Waste aluminum application as energy valorization for hydrogen fuel cells for mobile low power machines applications

This article proposes a new model of power supply for mobile low power machines applications, between 10 W and 30 W, such as radio-controlled (RC) electric cars. This power supply is based on general hydrogen from residual aluminum and water with NaOH, so it is proposed energy valorization of aluminum waste. In the present research, a theoretical model allows us to predict the requested aluminum surface and the required flow of hydrogen has been developed, also considering, in addition to the geometry and purity of the material, two key variables as the temperature and the molarity of the alkaline solution used in the hydrogen production process. Focusing on hydrogen production, isopropyl alcohol plays a key role in the reactor’s fuel cell vehicle as it filters out NaOH particles and maintains a constant flow of hydrogen for the operation of the machine, keeping the reactor temperature controlled. Finally, a comparison of the theoretical and experimental data has been used to validate the developed model using aluminum sheets from ring cans to generate hydrogen, which will be used as a source of hydrogen in a power fuel cell of an RC car. Finally, the manuscript shows the parts of the vehicle’s powertrain, its behavior, and mode of operationPostprint (published version

Anàlisi comparativa de propietats termo estructurals i elèctriques entre el polietilè d'alta densitat (HD-PE) i l’HD-PE reforçat amb pneumàtics al final de la seva vida útil. Estudi d'aplicació com a dielèctric

El propósito del presente trabajo pasa por analizar la permitividad y el factor de pérdidas tanto del polietile-no de alta densidad (HD-PE), como del compuesto de matriz polimérica (HD-PE)reforzado con neumáticos fuera de uso (Ground Tire Rubber: GTR), con el fin de demostrar su viabilidad como material aislante eléc-trico (dieléctrico). Como es sabido, la incorporación de negro de humo en un polímero permite modificar su conductividad, y cómo el GTR lleva un porcentaje significativo de negro de humo, algunas de las pro-piedades eléctricas del nuevo compuesto cambiaran significativamente con respecto al polímero que es altamente aislante. El estudio se centrará, en un rango de frecuencias y temperaturas aptas para demostrar la viabilidad de este nuevo compuesto en usos indus-triales, enfocándolo principalmente en el análisis de la Permitividad, ya que es una propiedad clave para los condensadores. No obstante, también se caracterizará el comportamiento térmico y estructural, haciendo especial énfasis en el rango de trabajo del condensador (por debajo de los 100ºC). Finalmente, con el análisis estructural, se pretende contribuir al conocimiento de estos materiales compuestos provenientes de reciclaje, y así, aprovechar su potencial de reutilización, haciéndolos atractivos para las empresas interesadas en su relación rendimiento/precio.The purpose of this work is to analyze the permittivity and the loss factor of both high-density polyethylene (HD-PE), as well as the polymer matrix composite (HD-PE) reinforced with end-of-life tires (Ground Tire Rubber: GTR), in order to demonstrate its viability as electrical insulating material (dielectric). As is known, the incorporation of carbon black in a polymer allows its conductivity to be modified, and since the GTR carries a significant percentage of carbon black, some of the electrical properties of the new compound will change significantly with respect to the polymer that is highly insulating. The study will focus on a range of frequencies and temperatures suitable to demonstrate the viability of this new composite in industrial uses, focusing mainly on the analysis of Permitivity, since it is a key property for capacitors. However, the thermal and structural behavior will also be characterized, with special emphasis on the capacitor working range (below 100ºC). Finally, with the structural analysis, it is inten-ded to contribute to the knowledge of these composite materials from recycling, and thus, take advantage of their potential for reuse, making them attractive for companies interested in their performance/price ratio.El propòsit del present treball passa per analitzar la permitivitat i el factor de pèrdues tant del polietilè d'alta densitat (HD-PE), com del compost de matriu polimèrica (HD-PE) reforçat amb pneumàtics fora d'ús (Ground Tire Rubber: GTR ), amb la finalitat de demostrar la seva viabilitat com a material aïllant elèctric (dielèctric). Com és sabut, la incorporació de negre de fum en un polímer permet modificar la seva conductivitat, i com el GTR porta un percentatge sig-nificatiu de negre de fum, algunes de les propietats elèctriques del nou compost canvien significativament respecte del polímer, que és altament aïllant. L'estudi es centrarà, en un rang de freqüències i temperatures aptes per demostrar la viabilitat d'aquest nou compost en usos industrials, enfocant principalment en l'anàlisi de la Permitivitat, ja que és una propietat clau per als condensadors. No obstant això, també es caracteritzarà el comportament tèrmic i estructural, fent especial èmfasi en el rang de treball d’un condensador (per sota dels 100 º C). Finalment, amb l'anàlisi estructural, es pretén contribuir a el coneixement d'aquests materials compostos provinents de reciclatge, i així, aprofitar el seu potencial de reutilització, fent-los atractius per a les empreses interessades en la seva relació rendiment/preu.Peer ReviewedPostprint (published version

Waste Aluminum Application as Energy Valorization for Hydrogen Fuel Cells for Mobile Low Power Machines Applications

