Answer
$s_{gen}=0.134\ kJ/kg.K$
Work Step by Step
From the entropy balance for the steady state:
$\dot{S}_{in}-\dot{S}_{out}+\dot{S}_{gen}=0$
$\dot{S}_{gen}=\dot{m}(s_2-s_1)$
$s_{gen}=s_2-s_1$
$s_{gen} = c_p\ln\left(\dfrac{T_2}{T_1}\right)-R\ln\left(\dfrac{P_2}{P_1}\right)$
Given $c_p=1.047\ kJ/kg.K,\ R=0.2968\ kJ/kg.K,\ T_2=563K,\ T_1=298K$
$P_2=600\ kPa,\ P_1=100\ kPa$:
$s_{gen}=0.134\ kJ/kg.K$
