Heat Exchange Mode of Pressure Vessel Reactor

According to the heat exchange conditions in the reaction process, the reactor can be divided into: isothermal reactor, an ideal reactor in which the temperature of the reactant system is equal everywhere. The reaction heat effect is small, or the heat exchange between the reaction material and the heat carrier is sufficient, or the reactor with large heat feedback in the reactor can be regarded as an isothermal reactor approximately.

An adiabatic reactor is an ideal reactor in which the reaction zone has no heat exchange with the environment. Large-scale industrial reactors without heat exchange devices in the reaction zone can be regarded as approximately adiabatic reactors when the heat exchange with the outside world is negligible. Non-isothermal non-adiabatic reactor A reactor that exchanges heat with the outside world and has heat feedback in the reactor, but does not reach isothermal conditions, such as a tubular fixed-bed reactor.

Heat exchange can be carried out in the reaction zone, such as a stirred tank for heat exchange through a jacket, or in a reaction zone, such as a multi-stage reactor for heat exchange between stages. It mainly refers to the operating temperature and operating pressure of the reactor. Temperature is a sensitive factor affecting the reaction process, and an appropriate operating temperature or temperature sequence should be selected to make the reaction process proceed under optimal conditions. For example, for reversible exothermic reactions, the temperature sequence should be high first and then low to take into account both the reaction rate and the equilibrium conversion rate.

The reactor can be operated under normal pressure, increased pressure or negative pressure (vacuum). The pressurized reactor is mainly used for the reaction process involving gas. Increasing the operating pressure is conducive to accelerating the gas phase reaction. For the gas phase reversible reaction with a reduced total mole number, the equilibrium conversion rate can be improved, such as synthetic ammonia and synthetic methanol. Increasing the operating pressure can also increase the solubility of gas in liquid, so many gas-liquid phase reaction processes and gas-liquid-solid phase reaction processes use pressurized operation to increase the reaction rate, such as the oxidation of p-xylene.