Fuel cost, tradeoffs between

Cost optimization basically depends on the tradeoffs between the cost of energy (fuel) and capital investment, as seen in Figure 5.1. Fines for pollution and incentives for environment-friendly technologies may reduce the cost associated with exergy loss. 

Whether produced from fossil or non-fossil sources, the widespread use of hydrogen will require a new and extensive infrastructure to produce, distribute, store and dispense it as a vehicular fuel or for stationary applications, such as electric generation. Depending on the source from which hydrogen is produced and the form in which it is delivered, many alternative infrastructures can be envisioned. Tradeoffs in scale economies between process and distribution technologies, and such issues as operating cost, safety, and materials can also favour alternative forms of infrastructure. 

While substantial quantities of only a few experimental syn-fuels have been generated, those which are available have demonstrated the degradation problems that were predicted from work with petroleum. The high heteroatom and unsaturate content of syncrudes derived from shale and coal will necessitate closer attention to processing parameters required to produce a commercially viable product. This paper presents basic and applied data which should aid in the tradeoff decisions between further costly processing and product stability. Because this is a progress report on continuing work, many of the conclusions are preliminary in nature. 

Selection of the fuel-element diameter is the next step in the design procedure. The tradeoff is between fabrication costs, which decrease with increasing diameter, and inventory costs, which increase with increasing diameter. Following selection of the fuel-element diameter, the surface heat flux is calculable, and the design procedure iterates considering the flux assumption made in the thermal analysis. 

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