scholarly journals Selective CO Methanation in H2-Rich Gas for Household Fuel Cell Applications

Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2844 ◽  
Author(s):  
Panagiota Garbis ◽  
Andreas Jess
Keyword(s):  
Fuel Cell ◽  
Natural Gas ◽  
Fixed Bed ◽  
Cell System ◽  
Operating Conditions ◽  
Attractive Alternative ◽  
Inlet Temperature ◽  
Co2 Methanation ◽  
Co Methanation ◽  
Selective Co Methanation

Polymer electrolyte membrane fuel cells (PEMFCs) are often used for household applications, utilizing hydrogen produced from natural gas from the gas grid. The hydrogen is thereby produced by steam reforming of natural gas followed by a water gas shift (WGS) unit. The H2-rich gas contains besides CO2 small amounts of CO, which deactivates the catalyst used in the PEMFCs. Preferential oxidation has so far been a reliable process to reduce this concentration but valuable H2 is also partly converted. Selective CO methanation considered as an attractive alternative. However, CO2 methanation consuming the valuable H2 has to be minimized. The modelling of selective CO methanation in a household fuel cell system is presented. The simulation was conducted for single and two-stage adiabatic fixed bed reactors (in the latter case with intermediate cooling), and the best operating conditions to achieve the required residual CO content (100 ppm) were calculated. This was done by varying the gas inlet temperature as well as the mass of the catalyst. The feed gas represented a reformate gas downstream of a typical WGS reaction unit (0.5%–1% CO, 10%–25% CO2, and 5%–20% H2O (rest H2)).

scholarly journals Kinetics and Reactor Design Aspects of Selective Methanation of CO over a Ru/γ-Al2O3 Catalyst in CO2/H2 Rich Gases

Energies ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 469 ◽  
Author(s):  
Panagiota Garbis ◽  
Christoph Kern ◽  
Andreas Jess
Keyword(s):  
Polymer Electrolyte Membrane ◽  
Fixed Bed ◽  
Kinetic Equations ◽  
Fixed Bed Reactor ◽  
Water Gas Shift ◽  
Co2 Methanation ◽  
Co Methanation ◽  
Electrolyte Membrane ◽  
Selective Co Methanation ◽  
Water Gas

Polymer electrolyte membrane fuel cells (PEMFCs) for household applications utilize H2 produced from natural gas via steam reforming followed by a water gas shift (WGS) unit. The H2-rich gas contains CO2 and small amounts of CO, which is a poison for PEMFCs. Today, CO is mostly converted by addition of O2 and preferential oxidation, but H2 is then also partly oxidized. An alternative is selective CO methanation, studied in this work. CO2 methanation is then a highly unwanted reaction, consuming additional H2. The kinetics of CO methanation in CO2/H2 rich gases were studied with a home-made Ru catalyst in a fixed bed reactor at 1 bar and 160–240 °C. Both CO and CO2 methanation can be well described by a Langmuir Hinshelwood approach. The rate of CO2 methanation is slow compared to CO. CO2 is directly converted to methane, i.e., the indirect route via reverse water gas shift (WGS) and subsequent CO methanation could be excluded by the experimental data and in combination with kinetic considerations. Pore diffusion may affect the CO conversion (>200 °C). The kinetic equations were applied to model an adiabatic fixed bed methanation reactor of a fuel cell appliance.

