High Temperature Fuel Cells Research Articles

Thermal integration process for waste heat recovery of SOFC to produce cooling/H2/power/freshwater; cost/thermal/environmental optimization scenarios

High-temperature fuel cells (HT-FCs) indeed hold significant promise for enhancing energy systems' efficiency and environmental sustainability. Consequently, there is growing interest in exploring and developing innovative strategies to optimize the integration of heat recovery processes with HT-FC technology. The current research presents an innovative and environmentally friendly poly-generation unit that integrates advanced subprocesses to generate essential products. These final products include electricity, refrigeration, pure water, and hydrogen. This study signifies a significant step towards sustainable and efficient energy production while meeting diverse needs for different utilities. The design unit incorporates a novel modified dual ejector-based organic flash cycle, reverse osmosis water purification, and a water electrolyzer for hydrogen extraction, all integrated with a high-temperature solid oxide fuel cell. Energy, exergy, economic, and environmental (4E) analysis is conducted to thoroughly evaluate the proposed plan. Furthermore, a comprehensive parametric analysis and sensitivity study are performed to pinpoint the key design parameters of the poly-generation unit. To attain the optimal operational status of the poly-generation unit, a three-objective NSGA-II optimization technique is employed to fine-tune the system's performance within the exergy-cost-environmental framework. This approach aims to strike a balance between maximizing efficiency, minimizing costs, and reducing environmental impact for sustainable operations. In addition, a net present value analysis spanning a 20-year timeframe was conducted to assess the profitability of the devised unit. Based on the findings, it is evident that the sensitivity index of the fuel cell operating temperature carries substantial importance, registering a notable value of 0.60. Additionally, the optimization outcomes reveal the system's enhanced performance metrics: an exergetic efficiency of 41.11 %, a unit cost of 58.96 $/GJ, and a carbon dioxide emission reduction rate of 418 kg/MWh. Also, the unit's payback period is shortened from 11.33 years to 8.817 years. Moreover, it improved the unit's sustainability index and net present value, raising them from 1.544 to 4.98 M$ to 1.66 and 7.38 M$.

Perovskite Type Lanthanum Oxide and Graphene Oxide (LaFeO3-GO) Composite as (Low Overpotential) ORR Catalyst for Low and High Temperature Fuel Cells

Due to depletion of fossil fuel and their environmental effect, renewable resources are the prime interest in which fuel cell technology competes with fossil fuels but their ORR at cathode restrict its efficiency. Perovskite type orthorhombic structure of LaFeO3 incorporated GO has ability to use as catalyst in low and high temperature fuel cells having non-agglomerated particles in nanometers range (20- 100), high temperature stability, low overpotential of about 0.6V, ECSA of about 13.22 m2g-1 and current density of about 0.012 mAcm-1. Results open further research directions in supercapacitors, batteries, biological fuel cells, and applications which requires high temperature stability.

Computational and Experimental Research on the Influence of Supplied Gas Fuel Mixture on High-Temperature Fuel Cell Performance Characteristics

Currently, the process of creating industrial installations is associated with digital technologies and must involve the stage of developing digital models. It is also necessary to combine installations with different properties, functions, and operational principles into a single system. Some tasks require the use of predictive modeling and the creation of “digital twins”. The main processes during the fuel cell modeling involve electrochemical transformations as well as the movement of heat and mass flows, including monitoring and control processes. Numerical methods are utilized in addressing various challenges related to fuel cells, such as electrochemical modeling, collector design, performance evaluation, electrode microstructure impact, thermal stress analysis, and the innovation of structural components and materials. A digital model of the membrane-electrode unit for a solid oxide fuel cell (SOFC) is presented in the article, incorporating factors like fluid dynamics, mass transfer, and electrochemical and thermal effects within the cell structure. The mathematical model encompasses equations for momentum, mass, mode, heat and charge transfer, and electrochemical and reforming reactions. Experimental data validates the model, with a computational mesh of 55 million cells ensuring numerical stability and simulation capability. Detailed insights on chemical flow distribution, temperature, current density, and more are unveiled. Through a numerical model, the influence of various fuel types on SOFC efficiency was explored, highlighting the promising performance of petrochemical production waste as a high-efficiency, low-reagent consumption fuel with a superior fuel utilization factor. The recommended voltage range is 0.6–0.7 V, with operating temperatures of 900–1300 K to reduce temperature stresses on the cell when using synthesis gas from petrochemical waste. The molar ratio of supplied air to fuel is 6.74 when operating on synthesis gas. With these parameters, the utilization rate of methane is 0.36, carbon monoxide CO is 0.4, and hydrogen is 0.43, respectively. The molar ratio of water to synthesis gas is 2.0. These results provide an opportunity to achieve electrical efficiency of the fuel cell of 49.8% and a thermal power of 54.6 W when using synthesis gas as fuel. It was demonstrated that a high-temperature fuel cell can provide consumers with heat and electricity using fuel from waste from petrochemical production.

