The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Stefania Specchia - One of the best experts on this subject based on the ideXlab platform.
-
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
Applied Energy, 2015Co-Authors: Giuliana Ercolino, Muhammad Arsala Ashraf, Vito Specchia, Stefania SpecchiaAbstract:The performances of four different auxiliary power unit (APU) schemes, based on a 5kWe net proton exchange membrane Fuel cell (PEM-FC) stack, are evaluated and compared. The Fuel Processor section of each APU is characterized by a reformer (autothermal ATR or steam SR), a non-isothermal water gas shift (NI-WGS) reactor and a final syngas catalytic clean-up step: the CO preferential oxidation (PROX) reactor or the CO selective methanation (SMET) one. Furthermore, three hydrocarbon Fuels, the most commonly found in service stations (gasoline, light diesel oil and natural gas) are considered as primary Fuels. The comparison is carried out examining the results obtained by a series of steady-state system simulations in Aspen Plus® of the four different APU schemes by varying the fed Fuel. From the calculated data, the performance of CO-PROX is not very different compared to that of the CO-SMET, but the performance of the SR based APUs is higher than the scheme of the ATR based APUs. The most promising APU scheme with respect to an overall performance target is the scheme fed with natural gas and characterized by a Fuel Processor chain consisting of SR, NI-WGS and CO-SMET reactors. This processing reactors scheme together with the Fuel cell section, notwithstanding having practically the same energy efficiency of the scheme with SR, NI-WGS and CO-PROX reactors, ensures a less complex scheme, higher hydrogen concentration in the syngas, lower air mass rate consumption, the absence of nitrogen in the syngas and higher potential power of the stack anode exhaust. The stack anode exhaust, in fact, is recycled to the Fuel Processor section, thanks to the presence of methane produced in the final clean-up methanation reactor.
-
A micro-structured 5 kW complete Fuel Processor for iso-octane as hydrogen supply system for mobile auxiliary power units Part II—Development of water-gas shift and preferential oxidation catalysts reactors and assembly of the Fuel Processor
Chemical Engineering Journal, 2008Co-Authors: Gunther Kolb, Chritopher Galletti, Tobias Baier, Jochen Schürer, David Tiemann, Giacomo Germani, Stefania Specchia, Athanassios Ziogas, Yves SchuurmanAbstract:Abstract Microstructured reactors for water–gas shift and the preferential oxidation of carbon monoxide were developed for a Fuel processing/Fuel cell system running on iso-octane and designed for an electrical power output of 5 kW el . The target application was an automotive auxiliary power unit (APU). The work covered both catalyst and reactor development. A platinum/ceria catalyst was applied for water–gas shift, while platinum on zeolite/alumina carrier served as catalyst for preferential oxidation. These catalysts were introduced into the final full size prototype reactors, which were constructed from microstructured stainless steel foils. Testing in a pilot scale test rig revealed conversion close to the thermodynamic equilibrium for the water–gas shift reactors at a WHSV range of 17–41 Ndm 3 /(h g cat ). The preferential oxidation, which was performed at higher WHSV in the range of 48–98 Ndm 3 /(h g cat ) revealed up to 90% conversion in a first stage, while in the second stage reactor the carbon monoxide content of the reformate was decreased to less than 50 ppm. The reactors were then incorporated into a complete bread-board Fuel Processor of 5 kW el power equivalent, which comprised also of an autothermal reformer reactor. The Fuel Processor was operated at a steam to carbon ratio of 3.3 and an oxygen to carbon ratio of 0.67. Under these conditions, it converted the iso-octane feed completely to purified reformate with an overall efficiency of 74%.