Thermodynamic, exergetic, and thermoeconomic analyses of a 1-kW proton exchange membrane fuel cell system fueled by natural gas

Energy ◽  
2020 ◽  
pp. 119362
Author(s):  
Seok-Ho Seo ◽  
Si-Doek Oh ◽  
Jinwon Park ◽  
Hwanyeong Oh ◽  
Yoon-Young Choi ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Natural Gas ◽  
Proton Exchange Membrane ◽  
Cell System ◽  
Proton Exchange ◽  
Fuel Cell System ◽  
Exchange Membrane

Surge Prevention Techniques for a Turbocharged Solid Oxide Fuel Cell Hybrid System

2021 ◽  
Author(s):  
L. Mantelli ◽  
M. L. Ferrari ◽  
A. Traverso
Keyword(s):  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Rotational Speed ◽  
Pressure Ratio ◽  
High Energy ◽  
Cell System ◽  
Solid Oxide ◽  
Pollutant Emissions ◽  
Inlet Temperature ◽  
Oxide Fuel

Abstract Pressurized solid oxide fuel cell (SOFC) systems are one of the most promising technologies to achieve high energy conversion efficiencies and reduce pollutant emissions. The most common solution for pressurization is the integration with a micro gas turbine, a device capable of exploiting the residual energy of the exhaust gas to compress the fuel cell air intake and, at the same time, generating additional electrical power. The focus of this study is on an alternative layout, based on an automotive turbocharger, which has been more recently considered by the research community to improve cost effectiveness at small size (< 100 kW), despite reducing slightly the top achievable performance. Such turbocharged SOFC system poses two main challenges. On one side, the absence of an electrical generator does not allow the direct control of the rotational speed, which is determined by the power balance between turbine and compressor. On the other side, the presence of a large volume between compressor and turbine, due to the fuel cell stack, alters the dynamic behavior of the turbocharger during transients, increasing the risk of compressor surge. The pressure oscillations associated with such event are particularly detrimental for the system, because they could easily damage the materials of the fuel cells. The aim of this paper is to investigate different techniques to drive the operative point of the compressor far from the surge condition when needed, reducing the risks related to transients and increasing its reliability. By means of a system dynamic model, developed using the TRANSEO simulation tool by TPG, the effect of different anti-surge solutions is simulated: (i) intake air conditioning, (ii) water spray at compressor inlet, (iii) air bleed and recirculation, and (iv) installation of an ejector at the compressor intake. The pressurized fuel cell system is simulated with two different control strategies, i.e. constant fuel mass flow and constant turbine inlet temperature. Different solutions are evaluated based on surge margin behavior, both in the short and long terms, but also monitoring other relevant physical quantities of the system, such as compressor pressure ratio and turbocharger rotational speed.

Experimental and Theoretical Performance Analysis of a High Temperature PEM Fuel Cell Fed With LPG Using a Compact Steam Reformer

2011 ◽  
Author(s):  
Nicola Zuliani ◽  
Rodolfo Taccani ◽  
Robert Radu
Keyword(s):  
High Temperature ◽  
Fuel Cell ◽  
Cell System ◽  
Operating Conditions ◽  
Steam Reformer ◽  
Fuel Cell Performance ◽  
Fuel Processor ◽  
Balance Of Plant ◽  
Energy Balances ◽  
High Temperature Pem

High temperature PEM (HTPEM) fuel cell based on polybenzimidazole polymer (PBI) and phosphoric acid, can be operated at temperature between 120°C and 180°C. Reactants humidification is not required and CO content up to 1% in fuel can be tolerated, affecting only marginally performance. This is what makes HTPEM fuel cells very attractive, as low quality reformed hydrogen can be used and water management problems are avoided. This paper aims to present the preliminary experimental results obtained on a HTPEM fuel cell fed with LPG using a compact steam reformer. The analysis focus on the reformer start up transient, on the influence of the steam to carbon ratio on reformate CO content and on the single fuel cell performance at different operating conditions. By analyzing the mass and energy balances of the fuel processor, fuel cell system, and balance-of-plant, a previously developed system simulation model has been used to provide critical assessment on the conversion efficiency for a 1 kWel system. The current study attempts to extend the previously published analyses of integrated HTPEM fuel cell systems.