Achieving 1060mWcm-2 with 0.6mgcm-2 Pt Loading Based on Imidazole-Riched Semi-Interpenetrating Proton Exchange Membrane at High-Temperature Fuel Cells.

Enhancing phosphoric acid (PA) doping in polybenzimidazole (PBI) membranes is crucial for improving the performance of high-temperature proton exchange membrane fuel cells (HT-PEMFCs). However, excessive PA uptake often leads to drawbacks such as PA loss and compromised mechanical properties when surpassing PA capacity of PBI basic functionality. Herein, a new strategy that integrates high PA uptake, mechanical strength, and acid retention is proposed by embedding linear PBI chains into a crosslinked poly(N-vinylimidazole) (PVIm) backbone via in-situ polymerization. The imidazole (Im)-riched semi-interpenetrating polymer network (sIPN) membrane with high-density nitrogen moieties, significantly enhancing the PA doping degree to 380% shows an excellent conductivity (0.108Scm-1). Meanwhile, the crosslinking structure in the sIPN membrane ensures adequate mechanical properties, low hydrogen permeability, and a relatively low swelling ratio. As a result, the single cell based on the membrane achieves the highest power density of 1060mWcm-2 with a low Pt loading (0.6mgcm-2) up to now and exhibits excellent fuel cell stability.

Hydrogen Sulphide and Carbonyl Sulphide Removal from Biogas for Exploitation in High-Temperature Fuel Cells

Fuel cells powered by biogas for decentralised cogeneration of heat and power are an attractive alternative to combustion technologies. However, biogas contains sulfur-based compounds (H2S, COS, DMS, siloxanes), which are harmful to fuel cells. This work was carried out in the framework of the European project Waste2Watts, involving the laboratories of Politecnico di Torino, ENEA, and PSI. The aim is to design and test a flexible and cost-effective cleaning unit to remove impurities for the use of biogas in high-efficiency fuel cell systems. The focus is on small- to medium-sized farms for which deep cleaning of biogas by adsorption materials is a suitable techno-economic solution to avoid intensive gas processing treatments. The ability of commercial adsorption materials (activated carbons, metal oxides, and metal hydroxides) to remove hydrogen sulphide and carbonyl sulphide was tested under different biogas compositions (oxygen and humidity). After evaluating the results, three plant configurations were proposed to optimally utilise the potential of the sorbents. Indeed, the RGM3 sorbent has proven to be an effective solution for removing H2S and COS under humid conditions (50% RH), whilst R7H and R8C sorbents are better suited for removing H2S and COS, respectively, in dry biogas conditions.Graphical abstract

Thermodynamic Performance Comparisons of Ideal Brayton Cycles Integrated with High Temperature Fuel Cells as Power Sources on Aircraft

