Acoustic measurements of critical points for four-component mixtures in hydroformylation reactions in carbon dioxide

A simple acoustic technique has been used to study the vapour–liquid critical points of the reaction mixtures of hydroformylation in carbon dioxide. The systems CO2+CO+H2+propene and CO2+CO+H2+hex-1-ene have been investigated. These two quaternary systems were measured by the pseudo-binary approach (i.e. the ratio of alkene, CO and H2 being held constant). The effects of the solutes (alkene, CO and H2) on the critical points in the CO2-rich fluids are discussed.