Jazbec, M, Sendt, K & Haynes, BS 2004, 'Kinetic and thermodynamic analysis of the fate of sulphur compounds in gasification products', Fuel, vol. 83, no. 16, pp. 2133-2138.View/Download from: Publisher's site
Synthesis gas produced from gasification of coal contains sulphur compounds that need to be removed before the gas can be further processed. For the sulphur removal process, it is normally assumed that all sulphur is present as hydrogen sulphide (H2S) with minor amounts of carbonyl sulphide (OCS). This paper examines the equilibrium composition of a raw synthesis gas from a Texaco gasifier, and how the composition changes kinetically as the gas is cooled. It is confirmed that H2S should always be the dominant sulphur species in cold syngas, with about 5% of sulphur appearing as OCS. Higher temperatures, and very high cooling rates can cause significant conversion of the sulphur to elemental S2. © 2004 Elsevier Ltd. All rights reserved.
Lakota, A, Jazbec, M & Levec, J 2002, 'Impact of structured packing on bubble column mass transfer charasteristics. Part 2. Analysis of gas-liquid mass transfer measurements', Acta Chimica Slovenica, vol. 49, no. 3, pp. 587-604.
The impact of the Sulzer SMV 16 packing elements on mass transfer characteristics in a packed column was studied. The gas phase (oxygen) and the liquid phase (tap water) passed the device in a concurrent upflow mode. The measurements of physical absorption of the oxygen into the liquid were taken in both hydrodynamic regimes, partly in the homogeneous and partly in the heterogeneous. Also, the experiments were doubled in an empty column for comparison. In the calculation of the volumetric gas-liquid mass transfer coefficients, kLa, axial dispersion model (ADM) and plug flow model (PFM) were tested. It is systematically shown, that ADM gives far more reliable interpretation of the recorded data than PFM. For both modifications of the column the gas velocity affects the mass transfer coefficients the most. Higher values of kLa were found in the packed bed, and the impact of internals increases progressively with the gas velocity. For an empty column the correlation of Akita and Joshida5 gives the coefficients close to ours within 18.5%.
Lakota, A, Jazbec, M & Levee, J 2001, 'Impact of structured packing on bubble column mass transfer charasteristics: Part 1. Backmixing in the liquid phase', Acta Chimica Slovenica, vol. 48, no. 4, pp. 453-468.
Axial liquid phase dispersion coefficient in a concurrent up-flow bubble column packed with Sulzer structured packing (SMV 16) was measured by means of the stationary method in a region between the homogeneous and heterogeneous hydrodynamic regimes. Column had a 0.14 cm ID and 1.885 m total packing length. Tap water was used as liquid phase and oxygen as gas phase. KCl was used as a tracer. For comparison experiments were also performed in the same column but without packing. The gas holdup was determined simultaneously. An increase in the measured EL values with the gas velocity was observed in both packed and non-packed columns, while the liquid flow rate only slightly raised the axial dispersion coefficient when the column was packed. The presence of structured packing reduced the liquid axial dispersion coefficient for nearly 50 % at low gas velocities, whereas there was only 20 % reduction found at higher velocities.
Jazbec, M & Haynes, BS 2005, 'Kinetic study of methanol oxidation and the effect of NOx at low oxygen concentrations', 5th Asia-Pacific Conference on Combustion, ASPACC 2005: Celebrating Prof. Bob Bilger's 70th Birthday, pp. 245-248.
A detailed kinetic mechanism for methanol oxidation in not only important to model methanol as a fuel but also it is a key sub-mechanism in hydrocarbon combustion mechanisms. The current study focuses on the reaction of methanol (400 ppm CH3OH/N2) in the temperature range of 573-1023 K (with residence times of 2.3-4.2 s) and at atmospheric pressure. The reaction was performed in a laminar flow reactor with the addition of small concentrations of O2 (0-1500 ppm), thus providing a range of mostly fuel rich conditions, and was perturbed by the addition of NOX (0-200 ppm). The main products of the reaction are formaldehyde (CH2O), hydrogen (H2), carbon monoxide (CO), water (H2O) and carbon dioxide (CO2), and, in the presence of NOX, nitrogen oxide (NO) and nitrogen dioxide (NO2). Methanol reacts with O2 at temperatures above 923 K, but when NOX is added, the reaction temperature is lowered to 773 K. This paper presents experimental results in a range of oxygen conditions not studied before. The experimental data are also modelled with the kinetic mechanisms currently available in the literature.
