Modeling Study on the Performance of an Integrated APU Fed with Hydrocarbon Fuels

Abstract

The employment of H 2 in fuel cell (FCs) technologies could ensure significant advantages in terms of efficiency and environmental impact, representing thus an important alternative to the conventional energy production systems. As far as the actual lack of infrastructure for H 2 production, storage, and distribution is concerned, FCs fed with H 2 , produced by fossil fuel reforming to generate on-board vehicles at least auxiliary power, represent a valid and interesting alternative to overcome the actual unfavorable situation, waiting for further development of infrastructures. The present work deals with the analysis of a 5 kW e auxiliary power unit (APU) integrated with a fuel processor unit (FPU), based on oxidative steam reforming (OSR, with bleed air, BA) and related CO clean-up technologies, for the production of H 2 -rich fuel gas, which is fed to a PEM-FC stack. Using the results of a series of steady-state system simulations with Matlab/Simulink, the APU performance was analyzed in terms of FP and APU efficiency, specific power produced by the stack, and water balance, by considering different liquid hydrocarbon fuels (gasoline, light and heavy diesel) and compressed natural gas (CNG) as feed. A parametric sensitivity analysis concerning the effects of the variation of steam to carbon ratio (SCR) and the BA rate to OSR was also carried out. As the main obtained results, the APU performance in transforming the primary fuel in H 2 -rich gas was more efficient according to the higher H 2 to carbon ratio HCR of the feedstock. In fact, the APU net efficiency decreased with the following order: methane (27.8%) > gasoline (27.0%) > light diesel (26.5%) > heavy diesel (26.0%). The parametric sensitivity analysis revealed that with small SCR decrease and bleed air rate increase it was possible to improve the APU performance.

Performance evaluation and comparison of fuel processors integrated with PEM fuel cell based on steam or autothermal reforming and on CO preferential oxidation or selective methanation

“…To reduce the APU complexity, a single stage non-isothermal reactor (NI-WGS) reaching the thermodynamic equilibrium is assumed according to [61,104]: the higher inlet temperature (330°C) is chosen to boost-up kinetics and the lower outlet one (300°C) to obtain a CO residual concentration of 0.5%, considering the beneficial effect of extra water fed to reach a H 2 O/CO molar ratio of about 5 [42,43,63,77,78,102]. The temperature profile in the multifunctional NI-WGS micro-channel item (reactor and exchanger) is controlled through the water stream fed to the reformer.…”

“…The assumed reactors working temperatures are the optimized ones as reported in the literature [42][43][44][45]49,63,78,86,[100][101][102][103][104][105][106]. The S/C molar ratio is the optimized value (as resulted from a sensitivity analysis carried out in this study with the system simulation by varying S/C inside the literature range 2-4) capable to maximize the ratio of the H 2 rate over the water vaporization heat rate.…”

“…An overall APU power of 5 kW e net is assumed. Typical requirements of the APUs for trucks and passengers vehicles are, in fact, based on the delivery of 5 kW e net [14,15,[77][78][79][80][81][82][83][84][85][86].…”

Oxidative reforming of diesel fuel over LaCoO3 perovskite derived catalysts: Influence of perovskite synthesis method on catalyst properties and performance

“…(1)) and partial oxidation (Eq. (2)) reactions, is the most attractive process since it has the simplest system design, has an acceptably high energy effectiveness and provides the better response to dynamic changes [2][3][4][5][6][7].…”

Evaluation of Co, La, and Mn promoted Rh catalysts for autothermal reforming of commercial diesel: Aging and characterization

“…The fuel reformer provides the fuel cell with hydrogen, which in turn produces the electricity. The production of hydrogen via fuel reforming is a versatile hydrogen source since the problems connected with storage and availability of hydrogen is eliminated and the fuel is easily available in an already existing and well-developed infrastructure [11] It is also an advantage to use the propellant as hydrogen source to avoid having two different fuel tanks on the vehicle.…”