Structural characterisation of Middle Jurassic, high-volatile bituminous Walloon Subgroup coals and correlation with the coal seam gas content
- Authors: Chaffee, Alan , Lay, Galinda , Marshall, Marc , Jackson, William , Fei, Yi , Verheyen, Vincent , Cassidy, Peter , Scott, Steven
- Date: 2010
- Type: Text , Journal article
- Relation: Fuel Vol. 89, no. 11 (2010), p. 3241-3249
- Full Text: false
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- Description: The structure of a suite of high-volatile, bituminous Surat Basin, Queensland coals has been investigated by a combination of analytical probes. These included elemental analyses, pyrolysis-gas chromatography-mass spectroscopy and Fourier transform infrared spectroscopy, together with a study of their liquefaction products in both tetralin and solvent free-tin catalysed hydrogenations. Samples were gathered across a 300 m depth interval intersected by the sampling well. Most techniques revealed clear but subtle differences in structure as a function of depth. The oils produced by solvent free-tin catalysed hydrogenation, however, showed very distinct dependence with depth and the waxy content, as indicated by 1H-NMR, could be correlated with the coal seam gas content
MTE water remediation using Loy Yang brown coal as a filter bed adsorbent
- Authors: Butler, Craig , Green, Alison , Chaffee, Alan
- Date: 2008
- Type: Text , Journal article
- Relation: Fuel Vol. 87, no. 6 (2008), p. 894-904
- Full Text: false
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- Description: The future development of a non-evaporative brown coal dewatering technique called Mechanical Thermal Expression (MTE) will produce large volumes of acidic, salty and organic rich product water. The overall viability of the MTE process will, in turn rely on the availability of a simple and energy-efficient water remediation strategy. Water treatment using the feed coal itself as an adsorbent may provide such an option. In this study a fixed-bed configuration of raw Loy Yang coal was employed. When the adsorbent was first exposed to MTE water, most of the dissolved organic carbon (DOC) and most of the multivalent cations in solution were adsorbed. However, breakthrough of monovalent cations occurred after a volume of MTE water equivalent to just two times the volume of the adsorbent bed itself (2 bed volumes (BVs)) had passed, with only small proportions of Na and K being retained. About 60% (30 mg/g, db) of the dissolved organic carbon (DOC) and about 25% (0.16 mmol/g, db) of the total cations were removed after passing 20 BV of MTE water through the adsorbent bed. This corresponds to an adsorbent requirement that is 1.4% of the amount of coal to be dewatered. Thus, the use of brown coal adsorbent beds may be an effective primary water treatment option. However specific organic and inorganic components are likely to require further reduction prior to discharge to the environment
Coupled DEM-LBM simulation of internal fluidisation induced by a leaking pipe
- Authors: Cui, Xilin , Li, Jun , Chan, Andrew , Chapman, David
- Date: 2014
- Type: Text , Journal article
- Relation: Powder Technology Vol. 254, no. (2014), p. 299-306
- Full Text: false
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- Description: This paper presents a numerical study of soil fluidisation induced by local leakage from a buried pipe using the coupled discrete element and lattice Boltzmann approach (DEM–LBM). The behaviour of the system is studied using different flow rates and initial bed heights. The excess pore pressure distribution and the soil behaviour due to a localised leak are investigated and compared with previous experimental findings. The comparison indicates that DEM–LBM is capable of capturing the leakage–soil interaction at the particle scale. Moreover, as the flow distribution is found to be one-dimensional in the radial direction rather than one-dimensional in the vertical direction, an extension to the Ergun flow equation is derived and the numerically measured fluidising pressure shows good agreement with this analytical solution. In addition, as indicated by the numerical results and the derived analytical solution, the relationship between fluidising pressure and pipe buried depth as well as leak size is also established. The simulation results suggest that DEM–LBM is a promising tool to carry out further studies into the internal fluidisation phenomenon.
