No description available.

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No description available.

This work investigates the influence of one or more OH groups present on the fuel molecule and the resultant formation of NOX emissions. Combustion of oxygenated fuels has been increasing globally and such fuels offer significant potential in the reduction of pollutant emissions. One such emission class is the oxides of nitrogen, which typically form through a combination of two regimes: the thermal and non-thermal mechanisms. While thermal NO formation can be reduced by lowering the combustion temperature, non-thermal NO formation is coupled to the fuel chemistry. An experimental and computational investigation of NOX formation in three different burner configurations and under a range of equivalence ratios and temperature regimes explored the differences in NO formation. Measurements of temperature profiles and in-flame species concentrations, utilizing both probed and non-intrusive laser based techniques, allowed for the investigation of NO formation through non-thermal pathways and the differences that exist between fuels with varying numbers of OH groups. The first burner configuration was composed of a high swirl liquid spray burner with insulted combustion chamber walls designed specifically for the combustion of low energy density fuels. In this system the combustion of alcohols and glycerol (the largest by-product of biodiesel production), along with other fuels with multiple hydroxyl groups, was studied. Measurements of the mean flame temperature and exhaust gas measurements of NOX showed significant reductions in non-thermal NO concentrations with increasing numbers of OH groups. An accompanying modeling study and detailed reaction path analysis showed that fuel decomposition pathways through formaldehyde were shown a preference due to the presence of the OH groups which resulted in reduced contributions to the hydrocarbon radical pools subsequent reductions to the Prompt NO mechanism. Two burner configurations with reduced dimensionality facilitated measurements in premixed flames for temperature and species in high and low temperature flames. These measurements included probed thermocouple temperature measurements, extractive gas sampling for NO and intermediate hydrocarbon species, and planar Laser Induced Fluorescence (LIF) measurements for 2OH-LIF thermometry, semiquantitative CH2O LIF, and quantitative NO LIF. Additionally, the simplified nature of the burner geometries allowed for the modeling of the flames incorporating detailed reaction kinetics for fuel decomposition and NOX formation. Significant reductions in NO formation were observed in comparisons of alcohol and alkane flames, resulting in up to 50% reductions in the pollutant. Computational analyses and nitrogen flux accounting allowed for the identification of the reduction in NO formation through all the known NOX formation pathways. It was observed that all of the known pathways exhibited reductions in contributions to NO formation in the presence of OH functional groups, indicating a complex coupling of fuel and NOX chemistry.

No description available.

The protic acid-catalyzed polymerization of 1,6-anhydro-6-D-glucopyranose (I) was first reported one-half century ago; however, the mechanism of this reaction has not been resolved and is the topic under investigation in this thesis. In an attempt to resolve this mechanism, a number of 1,6-anhydrides structurally related to 1,6-anhydro-B-D-glucopyranose (I) were prepared and polymerized. The C-2, C-3, or C-4 hydroxyl group was either specifically blocked, replaced by a hydrogen atom or positioned different sterically. The relative rates of disappearance of monomer in the polymerization reaction were measured and this information used to propose a reaction mechanism.

No description available.

Thesis (Ph. D.)--Institute of Paper Chemistry, 1942. / Includes bibliographical references (p. 106-107).

No description available.

