Processes and apparatuses for producing a C8 aromatic isomer product are provided. The apparatus comprises an isomerization unit to provide an isomerized stream. An isomerate stripper column is in communication with the isomerization unit to provide an isomerate stripper overhead stream comprising C6− hydrocarbons in an isomerate overhead line and an isomerate stripper bottoms stream in an isomerate bottoms line. A dividing wall naphthene splitter column is in communication with the isomerate bottoms line to provide an overhead naphthene splitter stream comprising the C8 naphthenes and C7 aromatic hydrocarbons in a naphthene splitter overhead line and a naphthene splitter sidedraw stream comprising C8 aromatic isomers in a naphthene splitter sidedraw line. An extractive distillation column is in communication with the naphthene splitter overhead line to provide a recycle feedstream comprising the C8 naphthenes in a recycle line and an extract stream comprising the C7 aromatic hydrocarbons in an extract line.