-
diesel Fuel Processor for pem Fuel cells two possible alternatives atr versus sr
Journal of Power Sources, 2006Co-Authors: A Cutillo, Stefania Specchia, Guido Saracco, Massimiliano Antonini, Vito SpecchiaAbstract:Abstract There are large efforts in exploring the on-board reforming technologies, which would avoid the actual lack of hydrogen infrastructure and related safety issues. From this view point, the present work deals with the comparison between two different 10 kW e Fuel Processors (FP) systems for the production of hydrogen-rich Fuel gas starting from diesel oil, based respectively on autothermal (ATR) and steam-reforming (SR) process and related CO clean-up technologies; the obtained hydrogen rich gas is fed to the PEMFC stack of an auxiliary power unit (APU). Based on a series of simulations with Matlab/Simulink, the two systems were compared in terms of FP and APU efficiency, hydrogen concentration fed to the FC, water balance and process scheme complexity. Notwithstanding a slightly higher process scheme complexity and a slightly more difficult water recovery, the FP based on the SR scheme, as compared to the ATR one, shows higher efficiency and larger hydrogen concentration for the stream fed to the PEMFC anode, which represent key issues for auxiliary power generation based on FCs as compared, e.g. to alternators.
-
biofeat biodiesel Fuel Processor for a vehicle Fuel cell auxiliary power unit study of the feed system
Journal of Power Sources, 2005Co-Authors: Mauro Sgroi, Gianluca Bollito, Guido Saracco, Stefania SpecchiaAbstract:Abstract An integrated auxiliary power unit (APU) based on a 10 kW e integrated biodiesel Fuel Processor has been designed and is being developed. Auto-thermal reforming (ATR) and thermal cracking (TC) were considered for converting the Fuel into a hydrogen-rich gas suitable for PEM Fuel cells. The Fuel Processor includes also a gas clean-up system that will reduce the carbon monoxide in the primary Processor exit gas to below 10 ppm via a new heat-integrated CO clean-up unit, based on the assembly of catalytic heat exchange plates, so as to meet the operational requirements of a PEMFC stack. This article is devoted to the study and selection of the proper feed strategy for the primary Fuel Processor. Different pre-treatment and feed alternatives (e.g. based on nozzles or simple coils) were devised and tested for the ATR Processors, which turned out to be the preferred primary processing route. A nozzle-based strategy was finally selected along with special recommendations about the constituent materials and the operating procedures to be adopted to avoid coking and nozzle corrosion as well as to allow a wide turn down ratio.
-
conceptual design and selection of a biodiesel Fuel Processor for a vehicle Fuel cell auxiliary power unit
Journal of Power Sources, 2005Co-Authors: Stefania Specchia, F W A Tillemans, P F Van Den Oosterkamp, Guido SaraccoAbstract:Abstract Within the European project BIOFEAT (biodiesel Fuel Processor for a Fuel cell auxiliary power unit for a vehicle), a complete modular 10 kWe biodiesel Fuel Processor capable of feeding a PEMFC will be developed, built and tested to generate electricity for a vehicle auxiliary power unit (APU). Tail pipe emissions reduction, increased use of renewable Fuels, increase of hydrogen-Fuel economy and efficient supply of present and future APU for road vehicles are the main project goals. Biodiesel is the chosen feedstock because it is a completely natural and thus renewable Fuel. Three Fuel processing options were taken into account at a conceptual design level and compared for hydrogen production: (i) autothermal reformer (ATR) with high and low temperature shift (HTS/LTS) reactors; (ii) autothermal reformer (ATR) with a single medium temperature shift (MTS) reactor; (iii) thermal cracker (TC) with high and low temperature shift (HTS/LTS) reactors. Based on a number of simulations (with the AspenPlus® software), the best operating conditions were determined (steam-to-carbon and O2/C ratios, operating temperatures and pressures) for each process alternative. The selection of the preferential Fuel processing option was consequently carried out, based on a number of criteria (efficiency, complexity, compactness, safety, controllability, emissions, etc.); the ATR with both HTS and LTS reactors shows the most promising results, with a net electrical efficiency of 29% (LHV).
Yong Wang - One of the best experts on this subject based on the ideXlab platform.
-
a review of recent advances in numerical simulations of microscale Fuel Processor for hydrogen production
Journal of Power Sources, 2015Co-Authors: Jamelyn D Holladay, Yong WangAbstract:Microscale (<5 W) reformers for hydrogen production have been investigated for over a decade. These devices are intended to provide hydrogen for small Fuel cells. Due to the reformer's small size, numerical simulations are critical to understand heat and mass transfer phenomena occurring in the systems and help guide the further improvements. This paper reviews the development of the numerical codes and details the reaction equations used. The majority of the devices utilized methanol as the Fuel due to methanol's low reforming temperature and high conversion, although, there are several methane Fueled systems. The increased computational power and more complex codes have led to improved accuracy of numerical simulations. Initial models focused on the reformer, while more recently, the simulations began including other unit operations such as vaporizers, inlet manifolds, and combustors. These codes are critical for developing the next generation systems. The systems reviewed included plate reactors, microchannel reactors, and annulus reactors for both wash-coated and packed bed systems.
