; Sweden; kvartärgeologi; Quaternary Geology;

    Abstract : Uncertainties about the rate and magnitude of future climate change have drawn attention to the climate variability following the Late Glacial-Early Holocene transition, c. 12-8 ka BP. READ MORE

  7. 5. Application of fuel design to mitigate ash-related problems during combustion of biomass

    Author : Anders Rebbling; Christoffer Boman; Dan Boström; Marcus Öhman; Nils Skoglund; Sonja Enestam; Umeå universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Thermochemical energy conversion; biomass; combustion; ash chemistry; fuel design; ash transformation reactions; renewable energy;

    Abstract : The energy supply of today is, through the use of fossil energy carriers,contributing to increased net emissions of greenhouse gases. This hasseveral negative effects on our environment and our climate. In order toreduce the impact of this, and possibly to reverse some of the effects, allrenewable energy sources must be used. READ MORE