When talking about flow chemistry, this is a chemical reaction that runs in continuous flow stream rather than batch production. To be able to make things a lot simpler, the pumps move the fluid in the tube and when the tube joins in each other, the fluids then make a connection. 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. However, it was just recently when the term is coined after the application on laboratory scale. More often than not, micro-reactors are put into used.
Continuous reactors are manufactured using non reactive material similar to glass, polymers and stainless steel and typically tube-like. When it comes to the method of mixing, it can be either of the two, static mixers or diffusion. With continuous flow reactors, this is able to make good control on reaction condition that includes the heat transfer, time and mixing.
Residence time of the reagents in reactor or simply the amount of time that the reaction needed to cool or heat is observed from the reactor’s volume and at the same time, by checking the flow rate through it. So to be able to achieve a longer residence time, the reagents are slowly pumped and at times, a bigger volume reactor is what used.
The production rates are going to vary 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. Now for the aspirator reactor, there’s a pump that’s used in order to propel the reagent that is going to suck the reactant in.
Smaller scale of micro-flow reactor or the micro reactors may just be perfect on process development experiments. Even though, it is feasible to operate flow chemistry at ton scale, the synthetic efficiency benefits from the mass transfer and improved thermal as well as 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 the flow chemistry, this is changing to parallel approach where the chemist as well as the chemical engineer will interactively work on it. There is usually a plant setup in the lab to which the tool is meant for both. This set up can be seen in non commercial or commercial setting.
It is possible to run experiments in flow chemistry by using complex techniques such as solid phase chemistries while solid phase reagents, scavengers or catalysts could be used in solution and then, pump it through glass columns.