School of Chemistry Physics Mechanical Engineering School of Mathematical Sciences Science Engineering Faculty, Dec 1, 2014
Modelling of food processing is complex because it involves sophisticated material and transport ... more Modelling of food processing is complex because it involves sophisticated material and transport phenomena. Most of the agricultural products such fruits and vegetables are hygroscopic porous media containing free water, bound water, gas and solid matrix. Considering all phase in modelling is still not developed. In this article, a comprehensive porous media model for drying has been developed considering bound water, free water separately, as well as water vapour and air. Free water transport was considered as diffusion, pressure driven and evaporation. Bound water assumed to be converted to free water due to concentration difference and also can diffuse. Binary diffusion between water vapour and air was considered. Since, the model is fundamental physics based it can be applied to any drying applications and other food processing where heat and mass transfer takes place in porous media with significant evaporation and other phase change.
School of Chemistry Physics Mechanical Engineering Centre For Tropical Crops and Biocommodities Institute For Future Environments Science Engineering Faculty, Mar 1, 2006
School of Chemistry Physics Mechanical Engineering School of Earth Environmental Biological Sciences Institute For Sustainable Resources Science Engineering Faculty, Sep 22, 2011
School of Chemistry Physics Mechanical Engineering Institute For Future Environments Science Engineering Faculty, Jun 2, 2000
Lanthanum Strontium Manganate (LSM) powders were synthesised by six different routes, namely soli... more Lanthanum Strontium Manganate (LSM) powders were synthesised by six different routes, namely solid state reaction, drip pyrolysis, citrate, sol-gel, carbonate and oxalate co-precipitation. The LSM samples, produced by firing to 10008C for 5 h were then characterised by way of XRD, TPD's of oxygen, TPR and catalytic activity for a simple oxidation reaction, that of carbon monoxide to carbon dioxide. It was found that although the six samples had similar compositions and surface areas they performed quite differently during catalytic characterisation. These observed differences correlated more closely to the mode of synthesis, than to the physical properties of the powders, or their impurity levels, indicating that the surface structures created by the different syntheses perform very differently under catalysis conditions. Co-precipitation and drip pyrolysis produced structures that were most efficient at facilitating oxidation type reactions. be pure, with a small average particle size and large
Zeolite N was produced from a variety of kaolinites and montmorillonites at low temperature (b 10... more Zeolite N was produced from a variety of kaolinites and montmorillonites at low temperature (b 100°C) in a constantly stirred reactor using potassic and potassic + sodic mother liquors with chloride or hydroxyl anions. Reactions were complete (N 95% product) in less than 20 h depending on initial batch composition and type of clay minerals. Zeolite N with 1.0 b Si/Al b 2.2 was produced under these conditions using KOH in the presence of KCl, NaCl, KCl + NaCl and KCl + NaOH. Zeolite N was also formed under high potassium molarities in the absence of KCl. Zeolite synthesis was more sensitive to water content and temperature when sodium was used in initial batch compositions. Syntheses of zeolite N by these methods were undertaken at bench, pilot and industrial scales.
School of Chemistry Physics Mechanical Engineering School of Mathematical Sciences Science Engineering Faculty, Dec 1, 2014
Modelling of food processing is complex because it involves sophisticated material and transport ... more Modelling of food processing is complex because it involves sophisticated material and transport phenomena. Most of the agricultural products such fruits and vegetables are hygroscopic porous media containing free water, bound water, gas and solid matrix. Considering all phase in modelling is still not developed. In this article, a comprehensive porous media model for drying has been developed considering bound water, free water separately, as well as water vapour and air. Free water transport was considered as diffusion, pressure driven and evaporation. Bound water assumed to be converted to free water due to concentration difference and also can diffuse. Binary diffusion between water vapour and air was considered. Since, the model is fundamental physics based it can be applied to any drying applications and other food processing where heat and mass transfer takes place in porous media with significant evaporation and other phase change.
School of Chemistry Physics Mechanical Engineering Centre For Tropical Crops and Biocommodities Institute For Future Environments Science Engineering Faculty, Mar 1, 2006
School of Chemistry Physics Mechanical Engineering School of Earth Environmental Biological Sciences Institute For Sustainable Resources Science Engineering Faculty, Sep 22, 2011
School of Chemistry Physics Mechanical Engineering Institute For Future Environments Science Engineering Faculty, Jun 2, 2000
Lanthanum Strontium Manganate (LSM) powders were synthesised by six different routes, namely soli... more Lanthanum Strontium Manganate (LSM) powders were synthesised by six different routes, namely solid state reaction, drip pyrolysis, citrate, sol-gel, carbonate and oxalate co-precipitation. The LSM samples, produced by firing to 10008C for 5 h were then characterised by way of XRD, TPD's of oxygen, TPR and catalytic activity for a simple oxidation reaction, that of carbon monoxide to carbon dioxide. It was found that although the six samples had similar compositions and surface areas they performed quite differently during catalytic characterisation. These observed differences correlated more closely to the mode of synthesis, than to the physical properties of the powders, or their impurity levels, indicating that the surface structures created by the different syntheses perform very differently under catalysis conditions. Co-precipitation and drip pyrolysis produced structures that were most efficient at facilitating oxidation type reactions. be pure, with a small average particle size and large
Zeolite N was produced from a variety of kaolinites and montmorillonites at low temperature (b 10... more Zeolite N was produced from a variety of kaolinites and montmorillonites at low temperature (b 100°C) in a constantly stirred reactor using potassic and potassic + sodic mother liquors with chloride or hydroxyl anions. Reactions were complete (N 95% product) in less than 20 h depending on initial batch composition and type of clay minerals. Zeolite N with 1.0 b Si/Al b 2.2 was produced under these conditions using KOH in the presence of KCl, NaCl, KCl + NaCl and KCl + NaOH. Zeolite N was also formed under high potassium molarities in the absence of KCl. Zeolite synthesis was more sensitive to water content and temperature when sodium was used in initial batch compositions. Syntheses of zeolite N by these methods were undertaken at bench, pilot and industrial scales.
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Papers by Graeme Millar