Question: Consider the reactor shown in Fig. This reactor is similar to a furnace in that the energy required for the reaction is provided by the combustion of a fuel with air (to simplify the diagram, the temperature control is not completely shown). Methane and steam are reacted to produce hydrogen by the reaction

CH₂ + 2H₂O → CO₂ + 4H₂

The reaction occurs ‘in tubes inside the furnace. The tubes are filled with a catalyst needed for the reaction. It is important that the reactant mixture always be steam-rich to avoid coking the catalyst. That is, if enough carbon deposits over the catalyst, it poisons the catalyst. This situation can be avoided by ensuring that the entering mixture is always rich in steam. However, too much steam is also costly in that it requires more energy (fuel and air) consumption. The engineering department has estimated that the optimum ratio R, (methane to steam) must be maintained.  will be maintained and that during increases and decreases in production rate, the reactant mixture will be steam-rich. Please note that there is a signal that sets the hydrocarbon flow set point required.