The Experts below are selected from a list of 414 Experts worldwide ranked by ideXlab platform
Juan Adanez - One of the best experts on this subject based on the ideXlab platform.
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coupled drying and Devolatilisation of non spherical wet pine wood particles in fluidised beds
Journal of Analytical and Applied Pyrolysis, 2002Co-Authors: L F De Diego, F Garcialabiano, Alberto Abad, P Gayan, Juan AdanezAbstract:Release of volatiles of non-spherical pine wood particles was analysed by means of continuous measurements of the CO2 and O2 concentrations obtained after the complete combustion of the volatiles and from flame extinction times. The effect of the atmosphere used for Devolatilisation was tested. The volatiles' evolution was nearly identical using air or N2 as fluidising gas. The Devolatilisation times increased with increasing the equivalent particle diameter, but there was an important scattering in the results. The data dispersion greatly decreased when the shape factor of the wood particles was considered. The Devolatilisation times were fitted to a power-law relation replacing the particle diameter by the equivalent particle diameter multiplied by the shape factor. The effect of the moisture content was studied by analysis of the Devolatilisation Process of pine wood particles of the same size and different moisture contents (0–50%). As the moisture content of the wood particles increased the Devolatilisation rate of combustible volatiles decreased and was more uniform along the Devolatilisation time.
J J Pis - One of the best experts on this subject based on the ideXlab platform.
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a comparison of different methods for predicting coal Devolatilisation kinetics
Journal of Analytical and Applied Pyrolysis, 2001Co-Authors: Ana Arenillas, Fernando Rubiera, J J PisAbstract:Knowledge of the coal Devolatilisation rate is of great importance because it exerts a marked effect on the overall combustion behaviour. Different approaches can be used to obtain the kinetics of the complex Devolatilisation Process. The simplest are empirical and employ global kinetics, where the Arrhenius expression is used to correlate rates of mass loss with temperature. In this study a high volatile bituminous coal was devolatilised at four different heating rates in a thermogravimetric analyser (TG) linked to a mass spectrometer (MS). As a first approach, the Arrhenius kinetic parameters (k and A) were calculated from the experimental results, assuming a single step Process. Another approach is the distributed-activation energy model, which is more complex due to the assumption that Devolatilisation occurs through several first-order reactions, which occur simultaneously. Recent advances in the understanding of coal structure have led to more fundamental approaches for modelling Devolatilisation behaviour, such as network models. These are based on a physico-chemical description of coal structure. In the present study the FG–DVC (Functional Group–Depolymerisation, Vaporisation and Crosslinking) computer code was used as the network model and the FG–DVC predicted evolution of volatile compounds was compared with the experimental results. In addition, the predicted rate of mass loss from the FG–DVC model was used to obtain a third Devolatilisation kinetic approach. The three methods were compared and discussed, with the experimental results as a reference.
L F De Diego - One of the best experts on this subject based on the ideXlab platform.
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coupled drying and Devolatilisation of non spherical wet pine wood particles in fluidised beds
Journal of Analytical and Applied Pyrolysis, 2002Co-Authors: L F De Diego, F Garcialabiano, Alberto Abad, P Gayan, Juan AdanezAbstract:Release of volatiles of non-spherical pine wood particles was analysed by means of continuous measurements of the CO2 and O2 concentrations obtained after the complete combustion of the volatiles and from flame extinction times. The effect of the atmosphere used for Devolatilisation was tested. The volatiles' evolution was nearly identical using air or N2 as fluidising gas. The Devolatilisation times increased with increasing the equivalent particle diameter, but there was an important scattering in the results. The data dispersion greatly decreased when the shape factor of the wood particles was considered. The Devolatilisation times were fitted to a power-law relation replacing the particle diameter by the equivalent particle diameter multiplied by the shape factor. The effect of the moisture content was studied by analysis of the Devolatilisation Process of pine wood particles of the same size and different moisture contents (0–50%). As the moisture content of the wood particles increased the Devolatilisation rate of combustible volatiles decreased and was more uniform along the Devolatilisation time.
C D Rudd - One of the best experts on this subject based on the ideXlab platform.
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soft ionisation analysis of evolved gas for oxidative decomposition of an epoxy resin carbon fibre composite
Thermochimica Acta, 2007Co-Authors: Guozhan Jiang, Neil Bowering, K H Wong, S J Pickering, Gavin S Walker, C D RuddAbstract:Soft ionisation mass spectrometry was used to investigate the oxidative decomposition of an epoxy resin/carbon fibre composite using thermogravimetry (TG) coupled with mass spectrometry (MS). Through comparison between decomposition in air and in argon, it was recognized that the first step of the oxidative decomposition of the epoxy resins was similar to the decomposition in argon. During the Devolatilisation Process, the oxidative decomposition underwent a thermal decomposition leading to the formation of a large amount of volatile products which were subsequently oxidized into water and carbon dioxide. The gas produced in the thermal decomposition was not oxidized completely leaving some organic volatiles in the emissions. Using soft ionisation, the components of the evolved gases were identified by mass spectrometry.
Joaquin Rodriguez - One of the best experts on this subject based on the ideXlab platform.
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kinetics of Devolatilisation of forestry wastes from thermogravimetric analysis
Biomass & Bioenergy, 2004Co-Authors: Magin Lapuerta, J J Hernandez, Joaquin RodriguezAbstract:The great potential of Maritime pine (Pinus pinaster) wastes in the middle regions of Spain has motivated an increasing interest about the energy use of this material, either through combustion or gasification Processes. Samples of these biomass wastes have been analysed by thermogravimetry under both inert and oxidant atmospheres, from room temperature up to , at different heating rates: 10, 30, 40, 50 and . An estimation of the proximate analysis of the samples was made from combination of both resulting weight loss curves. The Devolatilisation Process of the samples was divided into three non-interacting mass-loss events described as parallel first-order reactions, being the first event identified as the moisture loss Process, the second one as the hemicellulose and cellulose decomposition Process and the third one as that of lignin decomposition. A fitting algorithm to obtain the kinetic parameters permitted a good agreement with experimental results, as well as a good discrimination of the effect of the heating rate. Due to the non-homogeneous nature of the tested samples, the use of other conventional methods for obtaining the kinetic parameters has been proved to be inadequate.