638 Fuel Cells
ii. The efciencies and impacts of processing are also of importance.
Today’s crude oil–based fuels exhibit an extremely high energetic
efciency of more than 90%. In contrast, steam or combined reform-
ing of natural gas for hydrogen and methanol production, respec-
tively, has comparatively lower efciencies. Thus, it is important to
distinguish between the production of gasoline in average reneries
and marginal plants.
iii. The upstream and downstream processes involving different require-
ments for transportation or distribution are the third important fac-
tor for the assessment of the fuel supply. The possible use of joint
products can reduce environmental impacts if there is a market for
the by-product.
In the case of ...