Process for producing n-hexane by using reformate raffinate oil

The invention relates to a process for producing n-hexane by using reformate raffinate oil. After the raffinate oil is pre-treated in a C5 decarbonization tower, low-boiling mixed C5 light components are distilled from the top of the C5 decarbonization tower; mixed C6 and C7 components at the bottom of the C75 decarbonization tower enter into a C7 decarbonization tower; after the mixed C6 and C7 components are treated in the C7 decarbonization tower, mixed C7 components are discharged from the bottom of the C7 decarbonization tower; unseparated mixed components enter into a C6 decarbonization tower from the top of the tower; after treatment in the C6 decarbonization tower, distillates at the top of the C6 decarbonization tower are mixed C6 components, a mixture at the bottom of the C6 decarbonization tower enters into an extractive distillation tower; a fraction at the top of the extractive distillation tower is high pure n-hexane, a mixture at the bottom of the extractive distillation tower enters into a solvent recovery tower; a distillate at the top of the solvent recovery tower is methylcyclopentane and a distillate at the bottom of the solvent recovery tower is an extraction agent which can be reused. The process solves the problems of comprehensive utilization of the reformate raffinate oil of an oil refinery, and increases deep processing level of oil products. A concentration of n-hexane can reach over 95%; and simultaneously, the mixed C5, mixed C6 and mixed C7 components are recycled.