Chapter 5, Problem 5.63P

A stream of liquid n-pentane flows at a rate of 50.4 L/mm into a heating chamber, where it evaporates into a stream of air 15% in excess of the amount needed to bum the pentane completely. The temperature and gauge pressure of the entering air are 336 K and 208.6 kPa. The pentane-laden heated gas flows into a combustion furnace in which a fraction of the pentane is burned. The product gas, which contains all of the unreacted pentane and no CO. goes to a condenser in which both the water formed in the furnace and the unreacted pentane are liquefied. The uncondensed gas leaves the condenser at 275 K and 1 atm absolute. The liquid condensate is separated into its components, and the flow rate of the pentane is measured and found to be 3.175 kg/mm.

(a) Calculate the fractional conversion of pentane achieved in the furnace and the volumetric flow rates (L/min) of the feed air, the gas leaving the condenser, and the liquid condensate before its components are separated.

(b) Sketch the apparatus that could have been used to separate the pentane and water in the condensate. Hint: Remember that pentane is a hydrocarbon and recall what is said about oil (hydrocarbons) and water.