Chemical Reactor Definition

Candela Rocío Barbisan
Chemical engineer

Equipment in which a certain chemical reaction occurs, therefore, within it, the correct contact between the reagents must be ensured to ensure the degree of mixture.

Features that are based on your design

In addition to the degree of mixing provided by the agitation system present inside the reactor, there is another important factor to take into account, the contact time between the reagents, which is also the basis of his design to ensure a certain conversion of reactants to one or more products. On the other hand, in the case of a reaction that requires a catalyst, contact between the reactants and the catalyst phase must be ensured.

Likewise, each reactor is designed for a given condition and operation, continuous or batch type and for certain pressure ranges, temperature and composition of the fluid.

For all these reasons, it is understood that when designing the rector, the thermodynamic and kinetic aspects of the reaction that is desired to be carried out inside it are taken into account.

Variety of chemical reactors in the industry

According to the reaction to be carried out and with the previously mentioned aspects, there is a wide variety of chemical reactors today, which are the heart of any chemical process. Next, we will see some of them and their main characteristics:

According to the mode of operation, we classify them into: continuous, discontinuous or batch, semicontinuous or semibatch reactor. A continuous reactor whose inlet flow and discharge is constant, that is, while the reaction occurs the system is fed continuously as is the withdrawal of the product. On the other hand, batch reactors are fed only once at the beginning and a certain interval of time is waited for the reaction to proceed. considerably, withdrawing the product, by-products and surplus at the end of that predetermined time interval, after this operation it is charged again to repeat the cycle.

In the case of an operation that combines both types, we speak of a semibatch reactor where initially a first load, a time interval is expected and part of the product is withdrawn, also being able to feed intermittently with more reagent and withdrawing product from time to time.

Depending on the type of flow, the reactors are classified into tubular or stirred tanks. In the case of the tubular reactor, as its name indicates, the reactor is a coil through which the reactants circulate and as it progresses through the tubular, the reaction progresses. In many cases the tubular is submerged in a bath that provides the necessary temperature conditions. On the other hand, if the reactor is of the stirred tank type, it is sought to be a container that has a agitation inside to ensure a degree of mixing and a certain residence time within its inside.

If the reaction requires its passage through a bed, there are type reactors fluidized bed, fixed bed or moving charge, as its name implies, the bed may be in slight motion good static The first one is usually used in the case of solid-gas type reactions, passing the current gaseous by the solid bed and suspending particles, ensuring the necessary contact area between the phases. On the other hand, if the bed is packed and fixed, a fixed bed reactor is used, they are generally vertical reactors, in where the fluid is passed through several tubulars that contain the bed inside, generally particles of catalyst. In the moving bed reactor, they generally work in countercurrent, feeding the solid from the top and the fluid from the bottom.

In addition, we can mention the type reactors trickle bed, which have achieved a significant boom in recent years. In this case, the reactor is fed with a gaseous current and a liquid one, passing them through a packaging machine catalytic particles, taking advantage of the dripping of the liquid, being able to work in different conditions of operation.

Last but not least, the fermenters They are reactors that are used for the crop of fungus, from the matter formed after a considerable time, this product is extracted and can be used in different industries such as pharmaceuticals, cosmetics, brewing, among others. It is worth clarifying, a fermenter is not the same as a bioreactor, in this case, the reaction is catalyzed by a organism and has defined the operating conditions to promote the growth of the product being cultivating.