-
cr free fe based metal oxide catalysts for high temperature water gas shift reaction of Fuel Processor using lpg
Catalysis Today, 2009Co-Authors: Joon Yeob Lee, Dae Won Lee, Kwan Young Lee, Yong WangAbstract:Abstract The goal of this study was to identify the most suitable chromium-free iron-based catalysts for the HTS (high temperature shift) reaction of a Fuel Processor using LPG. Hexavalent chromium (Cr6+) in the commercial HTS catalyst has been regarded as hazardous material. We selected Ni and Co as the substitution for chromium in the Fe-based HTS catalyst and investigated the HTS activities of these Cr-free catalysts at LPG reformate condition. Cr-free Fe-based catalysts which contain Ni, Zn, or Co instead of Cr were prepared by coprecipitation method and the performance of the catalysts in HTS was evaluated under gas mixture conditions (42% H2, 10% CO, 37% H2O, 8% CO2, and 3% CH4; R (reduction factor): about 1.2) similar to the gases from steam reforming of LPG (100% conversion at steam/carbon ratio = 3), which is higher than R (under 1) of typically studied LNG reformate condition. Among the prepared Cr-free Fe-based catalysts, the 5 wt%-Co/Fe/20 wt%-Ni and 5 wt%-Zn/Fe/20 wt%-Ni catalysts showed good catalytic activity under this reaction condition simulating LPG reformate gas.
-
development of highly active pd zno al2o3 catalysts for microscale Fuel Processor applications
Chemical Engineering & Technology, 2005Co-Authors: Gordon Xia, Robert A Dagle, Jamie D Holladay, Evan O Jones, Yong WangAbstract:A series of alumina supported Pd-ZnO catalysts were synthesized and studied for methanol steam reforming. Pd loading and Pd/Zn ratio were optimized to improve catalyst activities. Among all the catalysts studied, the catalyst with a Pd loading of 8.9 wt % and a Pd/Zn molar ratio of 0.38 exhibited the highest methanol conversion and the lowest CO selectivity. The significantly improved Pd-ZnO/Al 2 O 3 catalyst activity was one of the main factors improving the efficiency of a microscale Fuel Processor from 9 % to 15 %.
-
development of a soldier portable Fuel cell power system part i a bread board methanol Fuel Processor
Journal of Power Sources, 2002Co-Authors: Daniel R Palo, Yong Wang, Jamelyn D Holladay, Robert Rozmiarek, Consuelo E Guzmanleong, Yahuei Chin, Robert A Dagle, Eddie G BakerAbstract:Abstract A 15-We portable power system is being developed for the US Army that consists of a hydrogen-generating Fuel reformer coupled to a proton-exchange membrane Fuel cell. In the first phase of this project, a methanol steam reformer system was developed and demonstrated. The reformer system included a combustor, two vaporizers, and a steam reforming reactor. The device was demonstrated as a thermally independent unit over the range of 14–80 Wt output. Assuming a 14-day mission life and an ultimate 1-kg Fuel Processor/Fuel cell assembly, a base case was chosen to illustrate the expected system performance. Operating at 13 We, the system yielded a Fuel Processor efficiency of 45% (LHV of H2 out/LHV of Fuel in) and an estimated net efficiency of 22% (assuming a Fuel cell efficiency of 48%). The resulting energy density of 720 Wh/kg is several times the energy density of the best lithium-ion batteries. Some immediate areas of improvement in thermal management also have been identified, and an integrated Fuel Processor is under development. The final system will be a hybrid, containing a Fuel reformer, a Fuel cell, and a rechargeable battery. The battery will provide power for start-up and added capacity for times of peak power demand.
