Managing solids in microreactors for the upstream continuous processing of fine chemicals

The management of solid compounds is a major challenge facing the upstream, continuous processing of pharmaceuticals and fine chemicals. Many reactions relevant to fine chemical production either react with or form insoluble materials, which become problematic in continuous flow microreactors. The deposition, growth, or bridging of compounds can limit fluid flow from the micro- to the mesoscale, and thereby render continuous reactors inoperable. A comprehensive approach for managing solids consists of solids identification, the development of the root failure mechanism(s), and the application of active and passive techniques for the prevention and remediation. This review examines the basic principles of microreactor design for reactions that involve solids, toward the goal of performing the continuous flow processing of fine chemicals.