Instead of batch production, flow chemistry is a type of chemical reaction that is basically running in continuous flow stream. To make it simpler, pumps are moving the fluid into the tube and where the tube joins in one another, fluids get contact to each. If the fluids are reactive for instance, there is going to be a spike in reaction.
Flow chemistry is well established and known technique for use at big scale when trying to manufacture huge quantities of given material. On the other hand, the term has been coined just recently for the application on laboratory scale. Micro reactors are more often than not being used.
In most instances, continuous reactors are tube-like and at the same time, manufactured from polymers, stainless steel as well as glass because they’re known to be non reactive material. When it comes to the method of mixing, it can be either of the two, static mixers or diffusion. Continuous flow reactors are creating good control on reaction condition that includes mixing, heat transfer and time.
The residence time for reagents in reactor or the amount of time to which the reaction is being cooled or heated is being calculated from volume of reactor as well as flow rate through it. For this reason, in an effort to attain longer residence time, the reagents may be pumped slowly and /or bigger volume reactor is put into used.
The production rates on the other hand will not be constant and it varies from liters per minute to nano-liters per minute.
Few examples of the flow reactors are spinning tube reactors, spinning disk reactors or otherwise called as Colin Ramshaw, oscillatory flow reactors, multi cell flow reactors, microreactors, aspirator reactors and hex reactors. When talking about aspirator reactor, pumps are used in propelling one reagent that will then suck the reactant.
Smaller scale of the micro-flow reactors or micro reactors could be perfect for process development experiments. Although, it is possible to operate flow chemistry at bigger scale, synthetic efficiency benefits from mass transfer as well as improved thermal and also, mass transport.
Processes development is changing from serial approach to parallel. In regards to batch, the chemist will be working on it first and then, a chemical engineer will follow once they’re done. In flow chemistry, this changes to parallel approach where chemist and the chemical engineer is working interactively. In addition to that, there is a plant setup in which there is a tool designed for it. Be it non commercial or commercial setting, this set up can be useful.
It is also possible to make experiments in flow chemistry that utilizes more complex techniques similar to solid phase chemistries while solid phase reagents, scavengers or catalysts might be integrated in the solution and then, pump it on glass columns.