Hydrogen production large-scale

In Germany, large-scale production of synthetic fuels from coal began in 1910 and necessitated the conversion of coal to carbon monoxide and hydrogen. 

Methods for the large-scale production of hydrogen must be evaluated in the context of environmental impact and cost. Synthesis gas generation is the principal area requiring environmental controls common to all syngas-based processes. The nature of the controls depends on the feedstock and method of processing. 

The catalyst activity, given as average turnover frequency (TOF mol product per mol catalyst per reaction time units h-1), affects the production capacity. For hydrogenations, TOFs should be >200h 1 for small-scale products, and >10000 IT1 for large-scale products. Due to lower catalyst costs and often higher added values, lower TON and TOF values are acceptable for enantioselective oxidation and C-C bond-forming reactions. 

The purest hydrogen (>99.95% pure) is made by electrolysis of water. However, this process requires a large amount of energy—286 kj per mole of H2 produced— and thus is not economical for large-scale production. 

Marketability of fuel-cell-powered vehicles will depend both on their initial cost and the ready availability of hydrogen in convenient filling stations. Prototype cars are on the road in a few cities, and large-scale production may have the potential to eventually make such vehicles affordable and competitive, but the obstacles are significant. 

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