The stream leaving the chlorine absorber must be heated from 25°C to 50°C before it enters the chlorination reactor. The heat capacity of PVC is 1.2 kJ/(kg∙°C) and the heat capacity of dissolved chlorine (in either PVC or water) is 0.96 kJ/(kg∙°C). At what rate (kJ/h) must heat be transferred to the slurry in the reactor preheater?