Lignin är en restprodukt från massaindustrin som har stor potential för vidareanvändning i bland annat materialutveckling. För att utreda möjliga användningsområden för ett specifikt lignin är det viktigt att ha kunskap om ligninets molekylstruktur och bindningar. 31P-NMR spektroskopi kan användas som analysmetod för kvantifiering av hydroxylgrupperna hos lignin. Vid användning av 31P-NMR spektroskopi måste ligninprovet först derivatiseras med ett derivatiserings-reagens innehållande fosfor. Till analyserna behövs en lämplig intern standard för att kunna beräkna halten av de olika strukturelementen i lignin. RISE Research Institutes of Sweden ville se om det gick att komplettera analyserna av lignins struktur med hjälp av ett nytt derivatiserings-reagens, DR(I) (2-chloro-1,3,2-dioxaphospholane). Tidigare har derivatiserings-reagenset DR(II) (2-chloro-4,4,5,5-tetramethyl-1,3,2-dioxaphospholane) använts. Det nya derivatiserings-reagenset DR(I) har en liknande struktur men är en mindre molekyl och förväntades därför kunna analysera fler strukturelement som tidigare inte kunnat påvisas. Projektet har undersökt 10 olika interna standarder med DR(I) i syfte att hitta den bästa interna standarden. Den första som undersöktes är den som används med DR(II), N-hydroxy-5-norbornene-2,3-dicarboxylic acid imine. Av de undersökta interna standarderna är tre tagna från tidigare litteratur och sex är tidigare helt obeprövade. Samtliga undersöktes både som blankprov och med ett utvalt barrveds-kraftlignin. N-hydroxy-1,8-naftalimid (intern standard 4) var bäst baslinjeupplöst men inte tillräckligt stabil för att kunna användas som intern standard. Bisfenol-A (intern standard 3) var den interna standard som var den mest stabila och alla stabilitetstest utfördes med denna interna standard som referens. Av de tidigare obeprövade interna standarderna är det endast N-hydroxysuccinimide (intern standard 5) som kan användas som intern standard, dock är den inte tillräckligt stabil. N-hydroxy-5-norborene-2,3-dicarboxylic acid imine (intern standard 1) ansågs vara den bäst lämpade interna standarden. Denna prövades med olika typer av kraftlignin; barrveds-kraftlignin, lövveds-kraftlignin samt ett blandlignin. Den undersöktes även med ”milled wood lignin”. För detta lignin var det uppenbart att den valda interna standarden inte var helt optimal. En annan intern standard med bättre baslinjeupplösning skulle vara ett bättre alternativ för ”milled wood lignin”. Relaxationstiden mättes även för intern standard 1 och de olika strukturerna i ligninet. RISE Research Institutes of Sweden kan använda DR(I) som komplement till den nuvarande analysen med DR(II) vid beräkning av mängden av de sekundära alifatiska grupperna. En uppdelning av de olika formerna (erythro och threo) av den vanligaste bindningen hos lignin, β-O-4-bindningen, går också att urskilja. Eftersom denna bindning bryts i sulfatmassaprocessen är signalen svag, vilket gör att en uppdelning av erythro och threo vid beräkningarna av hydroxylgrupperna inte är relevant. / Lignin is a residue from the pulp industry, which has great potential for further use, including material development. To investigate possible uses for a specific lignin, it is important to have knowledge of the lignin's molecular structure. 31P NMR spectroscopy can be used when quantifying the hydroxyl groups of lignin. When using 31P NMR spectroscopy, the lignin sample must be derivatized with a phosphorous reagent. The analysis requires an appropriate internal standard to calculate the amount of the different structural elements in lignin. RISE Research Institutes of Sweden wishes to complement the analyzes of lignin structures using a new derivatization reagent, DR(I) (2-chloro-1,3,2-dioxaphospholane). Previously, the derivatization reagent DR(II) (2-chloro-4,4,5,5-tetramethyl-1,3,2-dioxaphospholane) has been used. The new derivatization reagent DR(I) has a similar structure but is a smaller molecule. In this report, 10 different internal standards have been examined with DR(I) to find the most suitable one. The first internal standard, N-hydroxy-5-norbornene-2,3-dicarboxylic acid imine, was used with DR(II). Three internal standards were from articles and six were previously unexamined. All of these were first tested as blanks without lignin and then with a selected softwood lignin. N-hydroxy-1,8-naphthalimide (internal standard 4) showed the best resolution but was not stable enough to be used as an internal standard. Bisphenol A (internal standard 3) was the most stable derivatized internal standard and the stability tests were performed with this internal standard as a reference. Of the previously unexamined internal standards, N-hydroxysuccinimide (internal standard 5) was the only appropriate internal standard to use. However, it was not as stable as N-hydroxy-5-norbornene-2,3-dicarboxylic acid imine (internal standard 1), which was found to be the most suitable internal standard. N-hydroxy-5-norbornene-2,3-dicarboxylic acid imine (internal standard 1) was examined with different types of kraft lignin; softwood kraft lignin, hardwood kraft lignin and a mixture kraft lignin. N-hydroxy-5-norbornene-2,3-dicarboxylic acid imine was also investigated with "milled wood lignin". For ”milled wood lignin” it became obvious that the resolution of the selected internal standard can be improved. Another internal standard that has not been examined in this report could be a better option. The relaxation time was also determined for N-hydroxy-5-norbornene-2,3-dicarboxylic acid imine and the different hydroxyl groups of lignin. RISE Research Institutes of Sweden can use DR(I) in analysis of kraft lignin as a complement to the currently used method with DR(II) for calculating the amount of secondary aliphatic groups. A differentiation of erythro and threo of the most common binding (β-O-4) can also be noted with these lignins with DR(I). Since this bond is broken to a large extent in the kraft process, the signal is week. This means that when calculating the hydroxyl groups, a separation of erythro and threo is not relevant.