HYDROFORMYLATION PROCESS IN THE PRESENCE OF A SULFUR-CONTAINING ADDITIVE

A hydroformylation process comprising reacting a compound having at least one olefinic carbon-to-carbon bond with hydrogen and carbon monoxide in the presence of a cobalt catalyst, the hydroformylation process being carried out in one or more reactors, at least one of which comprises a gas cap region and a liquid-containing region while in use, characterized in that a sulphur-containing additive is present on the inside walls of the gas cap region of the at least one-reactor which comprises a gas cap region and a liquid-containing region. The sulphur-containing additive suppresses the formation of methane during the hydroformylation process.