US Patent 11312674 Process for making a feed of normal butanol, iso-butanol and 2-alkyl alkanol

A process for the production of normal-butanol, iso-butanol and 2-alkyl alkanol is disclosed. The process comprises: hydrogenating a feed comprising normal butyraldehyde, iso-butyraldehyde and 2-alkyl alkenal to form a crude product stream comprising normal-butanol, iso-butanol, 2-alkyl alkanol, unreacted normal butyraldehyde, unreacted iso-butyraldehyde and one or more of unreacted 2-alkyl alkenal, 2-alkyl alkanal or 2-alkyl alkenol; separating the crude product stream to produce: a mixed butanol stream having higher concentrations of normal butanol, iso-butanol, unreacted normal butyraldehyde and unreacted iso-butyraldehyde than the crude product stream; and a crude 2-alkyl alkanol stream having higher concentrations of 2-alkyl alkanol and the one or more of unreacted 2-alkyl alkenal, 2-alkyl alkanal or 2-alkyl alkenol than the crude product stream; separating the mixed butanol stream to produce: a refined normal butanol stream having a higher concentration of normal butanol than the mixed butanol stream; and a crude iso-butanol stream having a higher concentration of iso-butanol than the mixed butanol stream; feeding the crude iso-butanol stream to a first polishing hydrogenation reactor wherein at least some of the unreacted iso-butyraldehyde is converted to iso-butanol to produce a polished iso-butanol stream; separating the polished iso-butanol stream to produce: a refined iso-butanol stream having a higher concentration of iso-butanol than the polished iso-butanol stream; and a light waste stream; separating the crude 2-alkyl alkanol stream to produce: an intermediate 2-alkyl alkanol stream having higher concentrations of 2-alkyl alkanol and the one or more of unreacted 2-alkyl alkenal, 2-alkyl alkanal or 2-alkyl alkenol than the crude 2-alkyl alkanol stream; and a heavy waste stream; feeding the intermediate 2-alkyl alkanol stream to a second polishing hydrogenation reactor wherein at least some of the one or more of unreacted 2-alkyl alkenal, 2-alkyl alkanal or 2-alkyl alkenol is converted to 2-alkyl alkanol to produce a polished 2-alkyl alkanol stream having a higher concentration of 2-alkyl alkanol than the intermediate 2-alkyl alkanol stream; separating the polished 2-alkyl alkanol stream to produce: a refined 2-alkyl alkanol stream having a higher concentration of 2-alkyl alkanol than the polished 2-alkyl alkanol stream; and an intermediate waste stream.