A continuous process to prepare an aromatic dicarboxylic acid, comprising: oxidizing a di-alkyl substituted aromatic compound with compressed air in an acetic acid reaction medium in a primary bubble column reactor in the presence of a catalyst to obtain a three phase reaction medium; removing a portion of the three phase reaction medium containing catalyst from the primary bubble column reactor to a post-oxidation bubble column unit supplied with compressed air to obtain a post oxidized reaction medium; transferring the post oxidized reaction medium to a de-gassing unit and separating the post oxidation reaction medium to an overhead gas and an underflow slurry; collecting an overhead gas from each of the primary oxidation reactor and the post-oxidation reactor with the overhead gas from the de-gassing unit and conducting the combined overhead gases to a water removal column; transferring the underflow slurry from the de-gassing unit to a digestion unit wherein the temperature of the underflow slurry is increased to a temperature to at least partially dissolve precipitated solids and effect further oxidation of exposed intermediate oxidation products with air and catalyst present in the underflow slurry without addition of air to the digestion unit, to obtain a final oxidation slurry; removing overhead gases from the digestion unit to the water removal column; crystallizing the final oxidation slurry to obtain a filtration-ready slurry of the aromatic dicarboxylic acid; filtering the filtration-ready slurry on a rotary pressure filter to obtain a mother liquor filtrate and a filtercake; wherein the overhead gases sent to the water removal column are separated in the water removal column to an off gas comprising steam removed from the top of the column and an underflow liquid comprising acetic acid, at least a portion of the energy of the off gas comprising steam is collected and employed to drive an air compressor to supply the compressed air to the bubble column primary reactor and the post-oxidation bubble column unit, and the water content of the continuous oxidation is controlled by removal of water condensed from the water removal column off-gas. oxidizing a di-alkyl substituted aromatic compound with compressed air in an acetic acid reaction medium in a primary bubble column reactor in the presence of a catalyst to obtain a three phase reaction medium; removing a portion of the three phase reaction medium containing catalyst from the primary bubble column reactor to a post-oxidation bubble column unit supplied with compressed air to obtain a post oxidized reaction medium; transferring the post oxidized reaction medium to a de-gassing unit and separating the post oxidation reaction medium to an overhead gas and an underflow slurry; collecting an overhead gas from each of the primary oxidation reactor and the post-oxidation reactor with the overhead gas from the de-gassing unit and conducting the combined overhead gases to a water removal column; transferring the underflow slurry from the de-gassing unit to a digestion unit wherein the temperature of the underflow slurry is increased to a temperature to at least partially dissolve precipitated solids and effect further oxidation of exposed intermediate oxidation products with air and catalyst present in the underflow slurry without addition of air to the digestion unit, to obtain a final oxidation slurry; removing overhead gases from the digestion unit to the water removal column; crystallizing the final oxidation slurry to obtain a filtration-ready slurry of the aromatic dicarboxylic acid; filtering the filtration-ready slurry on a rotary pressure filter to obtain a mother liquor filtrate and a filtercake; wherein the overhead gases sent to the water removal column are separated in the water removal column to an off gas comprising steam removed from the top of the column and an underflow liquid comprising acetic acid, at least a portion of the energy of the off gas comprising steam is collected and employed to drive an air compressor to supply the compressed air to the bubble column primary reactor and the post-oxidation bubble column unit, and the water content of the continuous oxidation is controlled by removal of water condensed from the water removal column off-gas.