Ruthenium-catalyzed hydroformylation: from laboratory to continuous miniplant scale

Hydroformylation of alkenes for the production of aldehydes is one of the most important homogeneously catalyzed reactions on an industrial scale. Mostly, these processes are based on expensive rhodium as the catalyst metal. In this contribution, we present for the first time the successful application of ruthenium as a cheaper alternative metal in a continuously operated miniplant. In the reaction of 1-octene, ex situ extraction of the oxo-products is conducted using the nonpolar solvent iso-octane, while the catalyst is retained in a polar DMF phase. After optimizing the reaction conditions on a batch scale, the recycling of the ruthenium catalyst was realized over a period of 90 h in a fully automated miniplant setup.