-
microchannel reactors for Fuel processing applications i water gas shift reactor
Chemical Engineering Science, 1999Co-Authors: A Y Tonkovich, Yong Wang, Jennifer L Zilka, Mike Lamont, Robert S WegengAbstract:Abstract The water gas shift reactor is one of the critical components of a multi-reactor Fuel processing system that supports distributed energy production through the use of a Fuel cell. The water gas shift reaction converts carbon monoxide (produced in the primary conversion stage of the Fuel Processor) and water to carbon dioxide and hydrogen. The water gas shift reaction has slow observed kinetics, with multiple-second contact times, which are cited in fixed-bed reactors. The intrinsic reaction kinetics, however, are measured to be fast, with millisecond contact times, which enables miniaturized deployment in a microchannel reactor. Microchannel reactors reduce heat and mass transport limitations for reactions, and thus facilitate exploiting fast intrinsic reaction kinetics, ie. high effectiveness factors. The implications of this work suggest that a water gas shift reactor for a Fuel Processor (and other applications) will approach sizes one-to-two orders of magnitude smaller than conventional processing hardware.
Wang Lai Yoon - One of the best experts on this subject based on the ideXlab platform.
-
genuine design of compact natural gas Fuel Processor for 1 kwe class residential proton exchange membrane Fuel cell systems
Fuel Processing Technology, 2014Co-Authors: Un Ho Jung, Woohyun Kim, Kee Young Koo, Wang Lai YoonAbstract:Abstract A newly designed compact natural gas Fuel Processor, namely KIER prototype III, for 1-kW e class residential proton exchange membrane (PEM) Fuel cell systems has been developed. The system satisfies the main prerequisites for viable application such as 80% thermal efficiency on the basis of lower heating value at full load as well as CO concentration at PrOx exit less than 10 ppm on a dry basis by integrating internal heat exchange network between heat sources, e.g. burner flame, flue gas and reformed gas from reformer exit, and sinks, e.g. water, feed gas and air. The total system volume including insulation is 13.5 L and also the response time at full load appeared to be less than 50 min. This work mainly describes the design strategies and the effects of independent parameters, e.g. SMR exit temperature and turn-down ratio, upon the response changes (carbon conversion and thermal efficiency). To develop an effective heat exchange network of a Fuel Processor, a commercial process simulation software package, Aspen Plus, has been used. Based on the simulation results of the conceptual design, a coaxial tubular Fuel Processor has been developed. Besides, the excellence of the thermally integrated system of the developed Fuel Processor is verified by comparing its actual operation data with the simulation results.
-
development of compact Fuel Processor for 2 kw class residential pemfcs
Journal of Power Sources, 2006Co-Authors: Yutaek Seo, Jin Hyeok Jeong, Dong Joo Seo, Wang Lai YoonAbstract:Korea Institute of Energy Research (KIER) has been developing a novel Fuel processing system to provide hydrogen rich gas to residential polymer electrolyte membrane Fuel cells (PEMFCs) cogeneration system. For the effective design of a compact hydrogen production system, the unit processes of steam reforming, high and low temperature water gas shift, steam generator and internal heat exchangers are thermally and physically integrated into a packaged hardware system. Several prototypes are under development and the prototype I Fuel Processor showed thermal efficiency of 73% as a HHV basis with methane conversion of 81%. Recently tested prototype II has been shown the improved performance of thermal efficiency of 76% with methane conversion of 83%. In both prototypes, two-stage PrOx reactors reduce CO concentration less than 10 ppm, which is the prerequisite CO limit condition of product gas for the PEMFCs stack. After confirming the initial performance of prototype I Fuel Processor, it is coupled with PEMFC single cell to test the durability and demonstrated that the Fuel Processor is operated for 3 days successfully without any failure of Fuel cell voltage. Prototype II Fuel Processor also showed stable performance during the durability test.
