Simulation and Experimental Validation of Hydrogen Evolution Reaction using Titanium Carbide Supported, Platinum Doped Tetrahedral Amorphous Carbon Electrode

This work presented the use of commercial software COMSOL Multiphysics to simulate and solve the Volmer - Heyrovsky –Tafel mechanistic steps for hydrogen evolution reaction (HER). The first study will address the reliability of COMSOL to provide accurate and precise results for electrochemistry problem. The developed model is for classical cyclic voltammetry of redox reaction (E). In this study, mesh refinement with its consequent number of elements (noe), computation time (tcom), and current, I(t) was compared on the 1-dimension (1D), 2-dimension (2D) axisymmetric, and 3-dimension (3D) model. This study proved the software's consistency to produce less than 3% error between simulation and analytical results across all dimensions. By using a relative tolerance (rtol) value of 1×10-8 with very concentrated custom meshing, a 3D model yielded a result with an error of 2.5% compared to analytical solution. It has the drawback of taking 40 times longer to complete. A slight discrepancy between 2D axisymmetric and 3D simulation results on finest meshing recorded to have less than 3% difference due to CPU memory limit. The use of adaptive meshing on 2D axisymmetric and 3D model with coarse initial mesh reduces the error significantly by 32% and 50%, respectively. At the same time, the computation time, tcom increased by nearly ten times on the 2D axisymmetric model and five times on the 3D model. On the “finer” initial mesh, the simulation has reduced the error to near 0%. The rtol study shows that the value of 1×10-4 is adequate for 2D axisymmetric and 1×10-5 for both 1D and 3D. Further investigations on complex electrochemistry using this platform are well justified and highly recommended. Given the reliability of COMSOL presented in the first study, the second study implement similar approach to model the experiment by Glandut et. al (2015) on Titanium carbide (TiC) support, tetrahedral amorphous carbon doped platinum (taC:Pt) electrode for hydrogen evolution reaction. The developed model was tested for surface diffusion in 2D and surface diffusion with edge effect in 3D. The simulation results show that kinetic parameters permutation with surface diffusivity shows some increased in current output but was unable to achieve the current output obtained from the experiment. However, the introduction of edge effect on the side of taC:Pt on TiC support would significantly increase the current output with great coherency to the experimental result. The edge exhibits kinetic properties unlike both TiC or taC:Pt. The kinetic parameters were determined using the simulation and a dataset was found to show great coherency with the experimental result. Surface diffusion was rendered negligible because negligible compared to the high kinetic parameters on the edge in comparison to the TiC and taC:Pt surface

Computational Studies of Confined Submerge Fan to Circulate and Oxygenate Hypolimnetic Layer in Hydro Power Reservoirs

The oxygen level is deficient at the depth of the lakes or reservoirs due to thermal stratification. Due to deficient oxygen level at the bottom of thermal stratified lakes, the reduction reactions occur that form hydrogen sulphide, iron, phosphorous and other compounds which are harmful to the water quality, fish life as well as dam or reservoir structures and other species. Hypolimnetic aeration and oxygenation systems can be used for this purpose to prevent the formation of harmful substances. A prototype design of submerged fan will be used to penetrate at maximum depth of the lakes or reservoirs and find the velocity of the submerged fan through CFD simulations

Parametric study and CFD simulation of a heat-driven adsorber for an air-conditioning system employing activated carbon

Adsorption cooling systems powered by waste heat or solar heat can help to reduce the use of ozone depletion substances, such as chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs). In this research work, a CFD simulation works were conducted on a prototype adsorption air-conditioning system powered by waste heat that was successfully tested in laboratory. The aim is to measure the system performance of the adsorption cooling and verify the results with experimental works

Étude paramétrique et simulation d'électrodes en carbone tétraédrique (taC) supportées par du carbure de titane (TiC) pour les réactions d'évolution de l'hydrogène (HER)