Dynamic modelling and optimisation of flexible operation in post-combustion CO2 capture plants - A review
- Authors: Bui, Mai , Gunawan, Indra , Verheyen, Vincent , Feron, Paul , Meuleman, Erik , Adeloju, Samuel
- Date: 2014
- Type: Text , Journal article , Review
- Relation: Computers and Chemical Engineering Vol. 61, no. (2014), p. 245-265
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- Description: The drive for efficiency improvements in post-combustion CO2 capture (PCC) technologies continues to grow, with recent attention being directed towards flexible operation of PCC plants. However, there is a lack of research into the effect of process disturbances when operating flexibly, justifying a need for validated dynamic models of the PCC process. This review critically examines the dynamic PCC process models developed to date and analyses the different approaches used, as well as the model complexity and their limitations. Dynamic process models coupled with economic analysis will play a crucial role in process control and optimisation. Also discussed are key areas that need to be addressed in future dynamic models, including the lack of reliable dynamic experimental data for their validation, development of feasible flexible operation and process control strategies, as well as process optimisation by integrating accurate process models with established economic analysis tools. © 2013 Elsevier Ltd.
Ambient temperature solubilisation of brown coal in ammonium carbamate ionic liquids
- Authors: Qi, Ying , Verheyen, Vincent , Vijayaraghavan, Ranganathan , MacFarlane, Douglas , Chaffee, Alan
- Date: 2016
- Type: Text , Journal article
- Relation: Fuel Vol. 166, no. (2016), p. 106-115
- Full Text: false
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- Description: Coal solubilisation is often a necessary step for the alternative utilisation of the cheap and abundant brown coal resources in the State of Victoria, Australia, such as producing high quality fuel or chemicals. A series of ionic liquids (ILs), ammonium carbamates, formed by the association of carbon dioxide (CO2) with low molecular weight secondary amines, were investigated as solvents for the solubilisation of Victorian brown coal. The ionic liquid was mixed with a Loy Yang coal at a mass ratio of 20 to 1 (dry basis) for 24 h at ambient temperature. The solubilisation yields of the coal using three such ILs from dimethyl-, diallyl- and dipropyl-amines, respectively, were between 18% and 23%. Repeated solubilisation of the coal with fresh solvent achieved higher yields, with the highest at 66% by the carbamate formed from dimethylamine (DIMCARB). The variations in chemical structure between the products were compared by elemental analysis and a variety of spectroscopic techniques (FTIR, Solid State 13C NMR and Py-GC-MS). The soluble products of the initial solubilisation were more aliphatic than their parent coal. The less polar ILs formed from diallyl- and dipropyl-amines (DACARB and DPCARB) appeared to be more selective for high molecular weight triterpenoids than DIMCARB. Subsequent treatment tended to dissolve more aromatic components. © 2015 Elsevier Ltd. All rights reserved.
An investigation of the generation of Acoustic Emission from the flow of particulate solids in pipelines
- Authors: Hii, N. , Tan, Chee Keong , Wilcox, Steven , Chong, Zyh
- Date: 2013
- Type: Text , Journal article
- Relation: Powder Technology Vol. 243, no. (2013), p. 120-129
- Full Text: false
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- Description: This paper is concerned with the generation of the Acoustic Emission (AE) from particulate flow and an investigation of the potential of implementing AE for flow parameters, namely the solid mass flow rate, particle velocity and size, monitoring. A series of experiments has been conducted to gather AE signals from a laboratory scale single flow-loop pneumatic conveying system. Initially, AE sensors were attached to two steel meshes which were placed with a fixed axial distance in the pipeline to study the generation of the AE and subsequently the possibility of using those generated AE to determine particle velocity in the pipeline. Particle velocities measured from this approach were compared with theoretical predictions. The results indicated that this approach could measure the mean particle velocity with reasonable accuracy. The generation of AE on five different sensor mounting locations was also studied. The results showed that sensors mounted on all those locations were able to respond to changes in the flow parameters. However, only two sensor locations (outer bend and Mesh) were chosen for further investigation. The final experimental results indicated that the AE features, namely Root-Mean-Square (RMS) and energy of the AE, are related to the changes in the flow parameters and good correlations were found. Good correlations between the RMS and energy of the AE with the momentum and kinetic energy of the particles, respectively, were also found. Overall, the studies indicated that features of AE have great potential in gas-solid two phase flow parameter monitoring. However, the studies also show that the applicability of the AE techniques to measure solid mass flow rates in practice would require tedious calibration. © 2013 Elsevier B.V.
