Fuel cell hardware recycling

Abstract Whereas much attention has been paid to the environmental aspects of the life cycle of fuel cell fuel production, emphasis is placed on fuel cell hardware and materials recovery, including component reuse, remanufacturing, materials recycling and energy recovery for fuel cell maintenance and retirement processes. Fuel cell hardware recycling is described and issues related to the recycling infrastructure and the compatibihty of fuel cell hardware and materials are discussed. The role of materials selection and recovery in the fuel cell hfe cycle is described. Future trends for fuel cells centered on voluntary and mandatory recovery and the movement of life cycle considerations from computational research laboratories to design complete the discussion. 

Fuel cell hardware recycling promises to be an important environmental aspect of mass-produced systems. In recovery, materials are collected and separated before being reused, remanufactured, recycled or used for energy recovery, as follows ... 

Assumes 80% of hydrogen is reacted in the fuel cell, and the fuel cell is 60% efficient. Assumes 1 kg device hardware, 14 day mission, water recycle, anode gas recycle, and parasitic power = 3 W. Assumes 3 kg device hardware, 14 day mission, water recycle, anode gas recycle, and parasitic power = 5 W. Assumes 5 kg device hardware, 14 day mission, water recycle, anode gas recycle, and parasitic power = 10 W. 

In this chapter, three applications of this model are demonstrated. The comparison of different reforming concepts reveals the advantages of direct internal reforming (DIR) in the anode channel of the fuel cell. Moreover, with the help of the proposed model, the benefit of fuel cell cascades can be demonstrated and they can be compared to single cells. Results indicate that a considerable power increase can be expected, but the additional hardware required might offset any benefit in the case of smaller systems. The third application demonstrates that anode gas recycle can be simulated with this model, but it also reveals its limitations, as temperature effects are not considered. 

The reforming process requires heat, which is delivered by a burner that can either be fed with fuel from the tank or with recycled anode waste gas from the fuel cell [19]. Supplying the reformer with heat solely from the combustion of recycled anode waste gas is the basis for an efficient fuel cell reformer process. The anode stoichiometry (Aa,min) required to satisfy the heat demand is determined by the specific enthalpy of the reforming reaction (AH°) for each fuel (see Table 23.2). The efficiency of heat transfer fi-om the burner gas and the reformer is not included in this theoretical value because it depends on the individual hardware design. 

Reuse of components tends to be preferred among hardware recycling options. Reuse refers to the direct use of components and subassemblies back into fuel cells without additional processing. The Society of Automotive Engineers (2003) notes that reuse depends on separability, the demand for reusable components in repair or replacement, component durability, the cost of new components and the collection and distribution infrastructure. However, reuse is also hampered by design changes as new features are incorporated into fuel... 

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