Study Compares Batch And Flow Photochemistry

Researchers studying a photochemical reaction for the first time must figure out whether a batch reactor or a flow reactor will better serve their needs. The answer is “it’s complicated,” according to a new study (Chem. Eur. J. 2014, DOI: 10.1002/chem.201404347). Kevin I. Booker-Milburn of England’s University of Bristol teamed with Novartis and GlaxoSmithKline chemists to compare batch and flow photoreactors. They ran 12 different reactions, each with its own optimized conditions of time, flow rate, light source, and reactant concentration. They used batch reactors made of quartz or Pyrex and flow reactors consisting of flexible, UV-transparent tubing wrapped in one or three layers around a light source. The batch and flow reactions had similar yields and productivity for the same time scales. Michael Oelgemöller, who specializes in flow photochemistry at Australia’s James Cook University, cautions that the study looked at just one type of flow reactor and involved reactions known to run smoothly in batch reactors. Flow chemistry can save on materials costs, among other advantages, Oelgemöller adds. He urges industry chemists to continue pursuing flow photochemistry technology and making improvements to it.