On-board power generation for vehicular applications requires a compact, simplified and well-integrated fuel processor-fuel cell system. In the present paper, the integration of an ethanol reformer unit with a 50 kWe high temperature polymer electrolyte membrane (PEM) fuel cell is studied for potential automotive applications. A high-efficiency dual reformer system is used for on-board production of hydrogen from ethanol. Heat transfer equipment for recovery of water and effective utilization of waste heat has been incorporated into the integrated system. Detailed analysis using ASPEN simulations shows that gross system efficiencies of up to 39% can be achieved. Estimates of size, weight of the integrated system have been made to assess its suitability for application as auxiliary power units in automotive systems. © 2017 Elsevier Ltd

Sreenivas Jayanti

Department Of Chemical Engineering

P. Purnima

efficiency

Electrolytes

Ethanol

Fuel cells

Heat transfer

High temperature applications

Hybrid vehicles

Hydrogen production

Integrated control

Polyelectrolytes

Solid wastes

Waste heat

Waste heat utilization

Waste management

Automotive applications

FUEL REFORMING

HEAT TRANSFER EQUIPMENT

HIGH TEMPERATURE POLYMER ELECTROLYTE MEMBRANES

Hydrogen generations

INTEGRATED FUEL PROCESSORS

ON BOARD HYDROGEN GENERATIONS

Vehicular applications

Proton exchange membrane fuel cells (PEMFC)

Electric vehicle

Electrolyte

Energy efficiency

equipment

fuel cell

High temperature

Hydrogen

membrane

power generation

Simulation

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Applied Energy

Power required to run auxiliary systems on a passenger car, such as those for air conditioning and advanced vehicle control, reduces the driving range of a vehicle equipped with a hybrid drive train. Under practical driving conditions, a significant amount of additional energy is required at low power levels compared to the rated power of the drive unit. In the present study, we consider a fuel cell-battery drive train augmented by an on-board fuel (ethanol) processor to provide the motoring power requirements of a car. Using systematic driving cycle simulations that take account of power-to-weight, energy-to-weight and power-to-efficiency factors of on-board power sources under simulated load conditions, we show that a combination of steadily-operated compact ethanol reformer, a low-power battery continuously charged by excess reformer capacity and a high-power fuel cell powered by conservatively-used hydrogen from cylinder can increase the range of hybrid fuel cell drivetrains to about 750 km. Although the overall energy consumption of the three-way hybrid is more than that of fuel cell-battery hybrid, lesser use of stored hydrogen improves the fuel economy of the hybrid drivetrain. While the system complexity is increased, long-range distressed mode operation becomes feasible with the added fuel processor. © 2019 Hydrogen Energy Publications LLC

International Journal of Hydrogen Energy

Fuel processor-battery-fuel cell hybrid drivetrain for extended range operation of passenger vehicles

On-board reforming of liquid fuels is essential for improved driving range of fuel cell-powered vehicles. There is increasing demand for such vehicles to be fuelled from renewable energy sources. In the present paper, we propose an efficient reformer system for hydrogen production from ethanol. Reforming is an endothermic process, and high temperatures, well above the operating temperatures of PEM or equivalent fuel cells, are required for sufficient catalytic activity for reforming reactions. We use Co-Fe/ZnO catalyst to carry out the reforming at around 500 °C and a combustor of excess fuel as well as directly-fed ethanol to generate the high temperatures required for reforming. It is shown through simulations that introducing a second reformer to extract more hydrogen from the methane obtained from the first reformer improves the overall efficiency. ASPEN-based simulations show that the overall efficiency of an optimized dual reformer system can be as high as 48.47%. © 2016 Hydrogen Energy Publications LLC

A high-efficiency, auto-thermal system for on-board hydrogen production for low temperature PEM fuel cells using dual reforming of ethanol

An integrated configuration of a fuel cell and an auto-thermal ethanol reformer has been studied conceptually for high temperature (HT) and low temperature (LT) polymer electrolyte membrane fuel cells (PEMFCs) for a 5. kW, stand-alone power unit. It is found that the integrated reformer-HT fuel cell system can operate in an auto-thermal mode using a Co-Fe/Zn catalyst to reform aqueous ethanol at 500. °C to produce hydrogen with about 3% of CO which is tolerable for an HT-PEMFC operating at 200. °C. A simulation model developed for the integrated reformer-HT-PEMFC system shows that significant amount of excess heat is available at 700. °C. Using this excess heat, an integrated reformer-HT-LT-PEMFC power unit is designed which produces 15. kW of electrical power at an overall efficiency of 41% and a thermal efficiency of 80%. Since it has an integrated aqueous ethanol reformer, the fuel for the power unit can be stored in liquid form which makes it ideal for stand-alone power unit applications. © 2013 Elsevier Ltd.

A conceptual model of a high-efficiency, stand-alone power unit based on a fuel cell stack with an integrated auto-thermal ethanol reformer

A proper thermal management strategy is needed to maintain uniform temperature distribution and derive optimal performance in high temperature proton exchange membrane fuel cells (HT-PEMFC). In HT-PEMFCs, more than half of the chemical energy is converted into thermal energy during the electrochemical generation of electrical power. We investigate the viability of three heat removal strategies: (a) using cooling plates through which cathode air is passed in excess of stoichiometric requirement for the purpose of heat removal, (b) using forced convection partly in conjunction with cooling plates, and (c) using forced convection alone for heat removal. Calculations, partly done using computational fluid dynamics simulations, for a 1 kWe HT-PEMFC stack, which is suitable for scooter type of transport applications, show that a combination of excess stoichiometric factor and forced draft appears to provide the optimal strategy for thermal management of high temperature PEM fuel cells. With proper cooling strategy, the temperature variations within the cell may be reduced to about 20 K over most of the cell and to about 50 K in isolated spots. © 2012 Elsevier Ltd. All rights reserved.

Applied Thermal Engineering

Thermal management strategies for a 1 kWe stack of a high temperature proton exchange membrane fuel cell

A new approach to calculating endurance in electric flight and comparing fuel cells and batteries

Energy management of a plug-in fuel cell/battery hybrid vehicle with on-board fuel processing

Water neutrality and waste heat management in ethanol reformer - HTPEMFC integrated system for on-board hydrogen generation

Journal	Data powered by TypesetApplied Energy
Publisher	Data powered by TypesetElsevier Ltd
ISSN	03062619
Open Access	No