Fuel processing systems mobile

An integrated fuel processing system for different fuels for mobile and small-scale stationary power units up to a range of 5 kWe was developed by the IMM [44]. A complete fuel processor for 5 kW (Figure 23.5) was set up for use of isooctane as fuel. 

The second example describes distributed, mobile and portable power-generation systems for proton-exchange membrane (PEM) fuel cells [106]. A main application is fuel processing units for fuel cell-powered automobiles it is hoped that such processing units may be achieved with a volume of less than 8 1. 

Portable fuel-cell systems are systems that produce electricity for devices with a performance ranging from several watts to 10 kilowatts. The heat produced in the process is a by-product that is normally not used. The system has, therefore, to be cooled down by fans or cooling surfaces, etc. A wide range of applications is possible for fuel cells from small electronic devices like camcorders, mobile phones, laptops, etc. to electric tools, back-up systems, or power generation on boats or caravans. 

A pilot-scale demonstration remediating harbor sediment was conducted 1 year before the SITE demonstration. Based on the pilot-scale demonstration, the processing costs for a fuU-scale, 110-ton/day unit were projected to be 230/ton (September 1992 U.S. dollars). It is assumed that the unit will be down approximately 30% of the time for maintenance and design improvements in the first year of operation. Based on this system availability, 28,105 tons can be processed in one year. This cost included estimates for variable costs, fixed costs, and deprecia-tion/insurance. Variable costs include diesel fuel for a mobile generator, hydrogen, and caustic. Fixed costs include labor diesel fuel for pumps, heaters, process equipment, and instrumentation propane, water and sewer and parts and supplies. Depreciation/insurance costs include capital cost depreciated over a 3-year period, general insurance costs, and pollution liabihty insurance. This analysis does not include costs for setup and demobilization (D128007, pp. 5.12-5.14). 

The US company Mesoscopic Devices patented a method for an adsorptive desulfurization process with integrated regeneration in mobile fuel-cell systems... 

Assuming that the residue stream can be used for another purpose in the overall system, distillative separation becomes a relevant process in mobile fuel-cell systems for rough desulfurization, provided that it considerably simplifies subsequent desulfurization with further processes. 

Due to the operating requirements of PEFC stack technology, shift reactors and a carbon monoxide removal step are required to produce reformate of sufficient quality. Similarly, the stack operating temperature and its humidity requirements require a water management system as well as radiators for heat rejection. Some developers use pressurized systems to benefit from higher reactant partial pressures on both anode and cathode. Fuel processing for PEFC APU systems is identical to that needed in residential power or propulsion applications. The additional issue for PEFC is the minimization of steam needed for the fuel processor system. Since an APU is a mobile and/or remote unit, the need for external sources of water should be minimized. The reformate stream is further diluted by additional steam, if that water is not removed prior to the fuel cell stack. 

We first consider these features common to all medium- and high-temperature fuel cells. Note that since these fuel cells use processed fuel and since use can be made of the exhaust heat, they have been mainly applied to stationary power generation systems. Although we shall see that the SOFC may find application in some mobile applications, the complexity of fuel processing usually rules out the application of high-temperature fuel cells for mobile use. 

The preferred fuel for a fuel ceU is hydrogen. While there are applications in which hydrogen can be used directly, such as in space vehicles and local transport, in the foreseeable future, for other stationary and mobile applications, the choice of fuel and its conversion into hydrogen-rich gas are essential features of practical systems. The range of fuels and their processing for use in fuel cell systems are described in Chapter 8. Chapters 9 and 10 describe the mechanical and electrical components that make up the complete fuel cell plant for both stationary and mobile applications. 

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