Logistic fuels

Early expectations of very low emissions and relatively high efficiencies have been met in power plants with each type of fuel cell. Fuel flexibility has been demonstrated using natural gas, propane, landfill gas, anaerobic digester gas, military logistic fuels, and coal gas, greatly expanding market opportunities. Transportation markets worldwide have shown remarkable interest in fuel cells nearly every major vehicle manufacturer in the U.S., Europe, and the Far East is supporting development. 

IFC conducted testing of a 100 kW mobile electric power plant (MEP) with the logistic fuels of JP-8 and DF-2. An auto-thermal reformer that achieved 98% conversion was used to convert the logistic fuel to a methane rich fuel. 

SOFCo, a limited partnership of Babcock and Wilcox (a McDermott International Company) and Ceramatec (an Elkem company), has tested a planar SOFC unit for the MEP program that will operate on logistic fuels. Honeywell tested their MEP unit on logistic fuel. 

All demonstrations showed that fuel cell units can be operated with military logistic fuels (18). 

M. M. Piwetz, J.S. Larsen, T.S. Christensen, "Hydrodesulfurization and Pre-reforming of Logistic Fuels for Use in Fuel Cell Applications," Fuel Cell Seminar Program and Abstracts, Courtesy Associates, Inc., November 1996. 

Logistic fuels, such as jet and diesel fuels, are readily available, but a compact and effective way to remove sulfur from these fuels is needed for portable hydrogen production. Consequently, for most portable applications, it is likely that sulfur-free fuels, such as methanol, will be used. An additional advantage of methanol is that it is easier to activate at low temperatures than other hydrocarbons. Therefore, a portable hydrogen production unit based on methanol steam reforming would be simpler and less costly than other alternatives. Methanol can also be considered an energy carrier as an alternative to liquefied natural gas... 

P. Muzzel, Reforming and Synthetic JP-8 Programs , 4th DoD Logistics Fuel Reforming Conference, Philadelphia, USA, October 22-23, 2003. 

The formation of coke is not a problem for UMR since any coke that is formed is burnt off during the air regeneration step. This allows the use of UMR with diesel/logistics fuel and possibly with biomass pyrolysis liquids, though the latter has not yet been demonstrated. 

Electrocatalysis of the oxidation of logistic fuels (hydrocarbons, reformer gas, methanol, coal)... 

Fig. 10. Adiabatic prereforming of logistic fuel . Temperature profiles. Topsoe RKNGR catalyst.

As was described in Section 2.3, Sammels et al [2.310] have recently reported the use of solid oxide membranes (brownmillerite) for gasifying coal. In the same study they have reported the use of such membranes in a catalytic MR for the autothermal reforming of logistic fuels (JP-8 and DF-2), in order to deliver a gaseous feedstock compatible for subsequent use in a SOFC. This is an important application, which makes it feasible for directly using such fuels in a SOFC. 

Annual Department of Defense Logistic Fuel Reforming Workshop, Panama City, Florida, August 26 - 29, 2002. 

Surdoval, W. A. and Berry, D. A, "Solid State Energy Conversion Alliance", 3 Annual Department of Defense Logistic Fuel Reforming Workshop, Panama City, Florida, August 26 - 29, 2002. 

Small SOFC systems in the 10-500 W power range operating on hydrocarbon fuels have been considered and developed for portable applications. Examples of portable apphcations are battery charging, remote power, and low-level auxiliary power [50, 51]. Portable SOFC systems are particularly suitable for tactical military applications (e.g., soldier power and unmanned vehicle power) due to its potential for operation on logistics fuels such as JP-8 [52]. 

D., Nickens, and A. (2006) U.S. Navy sorbent development for liquid-phase removal of sulfur from logistics fuels for fuel cell applications. Presented at Fuel Cell Seminar, San Antonio, TX. 

Durai-Swamy, K. (2006) Membrane desulfurization of logistic fuels for fuel cell auxiliary power units. Presented... 

Much knowledge on the effect of poisons has been generated in connection to reformer-based PEMFC systems. Both for transport as well as for stationary applications, the presence of CO, CO2, NH3 has to be taken into account besides N2 and H2O [100]. For reformer-based systems that are operated dynamically, that is, including many cold starts and load variations, CO concentrations exceed the 10 ppm level frequently [104]. The effect of CO is studied most extensively. For unalloyed platinum electrodes, CO concentrations as low as 10 ppm lead to a performance loss of 100 mV [105] at 70°C. When reformer-based systems are fueled with logistic fuels, such as diesel and kerosene, other contaminants than CO and CO2 are present in the reformate. Especially aromatics and unsaturated hydrocarbons can poison the fuel cell anode fast and irreversibly, even in concentrations so low that they are hardly detectable with state-of-the-art analytics. 

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