Given the reliability of COMSOL a study model the experiment by Glandut et. al (2015) on Titanium carbide (TiC) support, tetrahedral amorphous carbon doped platinum (taC:Pt) electrode for hydrogen evolution reaction. The developed model was tested for surface diffusion in 2D and surface diffusion with edge effect in 3D. The simulation results show that kinetic parameters permutation with surface diffusivity shows some increased in current output but was unable to achieve the current output obtained from the experiment. However, the introduction of edge effect on the side of taC:Pt on TiC support would significantly increase the current output with great coherency to the experimental result. The edge exhibits kinetic properties unlike both TiC or taC:Pt. The kinetic parameters were determined using the simulation and a dataset was found to show great coherency with the experimental result. Surface diffusion was rendered useless because negligible compared to the extremely high kinetic parameters on the edge in comparison to the TiC and taC:Pt surface.Compte tenu de la fiabilité de COMSOL un modèle d'étude l'expérience de Glandut et. al (2015) sur support en carbure de titane (TiC), électrode en platine dopé au carbone amorphe tétraédrique (taC:Pt) pour la réaction de dégagement d'hydrogène. Le modèle développé a été testé pour la diffusion de surface en 2D et la diffusion de surface avec effet de bord en 3D. Les résultats de la simulation montrent que la permutation des paramètres cinétiques avec la diffusivité de surface montre une certaine augmentation de la sortie de courant mais n'a pas été en mesure d'atteindre la sortie de courant obtenue à partir de l'expérience. Cependant, l'introduction d'un effet de bord du côté de taC:Pt sur le support TiC augmenterait considérablement la sortie de courant avec une grande cohérence avec le résultat expérimental. Le bord présente des propriétés cinétiques contrairement à TiC ou taC:Pt. Les paramètres cinétiques ont été déterminés à l'aide de la simulation et un ensemble de données a été trouvé pour montrer une grande cohérence avec le résultat expérimental. La diffusion de surface a été rendue inutile en raison des paramètres cinétiques extrêmement élevés sur le bord par rapport à la surface TiC et taC:Pt

Étude paramétrique et simulation d'électrodes en carbone tétraédrique (taC) supportées par du carbure de titane (TiC) pour les réactions d'évolution de l'hydrogène (HER)

Given the reliability of COMSOL a study model the experiment by Glandut et. al (2015) on Titanium carbide (TiC) support, tetrahedral amorphous carbon doped platinum (taC:Pt) electrode for hydrogen evolution reaction. The developed model was tested for surface diffusion in 2D and surface diffusion with edge effect in 3D. The simulation results show that kinetic parameters permutation with surface diffusivity shows some increased in current output but was unable to achieve the current output obtained from the experiment. However, the introduction of edge effect on the side of taC:Pt on TiC support would significantly increase the current output with great coherency to the experimental result. The edge exhibits kinetic properties unlike both TiC or taC:Pt. The kinetic parameters were determined using the simulation and a dataset was found to show great coherency with the experimental result. Surface diffusion was rendered useless because negligible compared to the extremely high kinetic parameters on the edge in comparison to the TiC and taC:Pt surface.Compte tenu de la fiabilité de COMSOL un modèle d'étude l'expérience de Glandut et. al (2015) sur support en carbure de titane (TiC), électrode en platine dopé au carbone amorphe tétraédrique (taC:Pt) pour la réaction de dégagement d'hydrogène. Le modèle développé a été testé pour la diffusion de surface en 2D et la diffusion de surface avec effet de bord en 3D. Les résultats de la simulation montrent que la permutation des paramètres cinétiques avec la diffusivité de surface montre une certaine augmentation de la sortie de courant mais n'a pas été en mesure d'atteindre la sortie de courant obtenue à partir de l'expérience. Cependant, l'introduction d'un effet de bord du côté de taC:Pt sur le support TiC augmenterait considérablement la sortie de courant avec une grande cohérence avec le résultat expérimental. Le bord présente des propriétés cinétiques contrairement à TiC ou taC:Pt. Les paramètres cinétiques ont été déterminés à l'aide de la simulation et un ensemble de données a été trouvé pour montrer une grande cohérence avec le résultat expérimental. La diffusion de surface a été rendue inutile en raison des paramètres cinétiques extrêmement élevés sur le bord par rapport à la surface TiC et taC:Pt

Custom design of a hanging cooling water power generating system applied to a Sensitive cooling water discharge weir in a seaside power plant : A challenging energy scheme

In this study, an innovative design of hydro-electricity system was applied to an unconventional site in an attempt to generate electricity from the exhaust cooling water of a coal-fired power plant. Inspired by the idea of micro hydro, present study can be considered new in three aspects: design, resource and site. This system was hung at a cooling water discharge weir, where all sorts of civil work were prohibited and sea water was used as the cooling water. It was designed and fabricated in the university's mechanical workshop and transported to the site for installation. The system was then put into proof run for a three-month period and achieved some success. Due to safety reasons, on-site testing was prohibited by the power plant authority. Hence, most data was acquired from the proof run. The driving system efficiency was tested in the range of 25% and 45% experimentally while modeling results came close to experimental results. Payback period for the system is estimated to be about 4.23 years. Result obtained validates the feasibility of the overall design under the sensitive site application