-
Design of an integrated Fuel Processor for residential PEMFCs applications
Journal of Power Sources, 2006Co-Authors: Jin Hyeok Jeong, Wang Lai YoonAbstract:KIER has been developing a novel Fuel processing system to provide hydrogen rich gas to residential PEMFCs system. For the effective design of a compact hydrogen production system, each unit process for steam reforming and water gas shift, has a steam generator and internal heat exchangers which are thermally and physically integrated into a single packaged hardware system. The newly designed Fuel Processor (prototype II) showed a thermal efficiency of 78% as a HHV basis with methane conversion of 89%. The preferential oxidation unit with two staged cascade reactors, reduces, the CO concentration to below 10 ppm without complicated temperature control hardware, which is the prerequisite CO limit for the PEMFC stack. After we achieve the initial performance of the Fuel Processor, partial load operation was carried out to test the performance and reliability of the Fuel Processor at various loads. The stability of the Fuel Processor was also demonstrated for three successive days with a stable composition of product gas and thermal efficiency. The CO concentration remained below 10 ppm during the test period and confirmed the stable performance of the two-stage PrOx reactors.
-
Development of a micro Fuel Processor for PEMFCs
Electrochimica Acta, 2004Co-Authors: Dong Joo Seo, Wang Lai Yoon, Young-gi Yoon, Seok-hee Park, Gu-gon Park, Chang-soo KimAbstract:Abstract It is essential to make hydrogen supplying units with high energy density and compact size in order to apply polymer electrolyte membrane Fuel cells (PEMFCs) for portable devices. The small and lightweight Fuel Processor can be a competitive hydrogen supplying unit for this type of Fuel cells. Microchannels were patterned on the metal sheets and fabricated to make a reformer and vaporizer unit. Catalyst was deposited inside the microchannel of a reformer unit. Electrical heaters provide heat for the endothermic reaction and the vaporization of liquid Fuel. A vaporizer and a reformer unit were connected serially to make a proto-type microreactor. The dimensions of the reformer and vaporizer unit excluding fittings were about 70 mm × 40 mm × 30 mm, respectively. The steam reforming of methanol was conducted with the microreactor. The performance of the microreactor was investigated at various operating conditions. The developed Fuel Processor generates enough hydrogen for power output of 10 W.
-
selective oxidation of carbon monoxide in hydrogen rich stream over cu ce γ al2o3 catalysts promoted with cobalt in a Fuel Processor for proton exchange membrane Fuel cells
Journal of Power Sources, 2004Co-Authors: Jongwon Park, Jin Hyeok Jeong, Wang Lai Yoon, Young Woo RheeAbstract:Abstract Cu-Ce/γ-Al 2 O 3 catalysts promoted with cobalt are tested for the low-temperature selective oxidation of carbon monoxide (CO) in excess hydrogen, as produced by a Fuel Processor for proton exchange membrane Fuel cells (PEMFCs). A small addition (0.2 wt.%) of Co to Cu-Ce/γ-Al 2 O 3 leads to a large increase in the activity for selective CO oxidation. When either CO 2 (13 vol.%) or H 2 O (10 vol.%) is present in the reformed gas feed, both Cu-Ce/γ-Al 2 O 3 and Cu-Ce-Co/γ-Al 2 O 3 show a decrease in CO oxidation activity at low temperatures, especially, under 200 °C. Compared with Cu-Ce/γ-Al 2 O 3 , however, Cu-Ce-Co/γ-Al 2 O 3 gives higher resistance to CO 2 and H 2 O. There also exists a temperature window at 210–225 °C that corresponds to the conversion of 99.9% CO. From stability tests and temperature-programmed (TPD) desorption studies of CO 2 /H 2 O, it is concluded that the main cause for the decrease in catalytic activity with CO 2 and H 2 O in the feed is due to competitive adsorption of CO and CO 2 as well as to the blockage of the active sites by water vapor at low reaction temperatures.
Sangho Yoon - One of the best experts on this subject based on the ideXlab platform.
