Process for recovery of phosphorus ligand from vaporized aldehyde

In a liquid recycle rhodium catalyzed hydroformylation process for producing aldehydes, wherein an olefinic compound, carbon monoxide and hydrogen are reacted in the presence of a solubilized rhodium-phosphorus complex catalyst, free phosphorus ligand and higher boiling aldehyde condensation by-products to produce an aldehyde product and wherein said aldehyde is separated and recovered from a liquid reaction aldehyde product solution containing aldehyde product, solubilized rhodium-phosphorus complex catalyst, free phosphorus ligand and higher boiling aldehyde condensation by-products that has been removed from the hydroformylation reactor, by vaporizing the aldehyde product contained in said solution to obtain a vaporized aldehyde product stream consisting essentially of aldehyde product, vaporized phosphorus ligand and vaporized higher boiling aldehyde condensation by-products which is disengaged in a separator from the remaining non-volatilized catalyst containing liquid reaction product solution that is recovered from the bottom of the separator and recycled back to the reaction system, the improvement which comprises (a) selectively separating the phosphorus ligand contained in said vaporized aldehyde product stream by thoroughly contacting said stream with a spray of dispersed liquid having a lower boiling point than said higher boiling aldehyde condensation by-products so as to condense the vaporized phosphorus ligand and vaporized higher boiling aldehyde condensation by-products contained in said volatilized aldehyde product stream, and (b) recovering the condensed phosphorus ligand and condensed higher boiling aldehyde condensation by-products so obtained from said volatilized aldehyde product stream, said dispersed liquid being employed in the form of droplets and in an amount such that the percent of phosphorus ligand so separated and recovered is at least 1.2 times higher than the percent of higher boiling aldehyde condensation by-products also so separated and recovered and wherein the amount ratio of dispersed liquid employed per flow rate of volatilized aldehyde product stream is about 5 to 60 pounds per hour of dispersed liquid per 1000 pounds per hour of volatilized aldehyde product stream.