Sökning: "catalytic degradation"

Visar resultat 1 - 5 av 92 avhandlingar innehållade orden catalytic degradation.

  1. 1. Environmentally Degradable Polyethylene : Effects of Additives and Environment on the Degradation and Degradation products

    Författare :Farideh Khabbaz; KTH; []
    Nyckelord :LDPE; polyethylene; oxidative degradation; photo-oxidation; thermo-oxidation; degradation products; photosensitisers; pro-oxidant; starch; master-batch; gas chromatography mass-spectrometry; GC-MS; solid phase microextraction; SPME;

    Sammanfattning : This thesis summarises and compares the influences ofdifferent additives (photosensitisers, pro-oxidants, abiodegradable filler) on blown low-density polyethylene (LDPE)films during photo- and thermal degradation with respect tochemical changes in the polymer matrices and identifieddegradation products. Additives studied were irondimethyldithiocarbamate (FeDMC), nickel dibutyldithocarbamate(NiDBC), carbon black, starch, a pro-oxidant that consisted ofmanganese stearate together with styrene butadiene rubber (SBR)or natural rubber (NR) and a master batch containing linearLDPE, starch and pro-oxidant. LÄS MER

  3. 2. A Study of Biomass Combustion Problems and the Selective Catalytic Oxidation of Ammonia

    Författare :Göran Olofsson; Kemiska institutionen; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Chemical technology and engineering; Kemiteknik och kemisk teknologi; Energy research; Reaction mechanism; Ammonia degradation; Pt CuO Al2O3 Catalysts; SCO; Selective Catalytic Oxidation; Catalytic hot gas cleaning; Bed agglomeration; NOx emissions; Fluidised bed; Biomass combustion; Biogas; Energiforskning;

    Sammanfattning : Increasing awareness of the need of reducing CO2, NOx and SOx emissions from combustion systems has led to a strong interest in biomass as a fuel source. Using it in combination with fluidised bed combustion technology can lead to a lowering of NOx emissions to the atmosphere. LÄS MER

  4. 3. The Formation and Breakdown of Passive Film on Ni Alloys : in situ synchrotron studies

    Författare :Alfred Larsson; NanoLund: Centre for Nanoscience; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Passivity; Corrosion; Degradation; Nickel alloys; synchrotron; in situ; Fysicumarkivet A:2023:Larsson;

    Sammanfattning : Corrosion results in huge annual costs and a large environmental footprint. The corrosion rate of some alloys can be made negligible by the presence of a spontaneously forming oxide film on the surface, a so-called passive film. Famous examples of alloys exhibiting passivity are stainless steels. LÄS MER

  5. 4. LIGNIN DEPOLYMERISATION IN NEAR- CRITICAL WATER TO PRODUCE BIOFUEL AND CHEMICALS: EFFECT OF CO-SOLVENT AND pH

    Författare :Tallal Belkheiri; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; green chemicals; biofuel; lignin; catalytic degradation; Biomass valorisation; hydrogen donor; base depolymerisation;

    Sammanfattning : Lignin is a complex three-dimensional amorphous polymer, which, along with cellulose and hemicellulose, forms a main component of biomass. Its main role is in giving strength, rigidity and resistance to degradation. From a chemistry perspective, lignin is an important source of aromatics. LÄS MER

  7. 5. Exploring and exploiting plant biomass degradation by Bacteroidetes

    Författare :Cathleen Kmezik; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; polysaccharide utilization locus; plant biomass degradation; carbohydrate esterases; multidomain enzymes; Bacteroidetes; PUL transfer; carbohydrate-active enzymes; xylan;

    Sammanfattning : Bacteroidetes bacteria have evolved to become excellent biomass degraders. They achieved this by applying carbohydrate-active enzymes (CAZymes) and organizing genes connected to the degradation of specific polysaccharides into discrete gene cassettes, so-called polysaccharide utilization loci (PULs). LÄS MER