-
A diesel Fuel Processor for stable operation of solid oxide Fuel cells system: II. Integrated diesel Fuel Processor for the operation of solid oxide Fuel cells
International Journal of Hydrogen Energy, 2012Co-Authors: Sangho Yoon, Joongmyeon Bae, Sangho Lee, Thang V. Pham, Sai P. KatikaneniAbstract:Abstract Post-reforming experimental results for the complete removal of light hydrocarbons from diesel reformate are introduced in part I. In part II of the paper, an integrated diesel Fuel Processor is investigated for the stable operation of SOFCs. Several post-reforming Processors have been operated to suppress both sulfur poisoning and carbon deposition on the anode catalyst. The integrated diesel Fuel Processor is composed of an autothermal reformer, a desulfurizer, and a post-reformer. The autothermal reforming section in the integrated diesel Fuel Processor effectively decomposes aromatics, and converts Fuel into H2-rich syngas. The subsequent desulfurizer removes sulfur-containing compounds present in the diesel reformate. Finally, the post-reformer completely removes the light hydrocarbons, which are carbon precursors, in the diesel reformate. We successfully operate the diesel reformer, desulfurizer, and post-reformer as microreactors for about 2500 h in an integrated mode. The degradation rate of the overall reforming performance is negligible for the 2000 h, and light hydrocarbons and sulfur-containing compounds are completely removed from the diesel reformate.
-
a diesel Fuel Processor for stable operation of solid oxide Fuel cells system i introduction to post reforming for the diesel Fuel Processor
Catalysis Today, 2010Co-Authors: Sangho Yoon, Joongmyeon BaeAbstract:Abstract In this paper, a new concept of diesel Fuel processing is introduced for the stable operation of solid oxide Fuel cells (SOFCs). High temperature operation of SOFCs can lead to the capability of internal reforming with Fuel flexibility. SOFCs can directly use CH 4 and CO as Fuels given sufficient steam feeds due to catalytic reaction on the SOFC anode. However, heavier hydrocarbons than CH 4 , such as ethylene, ethane, propane, etc., induce carbon deposition on the Ni-based anode of SOFCs. In the case of an ethylene steam reforming reaction on the Ni-based catalyst, the rate of carbon deposition is faster than it is when hydrocarbons, including aromatics, are used. Hence, the removal of light hydrocarbons (over C 1 -hydrocarbons), especially ethylene, with the reformate gases of heavy hydrocarbons (diesel, gasoline, kerosene, and JP-8) is important for stable operation of SOFCs. A new methodology, called the “post-reformer”, is introduced for removing the light hydrocarbons (over C 1 -hydrocarbons) with the reformate gas stream. The CGO-Ru (3.0 wt.%) catalyst was selected as the post-reforming catalyst because it shows high selectivity for removing light hydrocarbons (over C 1 -hydrocarbons) and achieving the high reforming efficiency. The diesel reformer and post-reformer are continuously operated for about 200 h in an integrated mode. The reforming performance did not degrade, and light hydrocarbons (over C 1 -hydrocarbons) in the diesel reformate were completely removed.
-
self sustained operation of a kwe class kerosene reforming Processor for solid oxide Fuel cells
Journal of Power Sources, 2009Co-Authors: Sangho Yoon, Joongmyeon Bae, Sunyoung Kim, Youngsung YooAbstract:Abstract In this paper, Fuel-processing technologies are developed for application in residential power generation (RPG) in solid oxide Fuel cells (SOFCs). Kerosene is selected as the Fuel because of its high hydrogen density and because of the established infrastructure that already exists in South Korea. A kerosene Fuel Processor with two different reaction stages, autothermal reforming (ATR) and adsorptive desulfurization reactions, is developed for SOFC operations. ATR is suited to the reforming of liquid hydrocarbon Fuels because oxygen-aided reactions can break the aromatics in the Fuel and steam can suppress carbon deposition during the reforming reaction. ATR can also be implemented as a self-sustaining reactor due to the exothermicity of the reaction. The kW e self-sustained kerosene Fuel Processor, including the desulfurizer, operates for about 250 h in this study. This Fuel Processor does not require a heat exchanger between the ATR reactor and the desulfurizer or electric equipment for heat supply and Fuel or water vaporization because a suitable temperature of the ATR reformate is reached for H 2 S adsorption on the ZnO catalyst beds in desulfurizer. Although the CH 4 concentration in the reformate gas of the Fuel Processor is higher due to the lower temperature of ATR tail gas, SOFCs can directly use CH 4 as a Fuel with the addition of sufficient steam feeds (H 2 O/CH 4 ≥ 1.5), in contrast to low-temperature Fuel cells. The reforming efficiency of the Fuel Processor is about 60%, and the desulfurizer removed H 2 S to a sufficient level to allow for the operation of SOFCs.
