Desulfurization of Natural Gas-Absorbers and Adsorbers

Our process to produce H2 from natural gas is idealized We assumed that our natural gas source is 100% methane. Typically, natural gas has only 85 to 95% methane the balance is chiefly ethane, propane, and propene. Natural gas also contains small concentrations ( 1% total) of He, CO2, and N2. None of these constituents will affect the process diagram above and so we will ignore them. However, natural gas also contains H2S. Up to 3 parts per million (ppm), or 0.0003%, H2S is allowed. Although 3 ppm may seem like an inconsequential impurity level, it is a problem. A concentration of H2S above 0.1 ppm will deactivate the catalyst in the first reactor. We need to remove H2S from the natural gas. 

Let s assume further that we are going to build our fuel-cell generator at the natural gas source, the well head. Instead of piping natural gas to consumers, we will convert it to electricity on site and pump electricity to consumers. But at the well head, the level of H2S is even higher - 100 ppm. Our task is  

PROBLEM Reduce the H2S level to less than 0.1 ppm in the natural gas.  

we first consider gas/liquid separation. We prepare a table of boiling points. 

Engineering. .. is the art of doing that well with one dollar, which any bungler can do with two after a fashion. 

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