Determine the desired steam flow-rate in kg/hr for a steam reformer and note your assumptions/reasons for selecting this flow-rate. (d) Determine the desired air flow-rate in kg/hr for a partial oxidation reformer design. Must add only enough air to produce 0.5 moles O2 per mole of CH4

(c)

(d)

Explanation:

Hello,

In this case, the problem is:

Assume that you are designing a reformer reactor that is part of a fuel cell fuel processor system that will use natural gas (primarily methane, CH₄) as the primary fuel for a 100 kWe fuel cell.

Thus, the undergoing chemical reactions are:

Hence, assuming a 60% overall efficiency for the fuel cell and considering that methane's heat of combustion is 50000 kJ/kg, the flow rate methane turns out:

Now, one could compute the desired steam flow-rate by assuming a steam to carbon ratio of 2.5 to avoid coking:

Finally, to compute the desired air flow-rate, it is necessary to specify a O₂ to CH₄ ratio of 0.5 (based on the first reaction):

Best regards.