What Are Batch Reactors?

A batch reactor is a device that performs a chemical reaction intermittently. In chemical production, continuous reactors are usually used for large-scale production. For batch production, especially products with different specifications and high output values, batch reactors are often used. The batch reactor has the characteristics of flexible operation, variable production, low investment, and fast start-up. Therefore, it is widely used in medicine, pesticides, dyes and various fine chemical industries.

In chemical production, continuous reactors are usually used for large-scale production. For batch production, especially products with different specifications and high output values, batch reactors are often used. The batch reactor has the characteristics of flexible operation, variable production, low investment, and fast start-up. Therefore, it is widely used in medicine, pesticides, dyes and various fine chemical industries. Since the molecular weight distribution is an important quality indicator in the production of polymers, the polymerization reaction in the production of rubber and plastics is most preferably controlled by batch production. Large changes in viscosity often occur in reactants and products (such as

The batch reactor production process includes the following steps:

(1) The reactor and the catalyst are charged into the reactor, and a certain amount needs to be controlled to ensure that there is sufficient reaction space in the reaction container to prevent the reactor from overpressure.

(2) Heat to operating temperature. An interlocking device should be used to prohibit the addition of reactants before the material in the reactor reaches the reaction temperature conditions.

(3) Stop the reaction. This usually takes several hours.

The product quality of batch reactors is very unstable, and the production capacity of the equipment varies widely, which varies from person to person. In this way, the problem of automatic control of batch reactors is particularly important. No doubt, the important direction of its development is to use microcomputers to achieve optimal control.

Hydrogenation of vegetable oils such as cottonseed oil is not only the production of oil-based chemically hardened oils, but also in recent years, some domestic and foreign manufacturers have also been producing crisps and margarines, both of which are important materials for high-end food. Therefore, hydrogenation of cottonseed oil is a promising production with obvious economic and social benefits. Time-optimal control will strengthen this production capacity ^[2]

The step of the cottonseed oil intermittent hydrogenation process is to add the weighed refined cottonseed oil to the reactor. After vacuuming, stirring, and steam heating, the process will enter the reaction initiation, and then the vacuuming will be stopped. And turn on the water cooling system. After the process enters a stable reaction, and after a certain reaction time, the process will complete the required conversion rate to reach the final state. At this time, the hydrogenation can be stopped, the product can be discharged, and the subsequent processes can be filtered and bleached.

The hydrogenation result can be measured online with the refractive index meter related to the iodine value, or directly calibrated with the hydrogen consumption flowmeter. Cottonseed oil hydrogenation is a very complicated chemical reaction, because it is constrained by both chemical processes and mass transfer processes ^[1]

A multi-stage decision-making process for the transition of the batch reactor from the initial state to the final state was obtained using the dynamic programming analysis method. Time is the optimal control pressure sequence.

If the control pressure in each stage is constant, the control pressure can be obtained. That is, the pressure sequence will be the average of the slope change in each stage. With the control pressure as the given control input, a closed-loop tracking control system can be constructed.

At this time, the best performance of the closed-loop control system is that it has the fastest response speed under the action of step or slope input, that is, after a minimum of sampling cycles, the output steady-state error is zero, and the full tracking is achieved. Criteria to determine ^[3] .