Showing papers in "Fuel in 1985"

TL;DR: In this paper, a mathematical model of wood pyrolysis is presented that is in satisfactory agreement with experimental reaction product distributions over a range of conditions of practical importance for gasification and combustion.

TL;DR: In this article, diffuse reflectance Fourier transform infrared spectrometry was applied to reduce the widths of all bands in the spectra, and several bands absorbing between 3000 and 2800 cm−1 due to C-H stretching modes of alkyl groups in different environments couId be resolved.

TL;DR: In this article, the effect of coal rank on the gasification rate of coal char was examined and it was concluded that the surface active sites and/or the amount of exchangeable Ca and Na control the reactivity of low-rank coal chars in H2O.

TL;DR: In this article, an empirical approach was derived to describe the effects of the degree of carbon conversion on the reaction rate as a function of relevant test parameters (pressure range 1-70 bar, temperature 800-1000 °C).

TL;DR: The low-temperature oxidation of five coals, ranging in rank from subbituminous to anthracite, was studied in the temperature range 30 −250 °C, and the reaction kinetics were elucidated as discussed by the authors.

TL;DR: In this paper, a one-dimensional model was developed to describe the spontaneous heating process at relatively low temperatures of coal piles, and the model was applied to coal piles in coal fires.

TL;DR: In this article, the results from structural studies indicate the presence of a large number of aliphatic rings in the asphaltenes and resins from crude oils from the Orinoco basin.

TL;DR: In this paper, the reduction of nitric oxide during combustion of coal char in a fluidized-bed combustor was examined with respect to two reactions: a char-catalysed reaction and a charconsuming reaction.

TL;DR: In this paper, the porosity and pore size of vitrinite and inertinite macerals were measured by optical microscopy and quantitative measurements of porosity were made using image analysis.

TL;DR: In this article, the distribution of sodium in different sizes of fly ash produced during coal combustion provides useful insights into the vaporization and condensation mechanisms for sodium, and the departure of the concentration of sodium from an inverse square dependence on particle size can be used to infer the degree of sodium vaporization.

TL;DR: In this article, the apparent volatilization rate of wood rods undergoing fast pyrolysis by contact with a hot spinning steel disc was studied as a function of disc velocity, rod diameter, contact pressure and disc temperature.

TL;DR: In this article, samples of four types of wood and pure cellulose were pyrolysed under a stream of nitrogen in the thermobalance and in some of the Gray-King runs, using a modified retort.

TL;DR: In this article, changes in the macromolecular structure of a lignite and a bituminous coal during rapid pyrolysis in the temperature range 300-1200 K are described.

TL;DR: In this article, bitumen and bitumen-derived products were thermally cracked with and without sand at 360, 400 and 420 °C and the results showed that the activation energies for the reactions involved in cracking bitumen sand mixtures were lower than those involved in splitting bitumen alone.

TL;DR: In this article, the isosteric heat of adsorption of CH 4 indicated that the coal surface became more heterogeneous on carbonization, but the increase was not entirely associated with the increase in surface area.

TL;DR: In this paper, the main factors influencing reactivity of char originating from coal and lignite against different gasifying agents are reviewed, taking typical examples given in literature, the role of coal minerals, the effect of pyrolysis conditions, importance of the internal surfaces and their quality and accessibility are assessed.

TL;DR: In this paper, a detailed chemical study has been made on a suite of 27 Australian coals of varying rank, and it is proposed that brown coals consist of a polymeric lignin-based structure which traps varying amounts of smaller, more aliphatic, molecules.

TL;DR: In this paper, seven lignins from different sources were pyrolysed (i) isothermally in vacuum over the temperature range 300-1300 °C and (ii) at a constant heating rate of 30 °C min−1 and a pressure of 0.1 MPa.

TL;DR: In this paper, it is proposed that large thermally stable aromatic molecules can perform a similar role to the molecular entities present in the mobile phase of bituminous coals, and that the presence of hydroaromatic (hydrogen donor) species in the intermediate phase is unnecessary for the development of thermoplastic properties.

TL;DR: In this article, Dibenzyl ether in water at 374, 401 and 412 °C resulted in rapid ether hydrolysis to benzyl alcohol, which in turn underwent significant secondary reactions to polymeric material.

TL;DR: In this article, the reductive removal of nitric oxide from flue gases by reaction with polyacrylonitrile-based active carbon fibres (PAN-ACF) activated with sulphuric acid has been studied at 423-632 K, using a circulating flow reactor.

TL;DR: A coal product which exceeds the purity requirements for ash, iron and silicon in Hall Cell anode carbon was prepared by a unique leaching sequence involving caustic treatment, followed by treatments with sulphuric and nitric acids.

TL;DR: In this paper, the optical anisotropy of solvent-swollen and chemically derivatized thin sections of coal was examined for determining whether the coal is in a plastic or rubbery state, whether a rubber state is cross-linked and how mobile the macromolecular chain segments are.

TL;DR: In this article, 13 C CP/MAS n.m. spectroscopy was used to identify cellulose, hemicellulose, lignin, waxes and resins.

TL;DR: Low melting binary and ternary eutectics of the alkali metal halides, carbonates and sulphates have been found to be more effective low temperature catalysts for the CO2 and steam gasification of graphite and coal chars than the pure salt components as discussed by the authors.

TL;DR: In this article, the molecular weight distributions of coal tars and coal char extracts were examined in an effort to learn more about the process of mass transfer during coal pyrolysis.

TL;DR: In this paper, a microscopic method to characterize unburnt char particles in fly ash is proposed, and the char particles are classified into four types (vesicular, dense, mixed and mineral-rich) and categorized into five volumetric size classes (>106, 106−105, 105−104, 104−103, <103μm3).

TL;DR: In this paper, the characteristics of volatile matter evolution and the kinetics of thermal decomposition of British Kimmeridge Clay oil shale have been examined by thermogravimetry.

TL;DR: In this article, the chemical reactions which occur when Illinois No. 6 coal is subsequently oxidized at 100°C with O2 have been studied using in-situ FT-i.r. differende spectroscopy.

TL;DR: In this paper, the effects of atmosphere, pressure, heating rate and support material on the thermal reactions of bitumen were studied, and it was found that partial pressures of oxygen > 10% O2 favored exothermic oxidation reactions.