Experimental Results of a PEM System Operated on Hydrogen and Reformate

2008 ◽  
Vol 5 (1) ◽  
Author(s):  
M. Minutillo ◽  
E. Jannelli ◽  
F. Tunzio
Keyword(s):  
Fuel Cell ◽  
Natural Gas ◽  
Large Scale ◽  
Pem Fuel Cell ◽  
Proton Exchange ◽  
Operating Conditions ◽  
Cell Performance ◽  
Pure Hydrogen ◽  
Test Bed ◽  
Fuel Cell Performance

The main objective of this study is to evaluate the performance of a proton exchange membrane (PEM) fuel cell generator operating for residential applications. The fuel cell performance has been evaluated using the test bed of the University of Cassino. The experimental activity has been focused to evaluate the performance in different operating conditions: stack temperature, feeding mode, and fuel composition. In order to use PEM fuel cell technology on a large scale, for an electric power distributed generation, it could be necessary to feed fuel cells with conventional fuel, such as natural gas, to generate hydrogen in situ because currently the infrastructure for the distribution of hydrogen is almost nonexistent. Therefore, the fuel cell performance has been evaluated both using pure hydrogen and reformate gas produced by a natural gas reforming system.

Theoretical Analysis on the Autothermal Reforming Process of Ethanol as Fuel for a Proton Exchange Membrane Fuel Cell System

2006 ◽  
Vol 4 (4) ◽  
pp. 468-473 ◽  
Author(s):  
Alessandra Perna
Keyword(s):  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Pem Fuel Cell ◽  
Cell System ◽  
Autothermal Reforming ◽  
Proton Exchange ◽  
Operating Conditions ◽  
Hydrogen Yield ◽  
Fuel Cell System ◽  
Exchange Membrane

The purpose of this work is to investigate, by a thermodynamic analysis, the effects of the process variables on the performance of an autothermal reforming (ATR)-based fuel processor, operating on ethanol as fuel, integrated into an overall proton exchange membrane (PEM) fuel cell system. This analysis has been carried out finding the better operating conditions to maximize hydrogen yield and to minimize CO carbon monoxide production. In order to evaluate the overall efficiency of the system, PEM fuel cell operations have been analyzed by an available parametric model.

scholarly journals Fuel Cell designing with optimal high speed air compressor

2021 ◽  
pp. 29-38
Author(s):  
Nabeel Ahsan ◽  
Mahrukh Mehmood ◽  
Asad A. Zaidi
Keyword(s):  
Fuel Cell ◽  
High Speed ◽  
Proton Exchange Membrane ◽  
Cell System ◽  
Proton Exchange ◽  
Operating Conditions ◽  
Air Compressor ◽  
Different Types ◽  
Input Parameters ◽  
Turbo Compressor

This paper discusses different air management technologies for fuel cell systems. Two different types of compressors are analyzed for Proton-exchange membrane fuel cells (PEMFC). Some important criteria are analyzed thoroughly for the selection of turbo compressor among different types of compressors illustrated with the help of matrix representations. The impacts of various input parameters for Fuel Cell (FC) are also explained thoroughly. Later the numerical modeling of an automobile fuel cell system using a high speed turbo-compressor for air supply is explained. The numerical model incorporates the important input parameters related with air and hydrogen. It also performed energy and mass balances across different components such as pump, fan, heat-exchanger, air compressor and also keeps in consideration the pressure drop across the flow pipes and various mechanical parts. The model is solved to obtain the characteristics of the FC system at different operating conditions. Therefore, it can be concluded that the high speed turbo compressor with a turbo-expander can have significant effects on the overall system power and efficiency.

