Autothermal fuel processors

Design, build and demonstrate a fully integrated, 50-kilowatt electric (kWe) catalytic autothermal fuel processor system. The fuel processor will produce a hydrogen-rich gas for direct use in proton exchange membrane (PEM) fuel cell systems for vehicle applications. 

A fully integrated autothermal fuel processor based on a bi-fimctional ATR catalyst has been designed, fabricated and checked out. The unit continues to show progress towards the FreedomCAR targets and will be tested in the summer of2002. 

Measure the emissions from a partial oxidation/autothermal fuel processor for a proton exchange membrane (PEM) fuel cell system under both cold-start and normal operating conditions. 

The heat balance of an autothermal reformer is dictated by its S/C ratio, which affects the amount of air feed required for a net heat balance. Increasing the S/C ratio thus increases the O/C ratio, as shown in Table 5.10. From the overall chemical reaction of an autothermal fuel processor (assuming that carbon monoxide is completely converted into carbon dioxide) it follows that less moles of hydrogen are produced per mole of fuel at higher O/C ratios. This because less fuel is converted... 

Table 5.11 Operating conditions for autothermal fuel processors running on different fuels as calculated by Semelsberger and Borup.

Figure 5.50 Effect of the H/C ratio of different fuels on the net water recovery of an autothermal fuel processor working at a S/C ratio of 1.5 the water recovery is normalised by the heating value of the fuel the O/C ratio is adjusted such that thermo neutral conditions result for the overall fuel processor [435].

The development of an even bigger methanol fuel processor/fuel cell system with a power output of 75 kW was reported by Yan et al. [584]. The autothermal fuel processor, which is shown in Figure 9.12, reUed on catalytic carbon monoxide dean-up... 

Calculate composition (in vol. % of dry gas) of a reformate gas obtained by reforming methane CH4 in an autothermal fuel processor with gas shift... 

There are three major gas reformate requirements imposed by the various fuel cells that need addressing. These are sulfur tolerance, carbon monoxide tolerance, and carbon deposition. The activity of catalysts for steam reforming and autothermal reforming can also be affected by sulfur poisoning and coke formation. These requirements are applicable to most fuels used in fuel cell power units of present interest. There are other fuel constituents that can prove detrimental to various fuel cells. However, these appear in specific fuels and are considered beyond the scope of this general review. Examples of these are halides, hydrogen chloride, and ammonia. Finally, fuel cell power unit size is a characteristic that impacts fuel processor selection. 

Autothermal reforming provides a fuel processor compromise that operates at a lower 0/C and lower temperature than the POX is smaller, quicker starting, and quicker responding than the SR and results in good H2 concentration and high efficiency. A catalytic POX must be used to reduce the reaction temperature to a value compatible with the SR temperature. Once started, surplus heat from other parts of the unit can be sent to the ATR to increase its efficiency. 

There have been fuel processor configurations where a non-catalytic POX is placed in series with a steam reformer. Without catalyst, the POX reaction has to be at a higher temperature than the steam reformer reaction. These reactions have to take place in separate compartments with heat exchange and a wall between them (13). This configuration is not considered within the definition of autothermal reforming. 

An experimental study by Lee et al. [72] reported the development and testing of a natural gas fuel processor, which incorporates a catalytic autothermal reformer, a sulfur trap and a WGS reactor. The fuel processor was successfully run over 2300 h of continuous operation. The ATR reactor gave over 40% H2 (dry basis) in the ATR reformate and 96-99.9% methane conversion over the entire test duration. 

A compact design for a gasoline fuel processor for auxiliary power unit (APU) applications, including an autothermal reformer followed by WGS and selective oxidation stages, was reported by Severin et al. [83]. The overall fuel processor efficiency was about 77% with a start-up time of 30 min. 

A stand-alone IkW integrated fuel processor for gasoline, incorporating an autothermal reformer followed by high- and low-temperature WGS reactors, was reported by Qi et al. [85]. The start-up of the ATR reformer lasted less than 5 min and stabilized in around 50 min for the whole system. 

Integrated Autothermal Methanol Fuel Processor (Ballard)... 

Schuessler et al. [85] of XCELLSiS (later BALLARD) presented an integrated methanol fuel processor system based on autothermal reforming, which coupled fuel/water evaporation with exothermic preferential oxidation (PrOx) of carbon monoxide. The reactor technology was based, in contrast to most other approaches, on a sintering technique. 

Schwank, )., Tadd, A., Gould, B., Autothermal reforming of simulated gasoline in compact fuel processor,... 

Recupero, V., Pino, L., Vita, A., Cipiti, F., Cordaro, M., and Lagana, M. Development of a LPG fuel processor for PEFC systems Laboratory scale evaluation of autothermal reforming and preferential oxidation subunits. International Journal of Hydrogen Energy, 2005, 30 (9), 963. 

Autothermal reformers and CPO are being developed by a number of groups, mostly for fuel processors of gasoline, diesel, and JP-8 fuels and for natural gas-fueled proton exchange membrane fuel cell (PEMFC) cogeneration systems. A few examples are the following ... 

Figure 7.12. MEMs SCT fuel processor. ATR, Autothermal Reformer WGSR, Water Gas Shift Reactor. See color insert.

Utilize integrated STAR (Substrate based Transportation application Autothermal Reformer) fuel processor, MPR (Modular Pressurized Reformer - a disintegrated fuel processor), high temperature material test facility, and microreactors to perform endurance testing that will identify and address component and fuel processor degradation mechanisms. 

Improve catalytic activity and reduce the cost of autothermal reforming (ATR) catalyst to decrease the size of the fuel processor and reduce start-up time. 

Lee SHD, Applegate DV, Ahmed S, Calderone SG, Harvey TL (2005) Hydrogen from natural gas. Part I autothermal reforming in an integrated fuel processor. Int J Hydrogen Energy 30 829-842... 

Kolb G, Baier T, Schilrer J, Tiemann D, Ziogas A, Ehwald H, Alphonse P (2008) A micro-structured 5 kW complete fuel processor for iso-octane as hydrogen supply system for mobile auxiliary power units. Part 1 development of autothermal reforming catalyst and reactor. Chem Eng J 137 653-663... 

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