Steam iron process, hydrogen from

It can be seen from Figure 6 that by far, the least expensive is hydrogen by steam reforming. This results from the low plant cost for this system, which is only a fraction of that for other processes. Even though the cost of the natural-gas feed, on an energy basis, is about twice that of coal, hydrogen price is about half that from the Koppers-Totzek and Steam-Iron Processes, if by-product power from the latter is sold at 2d/kWhr. At 4c/kWhr, the price drops to less than that for partial oxidation (Figure 11). 

The future attractiveness of the coal-based process will depend upon the availability of natural gas or oil at a reasonable cost. If the coal cost rises to 1.50/106 Btu from the 1.00 level, then the cost of natural gas must rise to 3.10/106 Btu for hydrogen by the Steam-Iron Process to compete with reforming if by-product power sells at 4c/kWhr. At 2c/kWhr by-product power, natural gas cost must rise to 4.65/106 Btu for the Steam-Iron Process to be competitive. 

For the simulation studies a test reaction was chosen where the separation in a reduction and an oxidation step is necessary. The steam iron process was used in the twenties for hydrogen production from coal [12]. It includes a reduction of an iron oxide (mostly FesO )... 

The steam>iron process is another old hydrogen generation process. Although based on coal, it is actually a cycle process where hydrogen is generated from the decomposition of steam by reacting with iron oxide. The cycle, however, is not completely closed, since... 

Zinc oxide has been used to remove sitUur compounds from hydrocarbons since the 1930s, when the steam reforming process was first introduced. When a zinc oxide composition is specially prepared to have a high surface area and high degree of porosity, it can absorb more than 20 wt% sulfur in a single bed. It was the preferred choice in the early days, because the partial pressirre of hydrogen sulfide at equilibriitm imder reaction conditions, particularly in the presence of water vapour, is very small compared to that of the bog iron ore used previously to purify water gas/producer gas. 

Flow diagram of the process for hydrogen and distillate fuel production from residual oil using iron oxides and steam. 1 = Cracking reactor, 2 = distillation column, 3 = hydrogen generator, and 4 = hydrodesulfurization reactor. 

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