I think it's obvious to the authors that a batch reactor approach is/would be sufficient for the laboratory, but not for industrial applications to large-scale polymer needs. From the Supporting Information:
In the current photo irradiation process, liquid reactant was gradually converted to solid precipitate. At the late stage of reaction process, a small amount of liquid reactant/intermediates were trapped in the solid precipitate. It is therefore inherently difficult to reach more than 90% conversion. Nevertheless, the problem can be overcome by designing a dynamic flow reactor allowing regular removal of solid precipitated products from the bottom of the reactor when a large scale production of solid adipic acid is concerned.In my favorite formulation of the moment, "can" is doing a lot of work in that last sentence there. (Presumably, you'd need a ozone flow unit (and those exist), combined with a photoirradiation flow unit -- who knows, it could be done.)
I presume the economics would not work out for adipic acid, but would probably work out for higher-value monomers. Who knows? Either way, definitely a very interesting method -- congrats to the Hwang group.