. A catalytic reactor is used to produce formaldehyde from methanol in the reaction

CH3OH HCHO +H2

A single-pass conversion of 60.0% is achieved in the reactor. The methanol in the reactor product is separated from the formaldehyde and hydrogen in a multiple-unit process. The production rate of formaldehyde is 900.0 kg/h.

(a) Calculate the required feed rate of methanol to the process (kmol/h) if there is no recycle.

(b) Suppose the unreacted methanol is recovered and recycled to the reactor and the single-pass conversion remains 60%. Without doing any calculations, prove that you have enough information to determine the required fresh feed rate of methanol (kmol/h) and the rates (kmol/h) at which methanol enters and leaves the reactor. Then perform the calculations.

(c) The single-pass conversion in the reactor, Xsp, affects the costs of the reactor (Cr) and the separation process and recycle line (Cs). What effect would you expect an increased Xsp would have on each of these costs for a xed formaldehyde production rate? (Hint: To get a 100% single-pass conversion you would need an innitely large reactor, and lowering the single-pass conversion leads to a need to process greater amounts of uid through both process units and the recycle line.) What would you expect a plot of (Cr + Cs) versus Xsp to look like? What does the design specication Xsp = 60% probably represent?