Comparatative analysis on various reformers supplied with different fuels and integrated with high temperature PEM fuel cells

Ellamla, Harikishan R.; Bujło, Piotr; Sita, Cordellia; Pasupathi, Sivakumar

doi:10.1016/j.ces.2016.06.065

Cited by 13 publications

(2 citation statements)

References 20 publications

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“…Thus, they are close to ideal fuel cells for on-board and medium-scale stationary FC applications. While various hydrocarbon fuels can be reformed to provide hydrogen for PEMFCs, methanol is regarded as one of the most suitable fuels for the purpose − due to relatively low temperature reforming, miscibility in water, low freezing point, biodegradability and possibility to be obtained from renewable sources. Although methanol can be reformed by any of the partial oxidation, steam reforming and autothermal reforming processes, steam reforming is widely adopted for its high hydrogen yield.…”

Section: Introduction and Motivationmentioning

confidence: 99%

Minimizing Heat Transfer Resistance in an Integrated Methanol Steam Reformer Designed Using Space-Filling Curves

Khan

Jayanti

2022

Ind. Eng. Chem. Res.

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Conventional packed bed methanol steam reformers producing hydrogen for PEM fuel cells have an inherent trade-off problem between simultaneously attaining high methanol conversion and low carbon monoxide production, owing to high thermal resistance in the packed bed. A sophisticated reformer design using Hilbert’s space-filling curves is proposed and demonstrated using CFD modeling and simulation. The reactor comprises a flow-through domain divided into two interdigitating but nonmixing continua that are separated by a thin wall, providing high interfacial area for heat transfer and surface reactions. The interfacial wall is modeled as coated with catalyst for performing reforming on one side and fuel cell anode exhaust hydrogen combustion on the other side. About 84% methanol conversion and CO production less than 2% was achieved due to remarkable reduction in heat transfer resistance. External mass transfer controlled the reactor operation, while reaction kinetics exhibited nontrivial influence on reactor performance.

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Section: Introduction and Motivationmentioning

confidence: 99%

Minimizing Heat Transfer Resistance in an Integrated Methanol Steam Reformer Designed Using Space-Filling Curves

Khan

Jayanti

2022

Ind. Eng. Chem. Res.

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“…Numerical studies of RMFC systems often use Aspen Plus software for mass-and energy-balance calculations and another programmable software (e.g., Matlab, Ansys Fluent, Comsol Multiphysics, etc.) to simulate the operation of the HT PEMFC stack or the entire system [16][17][18][19]. There are studies that use Matlab/Simulink software for the creation of applicative system models that are corroborated by experimental data [20,21].…”

Section: Introductionmentioning

confidence: 99%

Conceptual design of an integrated thermally self-sustained methanol steam reformer – High-temperature PEM fuel cell stack manportable power generator

Lotrič

Sekavčnik

Pohar

et al. 2017

International Journal of Hydrogen Energy

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We have investigated the concept of an integrated system for small, manportable power units. The focus of this study is the direct thermal coupling of a methanol steam reformer (MSR) and a hightemperature proton exchange membrane fuel cell (HT PEMFC) stack. A recently developed lowtemperature (LT) MSR catalyst (CuZnGaOx) was synthesized and tested in a designed reforming reactor. The experimental data show that at 200 °C the complete conversion of methanol is achievable with a hydrogen yield of 45 cm 3 min -1 gCAT -1 . An experimental setup for measuring the characteristics of the integrated system was designed and used to measure the characteristics of the two-cell HT PEMFC stack. The obtained kinetic parameters and the HT PEMFC stack characteristics were used in the modeling of the integrated system. The simulations confirmed that the integrated LT MSR/HT PEMFC stack system, which also includes a vaporizer, can achieve a thermally selfsustained working point. The base-case scenario, established on experimental data, predicts a power output of 8.5 W, a methanol conversion of 98.5%, and a gross electrical efficiency (based on the HHV) of the system equal to 21.7%. However, by implementing certain measures, the power output and the electrical efficiency can readily be raised to 11.1 W and 35.5%, respectively.

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High Temperature Polymer Electrolyte Membrane Fuel Cells for Integrated Fuel Cell – Methanol Reformer Power Systems: A Critical Review

Zhang

Xiang

et al. 2018

Advanced Sustainable Systems

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be generally divided into low temperature fuel cells such as alkaline fuel cells (AFCs), polymer electrolyte membrane fuel cells (PEMFCs) and phosphoric acid fuel cells (PAFCs) and high temperature fuel cells such as molten carbonate fuel cells (MCFCs) and solid oxide fuel cells (SOFCs). Due to their high power-output, fast start-up/shut-down cycles and continuous power supply mode, PEMFCs are particularly applicable as energy sources in portable electronic devices, communication and transportation applications. [1] The core component of PEMFCs is the membrane-electrode-assembly (MEA), which consists of a proton conducting polymer electrolyte membrane (PEM) sandwiched between anode and cathode catalyst layer. In the case of hydrogen fuel, H 2 is oxidized at the anode and protons are transported through the PEM to the cathode. At the cathode, protons are combined with electrons flew through external circuit, reducing ambient oxygen to water. The operation principle of a PEMFC is illustrated in Figure 1. Perfluorosulfonic acid (PFSA) membranes such as Nafion are the most common and successful PEMs for low temperature PEMFCs (i.e., operation at 80 °C or below) and possess a high acidity, high conductivity (e.g., for Nafion 117, conductivity can be as high as ∼0.1 S cm -1 at 30 °C and 100% relative humidity [2] ), and high chemical and structural stability. [3] However, Nafion membrane must be fully hydrated in order to have the high proton conductivity and the stable operation of Nafion membrane based fuel cells because its proton conductivity decreases rapidly with the decrease in relative humidity (RH). [4] Thereby, the operation temperatures are limited to 80 °C or below under ambient pressure in order to maintain a high water content in the membrane. As proton transport requires an aqueous medium or water to maintain the high conductivity, water management is critical for the stable operation of Nafion based PEMFCs. In the case of transportation applications, water-based PEMFC stacks also require adequate heat management, e.g., large radiators/heat exchangers to extract the heat. Another critical issue for PFSA membrane based PEMFCs is the requirement of high purity H 2 as the Pt based electrocatalysts shows a very low resistance to the fuel The development of reliable power sources is important for the continuous operation of various electric equipment in unmanned aircraft and the field environment. Currently electric power delivery to such systems is mainly by battery packs. An alternative is to use fuel cells (FCs). FCs are electrochemical devices that are used to convert chemical energy of fuels such as hydrogen and methanol to electricity. Methanol is an attractive fuel because it is liquid at ambient temperature, has a much higher energy density than hydrogen and low reforming temperature (220-300 °C). Thus, integration of methanol steam reformers (MSRs) with FCs makes it possible to continuously produce electricity. The key challenge in such power system is the development of fuel cells which can be effe...

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Comparatative analysis on various reformers supplied with different fuels and integrated with high temperature PEM fuel cells

Cited by 13 publications

References 20 publications

Minimizing Heat Transfer Resistance in an Integrated Methanol Steam Reformer Designed Using Space-Filling Curves

Minimizing Heat Transfer Resistance in an Integrated Methanol Steam Reformer Designed Using Space-Filling Curves

Conceptual design of an integrated thermally self-sustained methanol steam reformer – High-temperature PEM fuel cell stack manportable power generator

High Temperature Polymer Electrolyte Membrane Fuel Cells for Integrated Fuel Cell – Methanol Reformer Power Systems: A Critical Review

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