William Roy Jackson

An FTIR study of australian coals: Characterization of oxygen functional groups

Abstract The FTIR data in the oxygen-hydrogen stretching and carbonyl stretching regions for 28 Australian coals and their liquefaction products have been investigated. It was found that for the higher rank coals and asphaltenes, the absorbance at 3200 cm −1 correlates with the atomic O/C values and the acidic oxygen contents as measured by a non-aqueous titration technique. The technique of least-squares curve fitting was applied to deconvolute the carbonyl stretching region. The results showed that for the higher rank coals there were relationships between the amount of carbonyl functional groups present, as measured from the band areas, and the coal O/C values. Most brown coals with a high oxygen content (O/C > 0.26) contain less guest material and have a lower concentration of carbonyl groups both as acids and esters than brown coals with a lower oxygen content. They have a higher non-acidic oxygen content, principally as ethers.

Determination of the acid distribution and total acidity of low-rank coals and coal-derived materials by an improved barium exchange technique☆

The Schafer technique for the determination of acid distribution and total acidity of low-rank coals has been modified and improved to make the determinations quicker and cheaper without loss of accuracy. The acidity determinations have been extended to hydrophobic coal-derived materials by the addition of a trace of methanol (<0.3%, v/v) to the exchange medium.

Studies related to the structure and reactivity of coals: 14. Chemical characterization of a suite of Australian coals

Abstract A suite of Australian coals has been carefully selected to study how the chemical structure of a coal sample affects its reactivity under liquefaction conditions. Coals were selected on the basis of a diversity of carbon content (66 to 91%) and atomic H C ratios (0.5-1.7) but with consistently low sulphur (

Studies related to the structure and reactivity of coals: 15. Conversion characteristics of a suite of Australian coals

Abstract Australian coals of varying rank from a well characterized suite and with a wide range of atomic H C ratios have been reacted with hydrogen in tetralin at 405 °C both in the presence and absence of a tin promoter, and with both hydrogen and tin without solvent at 405 °C. The hydogenation activity correlates well with the atomic H C ratio of the coal. The effect of tin promoter is to increase conversion by a similar amount (13 ± 3%) across most of the range of coals, suggesting that similar functional groups are responsible for the reactivity of the macromolecular structure in both high and low rank coals. The coals have also been heated under nitrogen both in the presence and absence of decalin at 320 °C. The guest-host model used previously to successfully explain the reactivity of brown coals may also be applicable to selected higher rank coals. The structurally different semianthracite and algal coals at the two extremes of the H C ratio range (0.51 and 1.65, respectively) show contrasting reactivity patterns to the bulk of the coals studied.

An FTIR study of australian coals: A comparison of structural and hydroliquefaction data

Abstract A suite of 24 Australian coals ranging from semianthracite to brown coals, and the corresponding asphaltenes and residues resulting from hydroliquefaction studies have been characterized by the Fourier Transform Infrared technique. The spectral data in the carbon-hydrogen stretching region were used to determine aliphatic and aromatic contents of the samples. Information on the aliphatic and aromatic structures of coals was obtained by investigating the relationship of the aliphatic and aromatic hydrogen contents in coals and products to the coal H/C atomic ratio and to the liquefaction data. The results strongly support the guest-host structure for the brown coals. The variability in the structures observed for the higher rank coals supports the conclusion that such coals have a more complex macromolecular skeleton than the brown coals.

A Mitsunobu-based procedure for the preparation of alkyl and hindered aryl isocyanates from primary amines and carbon dioxide under mild conditions

Abstract A Mitsunobu-based procedure for the preparation of alkyl and hindered aryl isocyanates in excellent yields from primary amines and carbon dioxide under very mild conditions is described.

Hydrogenation of brown coal: IV Model compound studies and mechanistic considerations

Abstract A series of lignin-related phenyl, benzyl and alkyl ethers have been reacted with hydrogen in the presence of iron (II) acetate and tin metal as additives. Iron reduced the rate of reaction of the phenyl ethers and increased the rate of reaction of the benzyl and alkyl ethers compared to the reactions without additive. Tin decreased the rate of reaction of the phenyl and benzyl ethers and had no effect on the reaction of the alkyl ether. Neither iron nor tin changed the products from the reactions of the ethers compared to the reactions without additive. The results are discussed in terms of the use of iron and tin compounds as additives in coal liquefaction reactions.

Electrostatic immobilization of an olefin metathesis pre-catalyst on iron oxide magnetic particles

A quaternary ammonium Hoveyda-Grubbs olefin metathesis pre-catalyst has been reversibly immobilized on sulphonic acid-functionalised silica-coated iron oxide magnetic particles to affect ring closing metathesis with easy removal, reuse and regeneration.

Liquefaction studies of some Indonesian low rank coals

One sub-bituminous and five brown coals from South Banko and Kalimantan, Indonesia have been evaluated under a range of liquefaction conditions for the provision of liquid fuels. The coals were reacted with hydrogen using various catalysts in the presence and absence of a donor solvent, both with and without added sulfur-containing compounds. In addition, the coals have been reacted with CO/H2O in the presence and absence of an added alkali catalyst, sodium aluminate. The results confirm the effectiveness of Ni/Mo in the absence of added S, and Mo in the presence of S, as catalysts for solvent-free hydrogenation of low rank coals. The most interesting finding for the CO/H2O reactions was that Tanito Harum, a sub-bituminous coal, gave as high a conversion as any of the low rank coals.

Studies related to the structure and reactivity of coals: 19. Structure and reactivity of international coals based on hydrogen/tetralin reactions

A suite of coals from several continents has been characterized and reacted under conditions similar to those used by us for a suite of Australian coals. The reactivity of these coals with hydrogen in tetralin at 405 °C correlated well with the atomic HC ratios of the coals and the correlation curve was similar to that for Australian coals. Analyses of the products of these reactions by a diverse range of techniques has established that the structure of New Zealand brown coals can be described in terms of a host-guest model which was applicable to the closely related Australian brown coals. The product distributions from reactions of the higher rank coals also showed similarities to those for the Australian coals.