high raw material efficiencies, e.g.. high conversion of olefinic unsaturated compounds. 

This invention relates in part to a hydrofonnylation pro› cess which comprises reacting one or more olefinic unsat› urated compounds with carbon monoxide and hydrogen in the presence of a metal-organopolyphosphite ligand com› plex catalyst to produce a reaction product fluid comprising one or more aldehydes. wherein said hydroformylation process is conducted at a free organopolyphosphite ligand concentration sufficient to prevent and/or lessen hydrolytic degradation of the organopolyphosphite ligand and deacti› vation of the metal-organopolyphosphite ligand complex catalyst. 

This invention also relates in part to a hydroformylation process which comprises reacting one or more olefinic unsaturated compounds with carbon monoxide and hydro› gen in the presence of $_{a }$metal-organopolyphosphite ligand complex catalyst to produce a reaction product fluid com› prising one or more aldehydes, wherein said hydroformyla› tion process is conducted (a) at a free organopolyphosphite ligand concentration sufficient to prevent and/or lessen hydrolytic degradation of the organopolyphosphite ligand and deactivation of $_{the }$metal-organopolyphosphite ligand complex catalyst and (b) at a reaction zone and/or separator zone residence time sufficient to prevent and/or lessen hydrolytic degradation of the organopolyphosphite ligand and deactivation of $_{the }$metal-organopolyphosphite ligand complex catalyst. 

This invention further relates in part to an improved hydroformylation process for producing one or more alde- hydes which comprises (i) reacting in at least one reaction zone one or more olefinic unsaturated compounds with carbon monoxide and hydrogen in the presence of a metal› organopolyphosphite ligand complex catalyst to produce a reaction product fluid comprising one or more aldehydes and (ii) separating in at least one separation zone or in said at least one reaction zone the one or more aldehydes from said reaction product fluid. the improvement comprising prevent› ing and/or lessening hydrolytic degradation of the organ› opolyphosphite ligand and deactivation of the metal- organopolyphosphite ligand complex catalyst by conducting said hydroformylation process (a) at a free organopolyphos› phite ligand concentration sufficient to prevent and/or lessen hydrolytic degradation of the organopolyphosphite ligand and deactivation of $_{the }$metal-organopolyphosphite ligand complex catalyst, and (b) at a reaction zone and/or separator zone residence time sufficient to prevent and/or lessen hydrolytic degradation of the organopolyphosphite ligand and deactivation of $_{the }$metal-organopolyphosphite ligand complex catalyst; and by treating in at least one acid removal zone at least a portion of said reaction product fluid derived from said hydroforrnylation process and which also contains phosphorus acidic compounds formed during said process with an acid removal substance sufficient to remove at least some amount of the phosphorus acidic compounds from said reaction product fluid. 

This invention yet further relates in part to an improved hydroformylation process for producing one or more alde› hydes which comprises (i) reacting in at least one reaction zone one or more olefinic unsaturated compounds with carbon monoxide and hydrogen in the presence of a metal› organopolyphosphite ligand complex catalyst to produce a reaction product fluid comprising one or more aldehydes and (ii) separating in at least one separation zone or in said at least one reaction zone the one or more aldehydes from said reaction product fluid, the improvement comprising prevent› ing and/or lessening hydrolytic degradation of the organ- 

opolyphosphite ligand and deactivation of the metal› organopolyphosphite ligand complex catalyst by conducting said hydroforrnylation process (a) at a free organopolyphos› phite ligand concentration sufficient to prevent and/or lessen hydrolytic degradation of the organopolyphosphite ligand and deactivation of $_{the }$metal-organopolyphosphite ligand complex catalyst, and (b) at a reaction zone and/or separator zone residence time sufficient to prevent and/or lessen hydrolytic degradation of the organopolyphosphite ligand and deactivation of $_{the }$metal-organopolyphosphite ligand complex catalyst; and by removing phosphorus acidic com› pounds from said reaction product fluid derived from said hydroforrnylation process by (a) withdrawing from said at least one reaction zone or said at least one separation zone at least a portion of a reaction product fluid derived from said hydroformylation process and which also contains phosphorus acidic compounds formed during said hydro› forrnylation process, (b) treating in at least one acid removal zone at least a portion of the withdrawn reaction product fluid derived from said hydroformylation process and which also contains phosphorus acidic compounds formed during said hydroformylation process with an acid removal sub› stance sufficient to remove at least some amount of the phosphorus acidic compounds from said reaction product fluid, and (c) returning the treated reaction product fluid to said at least one reaction zone or said at least one separation zone. 

## BRIEF DESCRIPTION OF THE DRAWING 

FIG. 1 is a graphical representation of free ligand con› centration (grams/liter) versus average ligand usage (grams/ liter/day) based on the experimental data set out in Table A herein. 

The hydroformylation processes of this invention may be asymmetric or non-asymmetric, the preferred processes being non-asymmetric, and may be conducted in any con› tinuous or semi-continuous fashion and may involve any catalyst liquid and/or gas recycle operation desired. Thus it should be clear that the particular hydroformylation process for producing such aldehydes from an olefinic unsaturated compound, as well as the reaction conditions and ingredients of the hydroformylation process are not critical features of this invention. As used herein, the term "hydroformylation" is contemplated to include, but not limited to, all permissible asymmetric and non-asymmetric hydroformylation pro› cesses which involve converting one or more substituted or unsubstituted olefinic compounds or a reaction mixture comprising one or more substituted or unsubstituted olefinic compounds to one or more substituted or unsubstituted aldehydes or a reaction mixture comprising one or more substituted or unsubstituted aldehydes. As used herein, the term "reaction product fluid" is contemplated to include, but not limited to, a reaction mixture containing an amount of any one or more of the following: (a) a metal› organopolyphosphite ligand complex catalyst. (b) free orga› nopolyphosphite ligand, (c) one or more phosphorus acidic compounds formed in the reaction, (d) aldehyde product formed in the reaction, (e) unreacted reactants, and (f) an organic solubilizing agent for said metal› organopolyphosphite ligand complex catalyst and said free organopolyphosphite ligand. The reaction product fluid encompasses, but is not limited to, (a) the reaction medium in the reaction zone, (b) the reaction medium stream on its way to the separation zone, (c) the reaction medium in the 

## DEfAILED DESCRIPITON 