Guido Saracco - One of the best experts on this subject based on the ideXlab platform.
-
diesel Fuel Processor for pem Fuel cells two possible alternatives atr versus sr
Journal of Power Sources, 2006Co-Authors: A Cutillo, Stefania Specchia, Guido Saracco, Massimiliano Antonini, Vito SpecchiaAbstract:Abstract There are large efforts in exploring the on-board reforming technologies, which would avoid the actual lack of hydrogen infrastructure and related safety issues. From this view point, the present work deals with the comparison between two different 10 kW e Fuel Processors (FP) systems for the production of hydrogen-rich Fuel gas starting from diesel oil, based respectively on autothermal (ATR) and steam-reforming (SR) process and related CO clean-up technologies; the obtained hydrogen rich gas is fed to the PEMFC stack of an auxiliary power unit (APU). Based on a series of simulations with Matlab/Simulink, the two systems were compared in terms of FP and APU efficiency, hydrogen concentration fed to the FC, water balance and process scheme complexity. Notwithstanding a slightly higher process scheme complexity and a slightly more difficult water recovery, the FP based on the SR scheme, as compared to the ATR one, shows higher efficiency and larger hydrogen concentration for the stream fed to the PEMFC anode, which represent key issues for auxiliary power generation based on FCs as compared, e.g. to alternators.
-
biofeat biodiesel Fuel Processor for a vehicle Fuel cell auxiliary power unit study of the feed system
Journal of Power Sources, 2005Co-Authors: Mauro Sgroi, Gianluca Bollito, Guido Saracco, Stefania SpecchiaAbstract:Abstract An integrated auxiliary power unit (APU) based on a 10 kW e integrated biodiesel Fuel Processor has been designed and is being developed. Auto-thermal reforming (ATR) and thermal cracking (TC) were considered for converting the Fuel into a hydrogen-rich gas suitable for PEM Fuel cells. The Fuel Processor includes also a gas clean-up system that will reduce the carbon monoxide in the primary Processor exit gas to below 10 ppm via a new heat-integrated CO clean-up unit, based on the assembly of catalytic heat exchange plates, so as to meet the operational requirements of a PEMFC stack. This article is devoted to the study and selection of the proper feed strategy for the primary Fuel Processor. Different pre-treatment and feed alternatives (e.g. based on nozzles or simple coils) were devised and tested for the ATR Processors, which turned out to be the preferred primary processing route. A nozzle-based strategy was finally selected along with special recommendations about the constituent materials and the operating procedures to be adopted to avoid coking and nozzle corrosion as well as to allow a wide turn down ratio.
-
conceptual design and selection of a biodiesel Fuel Processor for a vehicle Fuel cell auxiliary power unit
Journal of Power Sources, 2005Co-Authors: Stefania Specchia, F W A Tillemans, P F Van Den Oosterkamp, Guido SaraccoAbstract:Abstract Within the European project BIOFEAT (biodiesel Fuel Processor for a Fuel cell auxiliary power unit for a vehicle), a complete modular 10 kWe biodiesel Fuel Processor capable of feeding a PEMFC will be developed, built and tested to generate electricity for a vehicle auxiliary power unit (APU). Tail pipe emissions reduction, increased use of renewable Fuels, increase of hydrogen-Fuel economy and efficient supply of present and future APU for road vehicles are the main project goals. Biodiesel is the chosen feedstock because it is a completely natural and thus renewable Fuel. Three Fuel processing options were taken into account at a conceptual design level and compared for hydrogen production: (i) autothermal reformer (ATR) with high and low temperature shift (HTS/LTS) reactors; (ii) autothermal reformer (ATR) with a single medium temperature shift (MTS) reactor; (iii) thermal cracker (TC) with high and low temperature shift (HTS/LTS) reactors. Based on a number of simulations (with the AspenPlus® software), the best operating conditions were determined (steam-to-carbon and O2/C ratios, operating temperatures and pressures) for each process alternative. The selection of the preferential Fuel processing option was consequently carried out, based on a number of criteria (efficiency, complexity, compactness, safety, controllability, emissions, etc.); the ATR with both HTS and LTS reactors shows the most promising results, with a net electrical efficiency of 29% (LHV).