Developing hybrid electric aircraft is propitious to reducing carbon dioxide emissions and fuel consumption. Combustion engines coupled with solid oxide fuel cells are proposed for aircraft propulsion systems, where the compressor is powered by fuel cells instead of turbines. The thermal cycle of the new engine is obviously different from that of conventional combustion engines and can be characterized in the temperature entropy diagram under some reasonable assumptions, which were analyzed and investigated. Performance parameters, such as the specific thrust, are derived and can be expressed by several fundamental thermal parameters. Three different cycles integrating Brayton cycles and SOFC are shown. The main conclusions are as follows: (1) The maximum operating pressure ratio of the Brayton cycles integrated with fuel cells is 32. The maximum thermal efficiency of the cycle at the lowest combustion temperature is 82.2%, while that of the BC is 65.1% at the high combustion temperature. (2) The new cycles can not work if the combustion temperature is lower than 1350 K. Otherwise, the fuel utilization will be too huge.

A Novel High Temperature Fuel Cell Proton Exchange Membrane with Nanoscale Phase Separation Structure Based on Crosslinked Polybenzimidazole with Poly(vinylbenzyl chloride)

A semi-aromatic polybenzimidazole (DPBI) is synthesized via polycondensation of decanedioic acid (DCDA) and 3,3-diaminobenzidine (DAB) in a mixed phosphorus pentoxide/methanesulfonic acid (PPMA) solvent. Ascribing to in-situ macromolecular crosslinker of ploly((vinylbenzyl chloride) (PVBC), a robust crosslinked DPBI membrane (DPBI-xPVBC, x refers to the weight percentage of PVBC in the membrane) can be obtained. Comprehensive properties of the DPBI and DPBI-xPVBC membranes are investigated, including chemical structure, antioxidant stability, mechanical strength, PA uptake and electrochemical performances. Compared with pristine DPBI membrane, the PA doped DPBI-xPVBC membranes exhibit excellent antioxidative stability, high proton conductivity and enhanced mechanical strength. The PA doped DPBI-10PVBC membrane shows a proton conductivity of 49 mS cm-1 at 160 °C without humidification. Particularly, it reveals an enhanced H2/O2 single cell performance with the maximum peak power density of 405 mW cm-2, which is 29% higher than that of pristine DPBI membrane (314 mW cm-2). In addition, the cell is very stable in 50 h, indicating the in-situ crosslinked DPBI with a macromolecular crosslinker of PVBC is an efficient way to improve the overall performance of HT-PEMs for high performance HT-PEMFCs.

Integrating a High Temperature Fuel Cell with СО<sub>2</sub> Capture System into Thermal Power Plant Energy Cycle

The molten carbonate fuel cell allows for capturing, separating and concentrating CO2 as it passes through the carbonate melt from the cathode side to the anode side, while simultaneously generating electricity and heat. The article presents the technology and flow diagram of a system for capturing CO2 from flue gases of a thermal power plant in a high-temperature fuel cell on molten carbonates with subsequent conversion and utilization of gaseous combustible products in the energy cycle of a thermal power plant. The fuel cell runs on natural gas with internal reforming. After the fuel cell, the gas leaving the anode is sent to the conversion unit where, in reaction with carbon at high temperatures, combustible gases are formed that are suitable for re-combustion in the turbine. For power plants and a system for capturing and converting carbon dioxide, thermodynamic, technical and economic calculations were carried out. The efficiency of a high-temperature fuel cell is 42 %. In the baseline scenario, the net energy efficiency of the plant is 61 % while a CO2 capture ration is 80–85 %. The return of fuel gases after the conversion of carbon dioxide, taking into account their calorific value, makes it possible to additionally increase the electric power of the thermal power plant up to 20 %. With a unit cost of a fuel cell of 1300 EUR/kW and a price of natural gas of 0.04 EUR/kW, the total electricity cost of the plant is 0.074 EUR/kW. The results show that the proposed system is attractive for natural gas power generation with CO2 capture.

