A reaction occurs in a well-mixed fluidized bed reactor maintained at 450°C. Heat is removed by Dowtherm A™ circulating through a coil in the fluidized bed. In the design or base case, the Dowtherm enters and exits the reactor at 320°C and 390°C, respectively. In the base case, the heat transfer resistance on the reactor side is two times that on the Dowtherm side. It may be assumed that for the fluidized bed, the heat transfer coefficient on the fluidized side is essentially constant and independent of the throughput.

The Dowtherm is cooled in an external exchanger that produces steam at 900 psig (T_sat = 279°C). The Dowtherm pump limits the maximum increase in Dowtherm flowrate, so the pump limits the heat removal rate based on its pump and system curves.

For the current situation, the maximum increase in Dowtherm flowrate through the reactor and boiler is estimated to be 34%. By how much can the process be scaled-up? You may assume that the limiting heat transfer coefficient in the steam boiler is Dowtherm that flows through the tube side of the exchanger.