This article proposes a new model of power supply for mobile low power machines applications, between 10 W and 30 W, such as radio-controlled (RC) electric cars. This power supply is based on general hydrogen from residual aluminum and water with NaOH, so it is proposed energy valorization of aluminum waste. In the present research, a theoretical model allows us to predict the requested aluminum surface and the required flow of hydrogen has been developed, also considering, in addition to the geometry and purity of the material, two key variables as the temperature and the molarity of the alkaline solution used in the hydrogen production process. Focusing on hydrogen production, isopropyl alcohol plays a key role in the reactor’s fuel cell vehicle as it filters out NaOH particles and maintains a constant flow of hydrogen for the operation of the machine, keeping the reactor temperature controlled. Finally, a comparison of the theoretical and experimental data has been used to validate the developed model using aluminum sheets from ring cans to generate hydrogen, which will be used as a source of hydrogen in a power fuel cell of an RC car. Finally, the manuscript shows the parts of the vehicle’s powertrain, its behavior, and mode of operation

Comparison of Mechanical and Electrical Characteristics of Various Polymers Blended with Ground Tire Rubber (GTR) and Applications

The massive manufacture of tires and the difficulty of reducing the stocks of used tires is a serious environmental problem. There are several methods used for recycling wasted tires, one of which is mechanical crushing, in which vulcanized rubber is separated from steel and fibers, resulting in a ground tire rubber (GTR). This can be used in applications such as insulation for footwear work. The aim of the present investigation is to evaluate the use of the GTR when it is mixed with several types of polymer matrix by means of measuring its dielectric and mechanical properties of the resulting composites (polymer + GTR). The analysis is carried out using seven polymeric matrices mixed with different GTR concentrations. With the present study, it is intended to propose a way to reuse the tires out of use as an industrial work footwear insulation, by demonstrating the feasibility of the properties analyzed

Application properties analysis as a dielectric capacitor of end-of-life tire-reinforced HDPE

The purpose of the present research is to obtain waste of polymeric composite as an insulator capacitive application. Rubber materials, once they end their useful life, may be difficult to reuse or recycle. At present, research only uses one tire recycling method, which involves grinding and separating steel and fibers from vulcanized rubber, and then using the rubber particles for industrial capacitors. The methodology for this research is to compare the permittivity (e' and e¿) between high-density polyethylene (HDPE) and the polymer matrix compound, consisting of an HDPE polymeric matrix blended with end-of-life tire particles (ground tire rubber (GTR)), to analyze the feasibility of using such tires as electrically insulating materials (dielectrics). The incorporation of carbon black in the GTR compounds modifies conductivity; GTRs carry a significant amount of carbon black, and therefore some electrical properties may change significantly compared to highly insulating polymer substrates. The performed experimental study is based on a dynamic electric analysis (DEA) test developed in the frequency range of 10-2 Hz to 3 MHz and at different temperatures (from 35 to 70 °C) of different samples type: HDPE neat and HDPE compounds with 10%, 20% and 40% of GTR loads. A sample’s electrical behavior is checked for its dependence on frequency and temperature, focused on the permittivity property; this is a key property for capacitive insulators and is key for examining the possible applications in this field, for HDPE + GTR blends. Results for the permittivity behavior and the loss factor show different electrical behavior. For a neat HDPE sample, no dependence with frequency nor temperature is shown. However, with the addition of 10%, 20%, and 40% amount of GTR the HDPE compounds show different behaviors: for low frequencies, interfacial polarization relaxation is seen, due to the Maxwell–Wagner–Sillars (MWS) effect, performed in heterogeneous materials. In order to analyze thermal and morphological properties the differential scanning calorimetry (DSC) test and scanning electron microscopy (SEM) have been used. Results obtained show that adding waste tire particles in an HDPE matrix allows HDPE + 40% GTR blends to act as a dielectric in capacitors, increasing the capacitor dielectric efficiency in the low frequencies due to the MWS effect, which increases the dielectric constant.Peer ReviewedPostprint (published version

Influence of tire rubber particles addition in different branching degrees polyethylene matrix composites on physical and structural behavior

Waste from pneumatic wheels is one of the major environmental problems, and the scientific community is looking for methods to recycle this type of waste. In this paper, ground tire rubber particles (GTR) from disused tires have been mixed with samples of low-density polyethylene (LDPE) and high-density polyethylene (HDPE), and morphological tests have been performed using scanning electron microscopy (SEM), as well as the dynamic electric analysis (DEA) dielectric characterization technique using impedance spectroscopy. From this experience, how GTR reinforcement influences polyethylene and what influence GTR particles have on the branched polyethylene has been detected. For pure LDPE samples, a Debye-type dielectric behavior is observed with an imperfect semicircle, which depends on the temperature, as it shows differences for the samples at 30 ¿C and 120 ¿C, unlike the HDPE samples, which do not show such a trend. The behavior in samples with Debye behavior is like an almost perfect dipole and is due to the crystalline behavior of polyethylene at high temperature and without any reinforcement. These have been obtained evidence that for branched PE (LPDE) the Maxwell Wagner Sillars (MWS) effect is highly remarkable and that this happens due to the intrachain polarization effect combined with MWS. This means that the permittivity and conductivity at LDPE/50%GTR are high than LDPE/70%GTR. However, it does not always occur that way with HDPE composites in which HDPE/70%GTR has the highest values of permittivity and conductivity, due to the presence of conductive fraction (Carbon Black-30%) in the GTR particles and their dielectric behaviorPostprint (published version