Constructing High-Density Hydrogen Bonding Networks via Introducing the Bipyridine Group for High-Performance Fuel Cell Proton Exchange Membranes

Constructing high-density hydrogen bonding networks is crucial to improve the proton conductivity of proton exchange membranes (PEMs) and the single-cell output power of high-temperature fuel cells (HTFCs). In this work, a series of benzimidazole polymers containing a pyridine group in the backbone are successfully synthesized via copolymerization. The high-density hydrogen network is constructed via blending the polyether polybenzimidazole (OPBI) with the bipyridine polybenzimidazole copolymer, and the 1,3,5-triglycidyl isocyanurate that contains nitrogen atoms and hydroxyl groups is used as a cross-linking agent. As a result, the proton conductivity and the output power density of the single cell are significantly enhanced by the high-density hydrogen bonding network. The single-cell performance of 693 mW cm–2 is achieved in the cross-linked OPBI/copolymer blend membranes containing pyridine group under a saturated phosphoric acid (PA) adsorption (284%). Even under the low PA uptake (178%), the proton conductivity (0.050 S cm–1) is 2.1 times that of the OPBI membrane (0.024 S cm–1), and the output power density of the single-cell performance (501 mW cm–2) is 1.4 times that of the OPBI membrane (358 mW cm–2). The results demonstrate that introducing nitrogen sites into polybenzimidazole cross-linked membranes is an effective strategy for preparing high-performance fuel cell PEMs.

Interval Extension of Neural Network Models for the Electrochemical Behavior of High-Temperature Fuel Cells

In various research projects, it has been demonstrated that feedforward neural network models (possibly extended toward dynamic representations) are efficient means for identifying numerous dependencies of the electrochemical behavior of high-temperature fuel cells. These dependencies include external inputs such as gas mass flows, gas inlet temperatures, and the electric current as well as internal fuel cell states such as the temperature. Typically, the research on using neural networks in this context is focused only on point-valued training data. As a result, the neural network provides solely point-valued estimates for such quantities as the stack voltage and instantaneous fuel cell power. Although advantageous, for example, for robust control synthesis, quantifying the reliability of neural network models in terms of interval bounds for the network’s output has not yet received wide attention. In practice, however, such information is essential for optimizing the utilization of the supplied fuel. An additional goal is to make sure that the maximum power point is not exceeded since that would lead to accelerated stack degradation. To solve the data-driven modeling task with the focus on reliability assessment, a novel offline and online parameterization strategy for interval extensions of neural network models is presented in this paper. Its functionality is demonstrated using real-life measured data for a solid oxide fuel cell stack that is operated with temporally varying electric currents and fuel gas mass flows.

Operational and economic performance analysis of a high-temperature fuel cell cogeneration plant

To increase reliability, resiliency, and overall efficiency, distributed generators are being deployed at sites including hotels, hospitals, and data centers. This study provides a novel evaluation of the operational and economic performance of a megawatt-class high-temperature fuel cell (HTFC) cogeneration plant coupled to a 200RT absorption chiller. With unique access to high-resolution data, comprehensive analyses are conducted to assess both the plant operational and, combined with electric utility data, economic performance including identifying the operational parameters that most affect economic performance. The analyses reveal the challenges in achieving viable operational and economic performance of distributed generators, the difficulty of acquiring detailed operational data, and the complex and varying array of electric utility rates and demand charges. The fluctuation in electric and natural gas utility rates represent the largest impact on the economic performance. While the fuel cell can reduce the monthly demand charge that would otherwise be applied, a trip of the fuel cell can result in a monthly demand charge and compromise the financial viability of the plant. In the present case, the first four years of operation resulted in a net loss rather than the savings expected. Strategies to yield a net gain are presented.

High-temperature PEM Fuel Cell Characterization: an Experimental Study Focused on Potential Degradation due to the Polarization Curve

High-Temperature Proton Exchange Membrane Fuel Cell constant current ageing tests highlighted that the characterizations used to monitor the state of health of single cells could be potentially degrading. An experimental campaign to analyze potential degradation due to polarization curves was carried out. More exactly, four methodologies to generate a polarization curve including Electrochemical Impedance Spectroscopies (EIS) were cycled 30 times. The tested single cells were based on a commercial PBI Membrane Electrodes Assembly (MEA) with an active surface of 45 cm2 (BASF Celtec®-P 1100 type). Before the first cycling test and after the last cycling one, complete characterizations, composed by a voltammetry and a polarization curve including EIS, were performed. The results show that one of the MEA has a voltage which increased for one of the four methods to obtain the polarization curve. This growth is linked to a decrease of ohmic losses: in an unexpected way, it could be considered as a way to improve the break-in period. Similarly, the monitoring of CO2 emission (as corrosion has been suspected to be involved at high voltage, i.e. low current density) confirms the potential degradation of the electrodes during the measurement of the polarization curve.

