Design and manufacture of reformer in polymer electrolyte membrane fuel cell

The paper describes the development and manufacturing aspects of the reformer in polymer electrolyte membrane (PEM) fuel cell, from the first step of realization that includes modelling the main parts of the reformer; analysing the reforming initial geometry, adopting changes in shape and dimensions caused by inaccessibility of tools during machining; and the manufacture of the reformer. Development and manufacturing are performed based on a model developed in SolidWorks (R). Based on this model, numerical analysis is performed in order to show the influence of geometry and its changes that affect reformer performance, and is not shown here. Adopted changes in the reformer design are presented, along with detailed explanation. Reformer processing is carried out on a milling machine and Wire EDM machine. The transversal hole diameter on the reformer is increased from 1 to 2 mm to reduce economic cost. Before processing, the tool path simulation is also performed. Beside the main subject, general data on proton exchange membrane fuel cell are introduced with a short description and explanations of the PEM function, method and purpose

Design and manufacture of reformer in polymer electrolyte membrane fuel cell

The paper describes the development and manufacturing aspects of the reformer in polymer electrolyte membrane (PEM) fuel cell, from the first step of realization that includes modelling the main parts of the reformer; analysing the reforming initial geometry, adopting changes in shape and dimensions caused by inaccessibility of tools during machining; and the manufacture of the reformer. Development and manufacturing are performed based on a model developed in SolidWorks (R). Based on this model, numerical analysis is performed in order to show the influence of geometry and its changes that affect reformer performance, and is not shown here. Adopted changes in the reformer design are presented, along with detailed explanation. Reformer processing is carried out on a milling machine and Wire EDM machine. The transversal hole diameter on the reformer is increased from 1 to 2 mm to reduce economic cost. Before processing, the tool path simulation is also performed. Beside the main subject, general data on proton exchange membrane fuel cell are introduced with a short description and explanations of the PEM function, method and purpose

Hierarchical porous carbon foam electrodes fabricated from waste polyurethane elastomer template for electric double-layer capacitors

Plastic waste has become a major global environmental concern. The utilization of solid waste-derived porous carbon for energy storage has received widespread attention in recent times. Herein, we report the comparison of electrochemical performance of porous carbon foams (CFs) produced from waste polyurethane (PU) elastomer templates via two different activation pathways. Electric double-layer capacitors (EDLCs) fabricated from the carbon foam exhibited a gravimetric capacitance of 74.4 F/g at 0.1 A/g. High packing density due to the presence of carbon spheres in the hierarchical structure offered excellent volumetric capacitance of 134.7 F/cm3 at 0.1 A/g. Besides, the CF-based EDLCs exhibited Coulombic efficiency close to 100% and showed stable cyclic performance for 5000 charge–discharge cycles with good capacitance retention of 97.7% at 3 A/g. Low equivalent series resistance (1.05 Ω) and charge transfer resistance (0.23 Ω) due to the extensive presence of hydroxyl functional groups contributed to attaining high power (48.89 kW/kg). Based on the preferred properties such as high specific surface area, hierarchical pore structure, surface functionalities, low metallic impurities, high conductivity and desirable capacitive behaviour, the CF prepared from waste PU elastomers have shown potential to be adopted as electrodes in EDLCs

The effect of surface oxidation on the catalytic properties of Ga3Ni2 intermetallic compound for carbon dioxide reduction