Jazbec, M, Sendt, K & Haynes, BS 2003, 'Chemical kinetic analysis of the rate of the unimolecular initiation step in H2S thermolysis', COMBUSTION SCIENCE AND TECHNOLOGY IN ASIA-PACIFIC AREA: TODAY AND TOMORROW, 4th Asia-Pacific Conference on Combustion, SOUTHEAST UNIV PRESS, Southeast Univ, Nanjing, PEOPLES R CHINA, pp. 472-475.
Sendt, K, Jazbec, M & Haynes, BS 2002, 'Chemical kinetic modeling of the H/S system: H2S thermolysis and H-2 sulfidation', PROCEEDINGS OF THE COMBUSTION INSTITUTE, 29th International Combustion Symposium, COMBUSTION INST, HOKKAIDO UNIV, SAPPORO, JAPAN, pp. 2439-2446.View/Download from: Publisher's site
Sendt, K, Jazbec, M & Haynes, BS 2002, 'Chemical kinetic modeling of the H/S system: H2S thermolysis and H2 sulfidation', International Symposium on Combustion Abstracts of Accepted Papers, p. 75.
A detailed chemical mechanism was developed to describe reactions in the H2-S2-H2S system. The mechanism consisted 21 reactions among the species H2S, S2, H2, HSSH, HSS, SH, S, and H. The mechanism was validated against a diverse collection of published data for H2S thermolysis in a static cell or in flow reactors, at 873-1423 K; 0.04-3 bar; and H2S mole fractions of 0.02-1. The predictions of the mechanism were sensitive only on the rates of the processes responsible for S-S bond formation. Data for the reverse, hydrogen sulfidation reaction (H2 + S2) were also modeled very accurately. This comprehensive chemical kinetic mechanism for the H/S system describes a wide range of experimental data and provides the basis for the construction of accurate models for H2S oxidation in combustion and related systems. Original is an abstract.
Jazbec, M, Bromly, JH, Barnes, FJ & Haynes, BS 2002, 'The effect of NO on CH3OH oxidation', International Symposium on Combustion Abstracts of Works-in-Progress Posters, p. 247.
The experimental and modeling kinetic study of the low temperature CH3OH oxidation was presented. The experiments were performed at 1 atm isothermal plug-flow reactor at 400°-760°C and residence times 0.5-3 sec. Oxidation of 75-300 ppm CH3 OH with O2 (0-20%) was carried out with and without NO (0-650 ppm) present. The experimental results were modeled with a previously developed methane oxidation mechanism for lean fuels and low temperatures. Chemical-kinetic modeling was performed with the Sandia ChemkinII/Senkin chemical kinetic packages using plug flow reactor model. The addition of NO to identify the branching ratio of Rl was discussed and the chemistry of CH3OH reactions was revealed. Original is an abstract.
Dunstan, C, Alexander, D, Morris, T, Langham, E & Jazbec, M Institute for Sustainable Futures, UTS 2017, Demand Management Incentives Review: Creating a level playing field for network DM in the National Electricity Market, pp. 1-57.View/Download from: UTS OPUS
This review assesses and quantifies the financial barriers to DM created by existing economic regulatory incentives for distribution network businesses. the Australian Renewable Energy Agency (ARENA) commissioned ISF to conduct the review to support the Australian Energy Regulator (AER) in developing the new DM Incentive Scheme required by a change to the National Electricity Rules in 2015.
Jazbec, M & Haynes, BS 2000, Low temperature H2S oxidation in the presence of NOx, International Symposium on Combustion Abstracts of Accepted Papers, p. 382.
Trace amounts of H2S, which are present in natural gas, can be emitted in the atmosphere as H2S or in the oxidized form as SOx. The low-temperature oxidation of H2S was studied experimentally in an isothermal plug flow reactor at an interval of 150°-550°C and 1 atm and analyzed the interaction of 100 ppm H2S with 0-100 ppm NO, 0-100 ppm NO2 with or without O2 present (0-20%). NO and NOx concentrations were also determined using a chemiluminescent NOx analyzer. NO2 reacted readily with H2S in the absence of O2 even at 150°C. The products detected were H2O, SO2, NO, NO2, O2, and trace amounts of H2. In the presence of O2, SO2 was the main sulfur product. However, in the absence of O2, S2O formation occurred when H2S reacted with NO2.