Improvement of Performance and Lifetime of Polybenzimidazole Membranes in High Temperature Fuel Cells by Incorporation of Muscovite

Polybenzimidazole (PBI) is a basic aromatic heterocyclic polymer with excellent thermal and chemical stability. The phosphoric acid (PA) doped PBI and its derivative membranes have high proton conductivity, low gas permeability, good fuel impurity tolerance, and excellent oxidative and thermal stability at temperatures up to 200 °C [1], hence, PA doped PBI is a promising candidate for high-temperature proton exchange membrane fuel cells. However, PA doped PBI membranes also has some limitations, including the dehydration of phosphoric acid above 140 °C, PA leaching out of the membranes, and deterioration of membrane mechanical strength especially at high acid doping level.The incorporation of clay minerals into membranes attract a great interest due to their hygroscopicity, high surface area and cheap cost [2]. The hygroscopic properties of clay minerals can increase the humidity inside the membranes, interact with PA molecules and maintain a strong proton conductivity. Here we present work on the incorporation of a cheap muscovite into the PBI membrane. As the muscovite is highly hygroscopic and has hydroxyl groups on the surface, an optimal cell performance was observed when the loading of muscovite is 1 wt.%. The PBI membrane with 1 wt.% muscovite showed the membrane resistance of 189 mohm cm2 and peak power density of 612 mW cm-2 at 150 °C, 26% higher than the pure PBI membrane with the membrane resistance of 235 mohm cm2 and the power density of 485 mW cm-2. Furthermore, the durability of inorganic-organic composite membranes was tested by an accelerated stress test (AST) operating the membrane electrode assembly between 0.6 A cm−2 and 1.0 A cm−2 [3]. After running around 50 h AST, the composite PBI membrane with 1 wt.% muscovite showed much lower degradation (9.3% at 0.6 A cm−2 and 12.8% at 1.0 A cm−2) than the pure PBI membrane (11.2% at 0.6 A cm−2 and 22.6% at 1.0 A cm−2). The improved durability of the composite membranes might be explained by the muscovite forming hydrogen bonding with PA molecules and polymer chains, which alleviates the degradation of polymer chains and PA leaching out of the membranes. The PA distribution and retention properties of the composite membranes were also characterized by energy dispersive X-ray spectroscopy and electron probe micro-analysis.

Importance of Solid-Liquid Interface on Electrochemical Performance of Doped Ceria-Carbonate Composite Electrolyte for High Temperature Fuel Cells

Samaria-doped ceria (SDC)/carbonate composite electrolytes were recently developed for high temperature fuel cell applications. Conventional LiAlO2 was replaced by SDC as the matrix phase and lithium/sodium carbonate was selected as the second phase. In this study, the porous SDC (Sm0.2Ce0.8O1.9; SDC) matrix was fabricated. Then, the molten lithium sodium carbonate ((Li0.52Na0.48)2CO3; LNC) is infiltrated to form a composite electrolyte.From the cell testing in this study, the SDC/LNC cell show higher power density (340mW/cm2) than LiAlO2/LNC cell (154mW/cm2) at 650°C. This result suggests that the SDC-LNC composite electrolyte may be a better electrolyte for high temperature applications. In addition, the effects of solid-liquid interface was investigated using matrix with various pore sizes ranging from 5 to 20 μm. When the pore size of structural matrix was changed from 20 to 5 μm, the power density measured increased from 126 to 340mW/cm2 at 650oC. This can be attributed to the small pores having higher interface area, and the increased interface area is effective for transportation of ions. In other words, the super-ionic conducting path may exist at this interface, where the defect concentrations are high.Through the results and calculations of the designed experiments, the importance of the interface is realized. Finally, it may be concluded that the interface was mainly contributed by oxygen ion conduction using DC measurement under the control of different atmospheres and TEM analysis. High-resolution SEM, XRD, and Electrochemical Impedance Spectroscopy were employed to conduct microstructural, structural and impedance analyses.

