Process for the recovery of pure aromatics from hydrocarbon fractions containing aromatics

A process for the dealkylation of a hydrocarbon mixture rich in C7 to C9 aromatics, comprising:

• submitting the aromatics-rich starting hydrocarbon mixture to an extractive distillation in which the aromatics-containing hydrocarbon mixture is distilled by means of a suitable extracting solvent and freed from it, obtaining a product flow significantly depleted from aromatic hydrocarbons and free of solvent as well as an aromatics concentrate significantly enriched in aromatic hydrocarbons and free of solvent;
• passing the solvent-free aromatics concentrate to a reactor for hydrodealkylation after the extractive distillation, where it is reacted with hydrogen, giving a dealkylated aromatics stream as main product and a paraffinic hydrocarbon stream and a methane stream as by-products;
• and
• passing the aromatic hydrocarbon stream to a treatment unit;
• wherein
• the extractive distillation and recovery of the extracting solvent take place in one column.

An apparatus for the dealkylation of a hydrocarbon mixture rich in aromatics, comprising:

• a rectifying column for the extractive distillation with an extracting solvent;
• a stripping column for the removal of the extracting solvent;
• a reactor for the hydrogenation of the aromatics concentrate obtained from the stripping column;
• and
• a treatment unit for the purification of the aromatics concentrate obtained;
• wherein
• the rectifying column, the stripping column, the hydrogenation reactor and the purification unit are arranged such that an extractive distillation of aromatic hydrocarbons from a hydrocarbonaceous mixture, a separation of extracting solvent from the aromatic product flow, a hydrodealkylation of aromatics for obtaining a dealkylated aromatic product and a purification of the aromatic product obtained are carried out one after the other in direction of the process flow;
• and
• the apparatus comprises a column which facilitates an extractive distillation and the recovery of the extracting solvent in one column.