Enabling easy access to flow chemistry: stainless steel reactors with a heating and cooling device printed using a standard FDM 3D printer

Abstract

Continuous production of chemicals under flow conditions is one of the most modern synthesis methods in the industry. The industry takes full advantage by using primarily stainless steel reactors. These industrial reactors are very expensive, and the more cost-effective alternatives, such as coiled tubes, often lack sufficient mixing capacities and are not suitable for laboratory work due to their large volume. Herein we present 3D-printed stainless steel (316L) flow reactors, which could be printed using a standard desktop FDM printer, making this technology easily accessible for every research facility. Thermal conductivity is one of the major advantages in choosing stainless steel as the reactor material. Therefore, we developed an application that allows the reactor to be heated or cooled directly, making the device very compact and easy to handle. The reactor can be heated directly up to 200 °C with a heating element, and the cooling can be accomplished using a Peltier element reaching temperatures under −20 °C. To investigate the functionality of the microreactors, we performed a Diels–Alder reaction with methyl vinyl ketone and a cannabinoid derivative at high temperatures and a subsequent reduction of the carbonyl group with DIBAL-H at low temperatures. In addition to its high thermal conductivity, stainless steel also features favorable chemical and mechanical resistance, highlighting the need for a convenient and simple way to manufacture such reactors. With this technology, we aim to provide a solution that enhances usability and amplifies the impact of flow chemistry in research.