Graphene-Based Materials for High Temperature Fuel Cell Applications

High-Temperature Hydrogen Proton Exchange Membrane (HT-PEMFC) operates at temperatures up to 200 oC using Phosphoric Acid (PA) doped Poly[2,2′-m-(phenylene)-5,5′-benzimidazole] (PBI) membrane. PBI does not have a good proton conductivity by itself it should doped with PA to establish a complete network of hydrogen bond (Grotthuss mechanism). HT-PEMFC and PBI performance depends on the doping level of PA and consequently of Physico-chemical properties of this acid [1,2].One of the main advantages of these fuel cells is that PA has a low vapour pressure at these temperatures allowing long-term operation of these fuel cells without any electrolyte loss, which is one of the principal aspect defined by US Department of Energy as 2015 targets [1,2]. Additionally, the PA is an excellent proton conductor material being comparable to typical Nafion membranes and without the necessity of additional gas humidification due to the fast Grotthus mechanism. However, PBI/PA membranes exhibit PA migration form cathode to anode at the high current density and high temperatures. This loss of PA and its redistribution within the Membrane Electrode Assembly (MEA) have a range of potential implications for fuel cell degradation such as decreasing of PA doping level resulting in increased membrane resistance, lower proton conductivity and as a consequence, decreasing performance and lifetime [1,2].To stop the PA leaching from the cathode side and consequently to reduce the negative effects produced on the fuel cell, we propose to use a barrier to avoid PA leaching. Single Layer Graphene (SLG) has a 2D hexagonal structure, which acts a since material to block all atoms and molecules from passing through except protons, as has been proved by Hu et al.[3] SLG has been already used on low temperature PEM fuel cells to reduce fuel crossover and improve the efficiency of the fuel cell [4]. However, despite the advantageous properties of SLG, it is still presenting some drawbacks, notably due to the complex process to proceed it and its high cost. These limitations leave an open window to Graphene based materials such a Graphene Oxide, which has attractive properties to as filler materials in PBI membranes due to its chemical functionalization and its non-porous structure leading to additional resistance for mass transport and increases the tortuosity of the permeation pathways allowing a higher selectivity [5].This work presents two different approaches to stop the PA leaching in HT-PEMFC by incorporating SLG and GO-composite membranes into the MEA. The addition of the SLG produced by Chemical Vapour Deposition (CVD) has demonstrated no change in the proton conductivity, supporting the hypothesis that SLG is a good proton conductor [3]. In addition to that, SLG has extraordinary barrier properties, leading a decrease of the PA leaching and enhancing the HT-PEMFC performance as well as the membrane degradation.Although positive results have been obtained by adding SLG into the fuel cells, GO-composite membrane have been also evaluated within the MEA. Exfoliated Graphene Oxide has been synthesized by electrochemical exfoliation of graphite and has been incorporated as a filler into the PBI, obtaining successful results in terms of performance and long term work.

Importance of Mixed-Conducting Materials for High-Temperature Fuel Cells Applications

