Processes to improve catalytic metal accountability in hydroformylation processes
Embodiments of the present invention are directed to processes to improve rhodium accountability in continuous liquid recycle hydroformylation processes. In some embodiments, a process comprises contacting in a reaction zone reactants comprising C7-C20 olefins, hydrogen, and carbon monoxide in the presence of a catalyst comprising rhodium and an organomonophosphite ligand to form a reaction fluid, wherein the feed rate of olefins to the reaction zone is greater than 100 kilograms/hour; providing the reaction fluid to a strip gas vaporizer to produce a product stream and a vaporizer tails stream; measuring the C7-C20 olefin content in the vaporizer tails stream; and adding a C7-C20 olefins stream comprising at least 50 weight percent C7-C20 olefins to the vaporizer tails stream to maintain the C7-C20 content in vaporizer tails stream above 2 percent by weight.
1 . A process to improve rhodium accountability in a continuous liquid recycle hydroformylation process, the process comprising:
contacting in a reaction zone reactants comprising C7-C20 olefins, hydrogen, and carbon monoxide in the presence of a catalyst comprising rhodium and an organomonophosphite ligand to form a reaction fluid, wherein the feed rate of olefins to the reaction zone is greater than 100 kilograms/hour;
providing the reaction fluid to a strip gas vaporizer to produce a product stream and a vaporizer tails stream;
measuring the C7-C20 olefin content in the vaporizer tails stream; and
adding a C7-C20 olefins stream comprising at least 50 weight percent C7-C20 olefins to the vaporizer tails stream to maintain the C7-C20 content in vaporizer tails stream above 2 percent by weight.
2 . The process of claim 1 , wherein the stream comprising at least 50 weight percent C7-C20 olefins is added to the vaporizer tails stream by one or more of:
(a) adding the C7-C20 olefins stream to the vaporizer catchpot bottom liquid layer; or
(b) adding C7-C20 olefins stream to the vaporizer tail cooler; or
(c) adding C7-C20 olefins stream immediately before the vaporizer bottoms pump; or
(d) adding C7-C20 olefins stream immediately after the vaporizer bottoms pump.
3 . The process of claim 1 , further comprising removing olefins from the product stream and returning a portion of the removed olefins as part of the C7-C20
olefins stream added to the vaporizer tails stream.
4 . The process of claim 3 , wherein a majority of the C7-C20 olefins in the C7-C20 olefins stream added to the vaporizer tails stream are removed olefins from the product stream.
5 . The process of claim 1 , wherein a majority of the olefins contacted in the reaction zone are C8 olefins.
6 . The process of claim 5 , wherein the product stream comprises isononyl aldehyde.
7 . The process of claim 1 , wherein the solubility of the catalyst and catalyst components is increased by the addition of the C7-C20 olefins stream to the vaporizer tails stream.