When talking about flow chemistry, this is a chemical reaction that runs in continuous flow stream rather than batch production. For you to understand things a lot easier, the pumps move the fluid in the tube and by the time that the tubes are connected, the fluid forms into one. Expect to have a spike in reaction in the event that the fluids are reactive.
Flow chemistry is well established and known technique for use at big scale when trying to manufacture huge quantities of given material. The term has been just recently coined for application on laboratory use. Well most of the time, what is used is micro reactors.
Continuous reactors are also manufactured by using non reactive material such as glass, stainless steel and polymer and also, mostly tube-like. The mixing methods may include diffusion as well as static mixers. The continuous flow reactors create good control on the reaction condition which include time, mixing and heat transfer.
Residence time for the reagent in the reactor or amount of time wherein the reaction is cooled or heated is checked from the volume of reactor and the flow rate through it. For this, the reagents are pumped slowly and/or it is using bigger volume reactor to be able to attain longer residence time.
When it comes to production rates, this can be liters per minute to nano-liters per minute.
The spinning tube reactors, Colin Ramshaw, oscillatory flow reactors, multi cell flow reactors, aspirator reactors, microreactors and hex reactors are only some of the flow reactors being used. In regards to aspirator reactor, a pump is used to propel one reagent that sucks in the reactant.
When it comes to process development experiments, using smaller scale of micro flow reactors or micro reactors are just perfect. 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.
Process development changes from using serial approach to parallel. Now when talking about batch, the chemist is going to work first and then, they’ll be followed by a chemical engineer. 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.