In many electrochemical devices, mixed ionic/electronic conduction have received great attention. For instance, oxygen transport membrane (OTM) based on (Ba,Sr)(Co,Fe)O3 perovskite exhibit unique hole/oxygen ion mixed conduction behavior for oxygen separation application.Accordingly, electrodes/electrolytes exhibiting both electronic and/or multiple ionic conducting properties have been used for high temperature fuel cell application. For example, mixed conducting electrodes based on composite electrode (e.g. LSM/SDC, LSM/YSZ) show improved SOFC performance in comparison to conventional electrode. Such unique conduction behavior may be rationalized based on defect chemistry consideration. Thus, the materials processing and microstructure design may become key issues to optimize their mixed conduction properties. For instance, better hole and oxygen conducing perovskite may be obtained when desired aliovalent dopant and oxidizing atmosphere are used.Thus, the objective of this work is to conduct (1) fabrication/design of MIEC through defect-favored processing, (2) microstructure development for better gas transport, (3) characterization of conduction/interfacial kinetics for better electrodes/electrolytes performance. Desired analytical equipment such as SEM, XRD, electrochemical impedance spectroscopy (EIS) and cell testing are performed to conduct microstructural, structural and impedance analyses. The electrical conduction behavior of composite electrode/electrolytes will be discussed based on defect chemistry consideration and individual microstructure and morphology including pore size, pore distribution and interface area.

Nonlinear Model Predictive Control of an Autonomous Power System Based on Hydrocarbon Reforming and High Temperature Fuel Cell

The integration and control of energy systems for power generation consists of multiple heterogeneous subsystems, such as chemical, electrochemical, and thermal, and contains challenges that arise from the multi-way interactions due to complex dynamic responses among the involved subsystems. The main motivation of this work is to design the control system for an autonomous automated and sustainable system that meets a certain power demand profile. A systematic methodology for the integration and control of a hybrid system that converts liquefied petroleum gas (LPG) to hydrogen, which is subsequently used to generate electrical power in a high-temperature fuel cell that charges a Li-Ion battery unit, is presented. An advanced nonlinear model predictive control (NMPC) framework is implemented to achieve this goal. The operational objective is the satisfaction of power demand while maintaining operation within a safe region and ensuring thermal and chemical balance. The proposed NMPC framework based on experimentally validated models is evaluated through simulation for realistic operation scenarios that involve static and dynamic variations of the power load.

Application of Catalytic Technologies for Power Plants Based on High-Temperature Fuel Cells

Application of Catalytic Technologies for Power Plants Based on High-Temperature Fuel Cells

Application of Catalytic Technologies for Power Plants Based on High-Temperature Fuel Cells

Application of Catalytic Technologies for Power Plants Based on High-Temperature Fuel Cells

LPT (Local Public Transport) electric buses: innovative solutions to reduce the energy absorption of auxiliaries

The focus of the study is the analysis and sizing of the air conditioning system on board the vehicle which operates in thermal transient for the duration of the typical mission, using “fan coil” type air conditioning devices powered by a hot or cold heat vector fluid loaded into “electro-thermal” charging station and the related ground cogeneration plant (at the BUS terminus). For winter air conditioning, it was assumed that a heat transfer fluid at a temperature of 90 ° C could be stored on board. This value allows the use of water as a heat transfer fluid without pressurizing the systems, minimizing costs and supply problems, and is compatible with the characteristics of ICE cogeneration systems. For summer air conditioning, it was assumed that ice or fluid at a temperature of -20 ° C could be loaded. Also in this case it was decided to operate with a common fluid, such as a solution of water and salt (e.g. calcium chloride CaCl2). A comparative analysis of two solutions was carried out: the first involves the standard solution with BUS air conditioning system with heat pump powered by traction batteries charged by the grid and the second one analyzes the use of a high temperature Fuel Cell in a trigenerative configuration with refrigeration unit absorption fueled by the fumes of the FC. The trigeneration plant produces 100 kW of electricity via SOFC (Solid Oxide Fuel Cell) and, through an exchanger, water at 95 ° C which is stored on board the BUS for winter heating and feeds an absorption refrigeration machine that produces fluid at a temperature of -20 ° C for summer conditioning. For the two solutions, the savings of non-renewable primary energy and the reduction of GHG emissions compared to the standard solution (recharging the electric BUS from the network with on-board air conditioning powered by the traction batteries) are calculated through a WTW analysis. Consumption and emissions of electric powertrains, potentially for consumption and zero emissions, are closely linked to the methods of production and distribution of electricity.