Residential Experience with Proton Exchange Membrane Fuel Cell Systems for Combined Heat and Power

2005 ◽  
Vol 2 (4) ◽  
pp. 263-267 ◽  
Author(s):  
Darrell D. Massie ◽  
Daisie D. Boettner ◽  
Cheryl A. Massie
Keyword(s):  
Fuel Cell ◽  
Natural Gas ◽  
Heat Recovery ◽  
Proton Exchange Membrane ◽  
Waste Heat ◽  
Cell System ◽  
Proton Exchange ◽  
Fuel Cell System ◽  
Cell Systems ◽  
Exchange Membrane

As part of a one-year Department of Defense demonstration project, proton exchange membrane fuel cell systems have been installed at three residences to provide electrical power and waste heat for domestic hot water and space heating. The 5kW capacity fuel cells operate on reformed natural gas. These systems operate at preset levels providing power to the residence and to the utility grid. During grid outages, the residential power source is disconnected from the grid and the fuel cell system operates in standby mode to provide power to critical loads in the residence. This paper describes lessons learned from installation and operation of these fuel cell systems in existing residences. Issues associated with installation of a fuel cell system for combined heat and power focus primarily on fuel cell siting, plumbing external to the fuel cell unit required to support heat recovery, and line connections between the fuel cell unit and the home interior for natural gas, water, electricity, and communications. Operational considerations of the fuel cell system are linked to heat recovery system design and conditions required for adequate flow of natural gas, air, water, and system communications. Based on actual experience with these systems in a residential setting, proper system design, component installation, and sustainment of required flows are essential for the fuel cell system to provide reliable power and waste heat.

scholarly journals Thermoeconomic Optimization of a Hybrid Photovoltaic-Solid Oxide Fuel Cell System for Decentralized Application

2019 ◽  
Vol 9 (24) ◽  
pp. 5450
Author(s):  
Alexandros Arsalis ◽  
George E. Georghiou
Keyword(s):  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Cell System ◽  
Solid Oxide ◽  
Small Scale ◽  
Inlet Temperature ◽  
Oxide Fuel ◽  
Optimization Strategy ◽  
Commercial Building ◽  
Autonomous Operation

A small-scale, decentralized hybrid system is proposed for autonomous operation in a commercial building (small hotel). The study attempts to provide a potential solution, which will be attractive both in terms of efficiency and economics. The proposed configuration consists of the photovoltaic (PV) and solid oxide fuel cell (SOFC) subsystems. The fuel cell subsystem is fueled with natural gas. The SOFC stack model is validated using literature data. A thermoeconomic optimization strategy, based on a genetic algorithm approach, is applied to the developed model to minimize the system lifecycle cost (LCC). Four decision variables are identified and chosen for the thermoeconomic optimization: temperature at anode inlet, temperature at cathode inlet, temperature at combustor exit, and steam-to-carbon ratio. The total capacity at design conditions is 70 and 137.5 kWe, for the PV and SOFC subsystems, respectively. After the application of the optimization process, the LCC is reduced from 1,203,266 to 1,049,984 USD. This improvement is due to the reduction of fuel consumed by the system, which also results in an increase of the average net electrical efficiency from 29.2 to 35.4%. The thermoeconomic optimization of the system increases its future viability and energy market penetration potential.

Active, Reactive and Harmonic compensation control of grid interfaced fuel cell system

2012 ◽  
Vol 13 (4) ◽  
Author(s):  
Gitanjali Mehta ◽  
S. P. Singh ◽  
Ram Dayal Patidar
Keyword(s):  
Fuel Cell ◽  
Reactive Power ◽  
Active Power Filter ◽  
Cell System ◽  
Active Power ◽  
Operating Conditions ◽  
Voltage Source ◽  
Filter Function ◽  
Load Current ◽  
Power Filter

Abstract This paper presents the modelling and control of grid interfaced fuel cell distributed generation system with embedded active filter function. The features of active power filter have been incorporated in the control circuit of the current controlled-voltage source inverter interfacing the fuel cell to the grid. Thus the same inverter is utilised to inject power generated from fuel cell source to the grid and to act as shunt active power filter to compensate for load current harmonics, load reactive power demand and load current imbalance. Thus, after compensation, the grid current is sinusoidal and in-phase with grid voltage. Simulation in MATAB and experimentation using DSP is carried out to verify the operation and the control principle. The results are obtained for different operating conditions with varying load demands to prove the effectiveness of the entire system.

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