Question

what happens if the water flowrate "coolant" in a reactor is suddenly decreased on increased?

can this lead to thermal runaway reaction?

Answer 1

The Coolant (Cooling Fluid) is mainly used in the exothermic reaction to remove the heat generated during reaction and hence to maintain the temperature of reaction media according to process design. When the flow of cooling media sudden increased or decreased, the temperature of the reaction disturb which disturb the chemical reaction (Rate of reaction and even yield of the reaction).

i). When the flow of cooling media increased suddenly, it lower the temperature of the reaction media (Exothermic reaction). If the process design temperature of reaction is normal such as 30 C, then the disturbance may not cause significant effect to the reaction.

ii). When the flow of cooling media Decrease suddenly and continue there for some time, then the temperature of reaction media keep on increasing continuously and causes the continues heat built up into reactor. In this case when the reaction involves any high volatile reactant constituent then its cause the vaporization of reactant before reaction into product resulting the pressure build up in the reactor. sometimes when reactants are having low flammable or self ignition it cause fire or explosion in the reactor. During exothermic reaction when heat is not removed properly and if heat build is continuous in reaction media, after certain limit the forward reaction of final product to initial reagents. In many cases, the initiation of side reactions which results high boiling impurities.