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. More often than not, micro-reactors are put into used.
Continuous reactors are also manufactured by using non reactive material such as glass, stainless steel and polymer and also, mostly tube-like. 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.
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.
When it comes to production rates, this can be liters per minute to nano-liters per minute.
Some examples of the flow reactors include the spinning tube reactors, spinning disk reactors, oscillatory flow reactors, multi cell flow reactors, aspirator reactors and hex reactors. When talking about aspirator reactor, pumps are used in propelling one reagent that will then suck the reactant.
When it comes to process development experiments, using smaller scale of micro flow reactors or micro reactors are just perfect. 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.
From serious to parallel approach, process development is going to change. In regards to batch, the chemist will be working on it first and then, a chemical engineer will follow once they’re done. Now for flow chemistry, this changes to parallel approach to which both the chemical engineer and the chemist are working side by side. Typically, there’s plant setup in lab wherein there’s a tool intended for both. This particular set up may be used either for non commercial or commercial setting.
It’s feasible as well to run experiments in flow chemistry using more complicated techniques like solid phase chemistries while solid phase reagents, scavengers or catalysts may be used in the solution and be pumped through glass columns.