Chapter 7, Problem 7.44P

Three hundred L/h of a 20 mole% ${\text{C}}_{\text{3}}{\text{H}}_{\text{8}}–\text{8}0\%$

$n-{\text{C}}_{\text{4}}{\text{H}}_{\text{1}0}$gas mixture at 0°C and 1.1 atm and 200 L/h of a 40 mole% ${\text{C}}_{\text{3}}{\text{H}}_{\text{8}}–\text{6}0\%$

   $n-{\text{C}}_{\text{4}}{\text{H}}_{\text{1}0}$mixture at 25°C and 1.1 atm are mixed and heated to 227°C at constant pressure. Enthalpies of propane and n-butane are listed below. Assume ideal-gas behavior.

T(°C)

Propane

   $\hat{H}\left(\text{J/mol}\right)$Butane

   $\hat{H}\left(\text{J/mol}\right)$ 0 0 0 25 1772 2394 227 20,685 27,442

(a) Calculate the heat requirement in kJ/h. (See Example 7.6-2.)

(b) Where in your calculations did you use the ideal-gas assumption?