batchreactor

Batch reactor

A batch reactor is a closed vessel in which all reactants are charged at the start, the reaction proceeds for a defined residence time, and the reactor is emptied after the products are formed. It operates as a well-mixed system, with temperature controlled by a jacket or internal coil and agitation to ensure uniform composition and heat transfer. In some cases an inert blanket or venting is used to manage pressure and prevent unwanted side reactions. Because there is no continuous feed or withdrawal, the reaction trajectory depends on the batch time and the initial charge.

Kinetics and design: Reaction rates are governed by the chosen rate law, with concentrations changing with time according to the differential equations of the batch system. Temperature and heat release must be managed; the heat generated by exothermic steps is removed by cooling duty, affecting the maximum usable temperature and batch size. Material compatibility and cleaning-in-place are important for multi-batch operation.

Advantages include simplicity, flexibility, and ease of handling hazardous reactions; good control of reaction time, product quality, and heat removal in small volumes. Disadvantages include lower space-time yield, downtime between batches, and scaling challenges due to heat and mixing limitations.

Applications: used in pharmaceutical synthesis, specialty chemicals, polymerization, catalysts, and lab-scale research. Variants include semi-batch or fed-batch processes, where one or more components are added during the reaction to control conversion or heat evolution.

Compared with continuous reactors such as CSTRs or PFRs, batch reactors are discrete and time-dependent, offering versatility at small to medium scales but often less suited to high-volume, continuous production.