Use of Secondary Ion Mass Spectrometry (SIMS) to identify fly ash mineral spatial and particulate distribution in epoxy polymer
- Authors: Ibraheem, Shahad , Devasahayam, Sheila , Standard, Owen , Bandyopadhyay, Sri
- Date: 2015
- Type: Text , Journal article
- Relation: International Journal of Mineral Processing Vol. 142, no. (2015), p. 139-146
- Full Text: false
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- Description: Fly ash from coal power stations consists typically of a series of oxide minerals. These minerals can have beneficial effects when used as reinforcement in a plastic matrix. In this work the advanced technique SIMS has been utilised to identify the spatial distribution of the various minerals in fly ash in an epoxy matrix with fly ash weights of 10% and 50%. It is observed that SIMS, which can scan normally to a precision of 0.5 to 0.05 wt.%, could positively identify the distribution of the fly ash mineral elements in the epoxy. Attempts were also made to identify the fly ash element distribution in the epoxy using a composition analysis method, namely, EDS. However, it is observed that in the present fly ash-epoxy composites, EDS could not identify the fly ash elements demonstrating SIMS is a much preferred identification technique than the popular EDS method. © 2015 Elsevier B.V. All rights reserved.
Modelling a biorefinery concept producing carbon fibre-polybutylene succinate composite foam
- Authors: Ghayur, Adeel , Verheyen, Vincent
- Date: 2019
- Type: Text , Journal article
- Relation: Chemical Engineering Science Vol. 209, no. (2019), p. 1-7
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- Description: In this study, a novel biorefinery concept producing carbon fibre-poly(butylene succinate) composite foam (CPC foam) from lignocellulose and CO 2 is modelled. The biodegradable nature of poly(butylene succinate) would allow for easy carbon fibre recovery from the CPC foam for reuse at the end of product lifecycle, thus allowing for a circular materials flow. Technical simulation results show the biorefinery consumes 417 kg of biomass, 33 kg of CO 2 , 86 kg of methanol, 23 kg of acetic anhydride, 130 kWh of electricity and 1166 kW of heat per hour. The facility generates 72 kg of CPC foam, 82 kg of carbon fibre, 24 kg of tetrahydrofuran and 50 kg of dimethyl ether (DME). DME is used to fulfil parasitic electricity requirement. These results demonstrate the technical viability of this biorefinery although, research is needed to reduce parasitic energy demand. This carbon negative biorefinery avoids carcinogens and halogens for polymeric materials synthesis by utilising green chemistry principles and lignocellulose feedstock.
Effect of reactant types (steam, CO2 and steam + CO2) on the gasification performance of coal using entrained flow gasifier
- Authors: Shahabuddin, M. , Bhattacharya, Sankar
- Date: 2021
- Type: Text , Journal article
- Relation: International Journal of Energy Research Vol. 45, no. 6 (2021), p. 9492-9501
- Full Text: false
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- Description: This study investigates the gasification behaviour of bituminous coal using different reactants of CO2, steam and a mixture of CO2 and steam under entrained flow gasification conditions at temperatures of 1000°C and 1200°C with atmospheric pressure. The major gas constituents of the syngas were measured using online micro-GC with a model number Varian 490, whereas the minor pollutant gases were analysed using Kitagawa gas detection tubes. A maximum carbon conversion of 86% was achieved under steam gasification at a temperature of 1200°C compared to 74% from CO2 gasification. The higher carbon conversion from steam gasification is due to the higher gasification reactivity than CO2 gasification. At 1000°C, the lower heating value (LHV) from steam gasification was determined to be 60%, 70% and 80% higher than that of CO2 gasification using the reactant concentrations of 10, 20 and 40 vol.%, respectively. Using a stoichiometric 50/50 ratio of CO2 and steam, the yield of H2, CO and CH4 were increased by 56%, 106% and 35% compared to that of pure CO2 gasification. At 1000°C, the LHV under mixed reactant condition is close to the LHV from the pure steam gasification at 1200°C. In steam gasification, increasing the temperature by 200°C from 1000°C decreases the LHV by 17 and 10% using 10 and 20 vol.% steam. The higher heating value from steam gasification is due to the H2 and CH4-rich syngas compared to CO-rich syngas in CO2 gasification. The BET surface area of the solid char from steam gasification is about 17 and two times higher than that of CO2 gasification at 1000°C and 1200°C, respectively. © 2021 John Wiley & Sons Ltd