Background: In a routine handling of a catalyst material, exposure to air can usually not be avoided. For noble metal catalysts that are resistant to oxidation, this is not an issue, but becomes important for intermetallic catalysts composed of two or more non-noble chemical elements that possess much different standard enthalpies of the oxide formation. The element with higher affinity to oxygen concentrates on the surface in the oxide form, whereas the element with lower affinity sinks into the subsurface region. This changes the number of active sites and the catalytic performance of the catalyst. We have investigated the instability of the surface composition to oxidation of the Ga3Ni2 noble metal-free intermetallic compound, a new catalyst for the CO2 reduction to CO, CH4 and methanol. Methods: The instability of the oxidized Ga3Ni2 surface composition to different heating-annealing conditions was studied by X-ray photoelectron spectroscopy (XPS), used to determine the elemental composition and the chemical bonding in the near-surface region. The dispersion of active sites available for the chemisorption of H-2 and CO on the Ga3Ni2 catalyst surface was determined by H-2 and CO temperature-programmed desorption. CO2 conversion experiments were performed by using the catalyst material reduced in hydrogen at temperatures of 300 and 600 degrees C. Results: XPS study of the Ga3Ni2 surface subjected to different heating-annealing conditions has revealed that the concentration of Ga at the oxidized surface is strongly enhanced and the concentration of Ni is strongly depleted with respect to the values in the bulk. By annealing the surface at 600 degrees C in ultra-high vacuum, the oxides have evaporated and thermal diffusion of atoms near the surface has partially reconstructed the surface composition towards the energetically more favorable bulk value, whereas annealing at a lower temperature of 300 degrees C was ineffective to change the surface composition. Catalytic tests were in agreement with the XPS results, where an increased CO2 conversion for the catalyst reduced with hydrogen at a higher temperature followed an increased Ni/Ga surface concentration ratio. Conclusions: The instability of the active surface chemical composition to oxidation in air must be taken into account when considering noble metal-free intermetallic catalysts as alternatives to the conventional catalysts based on noble metals. Ga3Ni2 and other Ga-Ni intermetallic compounds are good examples of binary intermetallic catalysts, whose catalytic performance is strongly affected by exposure to the air

Influence of geometry on pressure and velocity distribution in packed-bed methanol steam reforming reactor

The main tasks of this research is to propose several changes in the packed bed micro methanol steam reformer geometry in order to ensure its performance. The reformer is an integral part of the existing indirect internal reforming high temperature PEMFC and most of its geometry is already defined. The space for remodeling is very limited

Experimental Dimensional Accuracy Analysis of Reformer Prototype Model Produced by FDM and SLA 3D Printing Technology

The subject of this paper is the evaluation of the dimensional accuracy of FDM and SLA 3D printing technologies in comparison with developed reformer polymer electrolyte membrane (PEM) fuel cell CAD model. 3D printing technologies allow a bottom-up approach to manufacturing, by depositing material in layers to final shape. Dimensional inaccuracy is still a problem in 3D printing technologies due to material shrinking and residual stress. Materials used in this research are PLA (Polylactic Acid) for FDM technology and the standard white resin material for SLA technology. Both materials are commonly used for 3D printing. PLA material is printed in three different height resolutions: 0.3 mm, 0.2 mm and 0.1 mm. White resin is printed in 0.1 mm height resolution. The aim of this paper is to show how layer height affects the dimensional accuracy of FDM models and to compare the dimensional accuracy of FDM and SLA printed reformer models with the same height resolution

Design of polymeric electrolyte membrane reformer

This paper describes the design and manufacturing aspects of polymeric electrolyte membrane (PEM) reformer from the beginning step of realization that includes modelling of main parts of the reformer, adoptiog changes in shape aod dimensions, and manufucturing aod development of the reformer. For these purposes, one model in SolidWorks software was developed, and based on that model manufacturing was performed. Adopted changes in the refurmer are presented, along with detailed explaoations. Beside the main subject of this paper, general data about proton exchange membrane fuel cell are shown in the introdoction of this paper with short description aod explanations of PEM function, method and purpose

Renewable glycerol esterification over sulfonic-modified mesoporous silicas

SO3H-functionalised mesoporous materials with different pore structures (SBA-15 and SBA-16) were prepared by the post-synthesis surface modification. The materials were thoroughly characterized by X-ray powder diffraction, nitrogen physisorption, temperature-gravimetric analysis, elemental analysis and solid state NMR spectroscopy. The acidic properties were investigated by the temperature-programed desorption of ammonia. The catalytic performance of SO3H-functionalised mesoporous materials was studied in glycerol esterification with acetic acid.The different amount of silanol groups in the initial SBA-15 and SBA-16 silicas predetermined the different amount of propylsulfonic groups which are formed in them and therefore significantly influenced the acidity and the catalytic performance in glycerol esterification. Much higher amount of Brönsted acid sites was generated in SO3H modified SBA-15 catalyst, which exhibited higher activity to value-added triacetyl glycerol