The reformer product gas leaves the reformer at 855°C.

(a) Using the flow rate of the product gas determined in Problem 13.5, calculate the rate (kJ/h) at which heat must be transferred from the combustion gases to the gases flowing through the inside of the reformer tubes.

(b) What is the required flow rate of natural gas (kmol/h and SCMM) to the reformer burners? Assume that the natural gas is burned to completion in the reformer firebox and that the combustion gases leave the firebox at 960°C.

(c) The thermal effciency of the firebox may be defined as the percentage of the lower heating value of the fuel transferred to the reformer gases. Estimate the lower heating value of methane and, assuming the combustion gases leave the firebox at 960°C, the corresponding thermal efficiency of the firebox.