Prediction of Catalyst Bed Density and Simulation of Glycerol Steam Reformer for Hydrogen Production

The work focuses on mimicking the loading of the catalyst pellets into a reactor in a realistic manner and proposing a simple method to predict catalyst bed density using Blender 3D Software, a free and open-source 3D creation suite. The catalyst freely falling into a container was animated. The void fraction of loose and close-packing catalyst bed was compared. The effects of different catalyst shapes (sphere and cylinder) and sizes (2–5 mm) on the catalyst bed density in different reactor sizes (18-50 mm) were investigated. It could well predict the values with the error ranging from 0.36 to 6.59%. The obtained information from Blender was employed in a computational fluid dynamics (CFD) model for simulating hydrogen production in a glycerol steam reformer packed with Co-Ni/Al2O3 catalyst

Using e-learning to support international students' dissertation preparation

Purpose: A research paper on the design and implementation of an e-learning resource responding to the globalisation of education. The purpose of this paper is to focus on the challenges presented in learning and teaching on how to support international postgraduate (PG) students undertaking the specific task of a dissertation. Design/methodology/approach: Using findings from 250 PG students, 40 supervisors and two module tutors the research identified the content and language issues faced by students and recognised the need to design an enabler supporting the latter as independent learners and the academic staff delivering support. Findings: The e-learning tool provides an independent learning tool which addresses student concerns relating to the process and content of structuring a dissertation and the function of language. Initial responses have been positive from both staff and students in respect to providing a source of student support and feedback. Originality/value: The research shows how the Dissertation Game Model (DGM), evolved into an e-learning resource supporting student understanding of the content, structure, planning and writing of a dissertation. The e-learning tool focuses on helping international students understand what the generic contents of each chapter of a dissertation should contain and supports them in engaging in research as a transferable skill

Low-temperature co-sintering for fabrication of zirconia/ceria bi-layer electrolyte via tape casting using a Fe2O3 sintering aid

Bilayer electrolytes have potential in solid oxide cells to improve ionic conduction whilst blocking electronic conduction. GDC/YSZ bilayer electrolyte processinghas provenproblematic due to thermochemical instability at high sintering temperatures. We first match the shrinkage profile of the two bulk materials using a Fe2O3 sintering additive. Additions of 5 mol% of Fe2O3 in the GDC layer and 2 mol% of Fe2O3 in the YSZ layer prevents delamination during co-sintering. The addition of Fe2O3 promotes densification, enabling achievement of a dense bilayer at a reduced sintering temperature of 1300 ◦C; ∼150 ◦C below conventional sintering temperatures. Elemental analysis showed the compositional distribution curves across the bilayer interface to be asymmetric when Fe2O3 is employed. The Fe2O3 increases the total conductivity of the bilayer electrolyte by an order of magnitude; this is explained by the effect of Fe2O3 on reducing the resistive solid solution interlayer at YSZ/GDC interface from ∼15 to ∼5 m

The impact of sulphur on Ni-based anodes for solid oxide fuel cells

The research aims to explore the impact of sulphur on the Ni-based anodes used in solid oxide fuel cells (SOFCs). The work combines thermodynamic calculation, electrochemical measurements, anode microstructure analysis, and in-situ Raman techniques, to explore the interaction of hydrogen sulphide with nickel based anodes under SOFC operating conditions. Thermodynamic calculations have been made to predict the stability of SOFC·anode materials (Ni, Ceria, Zirconia) when exposed to hydrogen sulphide (H2S) in hydrogen/steam mixtures over a range of partial pressures of sulphur (pS2) and oxygen (p02) representative of fuel cell operating conditions. Measurements on a single fuel cells and anode half cells have been carried· out to study the effect of operating conditions (pH2S, pH2 • pH20, temperature) on the degree and nature of sulphur interaction with the anodes, correlating this with the thermodynamic predictions and microstructural analysis. Microstructural analysis used scanning electron microscopy on anode cermets, supported by work on Ni pellets, to explore anode surface structure alteration under the same test conditions as those used for electrochemical measurement. This allowed changes in anode microstructure induced by sulphur to be coupled to changes in anode electrochemical performance. Both ex-situ and in-situ Raman spectroscopy was also used to detect chemical species formed on the anode surface when exposed to sulphur. The work shows a correlation between electrochemical response and thermodynamic calculation. Nickel and ceria show differing behaviour depending on pH2S, pH2, pH20, or temperature. The impedance response of Ni anodes in hydrogen SUlphide atmospheres also shows a link with anode microstructure. Electrodes with relatively lower initial performance degraded at lower H2S concentrations than those with higher initial performance suggesting that the detrimental effect of sulphur on the anode is dominated by its interaction with three phase boundaries. Anode surface alteration induced by sulphur such as 'faceting' on Ni, and Ni agglomeration, was also observed and correlated with the impedance response. Raman spectroscopy offers promise as a probe to monitor surface electrolyte temperature as well as sulphur species on the nickel species.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Effect of impurity on thermally self-sustained double reactor coupling hydrogen production from glycerol reforming and methanol production from carbon dioxide and hydrogen

Thermally self-sustained double reactor (TSSDR) operating without external heat source consists of dual channels for endothermic and exothermic reactions. Hydrogen (H2) is produced from wasted glycerol by aqueous-phase glycerol reforming (APGR) at 200-250 ºC and 20-25 bar while carbon dioxide (CO2) is a by-product. Produced H2 and CO2 are used as raw materials for methanol synthesis (MS) at 200-250 ºC and 50-80 bar. Methanol synthesis and glycerol reforming occur at inner and outer channels of TSSDR, respectively. The TSSDR is fully packed with catalyst. Generated heat of exothermic reaction is sufficient for endothermic reaction. Main products of glycerol reforming in gas phase are H2 and CO2 while CO and CH4 are by-products. All products in gas phase are totally recycled as a feed stream for exothermic channel. CO and CH4 in feed reduce CO2 conversion and methanol yield in MS. The effect of impurities in glycerol feed stream also influences with hydrogen production in APGR. Especially, methanol, which is an impurity in glycerol feed obtained from biodiesel production, significantly reduces glycerol conversion in TSSDR

Effect of CuO as Sintering Additive in Scandium Cerium and Gadolinium-Doped Zirconia-Based Solid Oxide Electrolysis Cell for Steam Electrolysis

The effect of CuO as a sintering additive on the electrolyte of solid oxide electrolysis cells (SOECs) was investigated. 0.5 wt% CuO was added into Sc0.1Ce0.05Gd0.05Zr0.89O2 (SCGZ) electrolyte as a sintering additive. An electrolyte-supported cell (Pt/SCGZ/Pt) was fabricated. Phase formation, relative density, and electrical conductivity were investigated. The cells were sintered at 1373 K to 1673 K for 4 h. The CuO significantly affected the sinterability of SCGZ. The SCGZ with 0.5 wt% CuO achieved 95% relative density at 1573 K while the SCGZ without CuO could not be densified even at 1673 K. Phase transformation and impurity after CuO addition were not detected from XRD patterns. Electrochemical performance was evaluated at the operating temperature from 873 K to 1173 K under steam to hydrogen ratio at 70:30. Adding 0.5 wt% CuO insignificantly affected the electrochemical performance of the cell. Activation energy of conduction (Ea) was 72.34 kJ mol−1 and 74.93 kJ mol−1 for SCGZ and SCGZ with CuO, respectively