Authors:Oksana Shvydkiv, Carolin Limburg, Kieran Nolan and Michael Oelgemöller
Photooxygenation of 1,5-dihydroxynaphthalene to Juglone was studied in a falling film microreactor. Moderate conversion rates of up to 31% were achieved after just 160 s of exposure to visible light. In contrast, batch reactions gave much lower conversions of up to 14% after a prolonged time period of 10 min. The difference in performance is explained by the superior light penetration in the microfilm and the large gas-liquid contact area.
Authors:Kimitada Terao, Yasuhiro Nishiyama, Hiroki Tanimoto, Tsumoru Morimoto, Michael Oelgemöller and Tsumoru Morimoto
The diastereoselective [2+2] photocycloaddition of ethylene to a chiral cyclohexenone was studied in a continuous flow microcapillary reactor. In all cases examined, the microcapillary reactor gave higher conversions and selectivity than the batch system, even after shorter irradiation times. These findings were explained by the superior temperature control, favorable light penetration, and generation of a gas–liquid slug flow with improved mass transfer in the microreactor.