Energy Balance in Steady-State PFR: ConcepTest and Example Problem

Try to answer this ConcepTest and solve this example problem before using this module. Studies show that trying to answer the questions before studying material improves learning and retention. By the end of this module, you should be able to answer these on your own. Answers will be given later in this module.

Example Problem 1

A second-order endothermic reaction (ΔH = 25,000 J/mol) takes place in a steady-state, jacketed plug flow reactor.

A → B + C      k = 1016e(-15,000/T) cm3/(mol min)     T is in kelvin

The reactor feed contains A at 250°C and a concentration of 2.5×10-3 mol/cm3The tubular reactor diameter is 8.0 cm, and the heat transfer coefficient through the walls is 30 J/(cm2 K min).  The fluid in the jacket surrounding the reactor is at 300°C. Is the temperature of the reactor contents immediately downstream from the inlet higher or lower than the feed temperature?