Application of a bottom divided wall column (bdwc) with and without vapor recompression (vrc) to separate aromatic rich streams from the pyrolysis gasoline hydrogenation reactor

A process for converting hydrocarbons to olefins and aromatics, comprising:

• steam cracking a hydrocarbon feedstock to produce a cracked effluent;
• separating the cracked effluent to recover one or more light hydrocarbon fractions, a pyrolysis gasoline fraction, and one or more heavy hydrocarbon fractions;
• hydrotreating the pyrolysis gasoline fraction in one or more reactors to recover a pyrolysis gasoline reactor effluent;
• separating hydrogen and hydrogen sulfide from the pyrolysis gasoline reactor effluent to recover an offgas stream and a hydrotreated pyrolysis gasoline;
• feeding the hydrotreated pyrolysis gasoline to a divided wall distillation column, the divided wall distillation column including:
• a bottom dividing wall segregating a lower portion of the divided wall distillation column into a first side and a second side, wherein the hydrotreated pyrolysis gasoline is fed to the first side;
• and
• an upper separation zone receiving vapor from both of the first side and second side and providing liquid to both of the first side and second side;
• separating the hydrotreated pyrolysis gasoline in the divided wall distillation column to recover an overheads fraction comprising C6 hydrocarbons;
• separating the hydrotreated pyrolysis gasoline in the first side to recover a first bottoms fraction comprising C9 and heavier hydrocarbons;
• separating, in the second side, liquid received from the upper separation zone to recover a second bottoms fraction comprising C7 and C8 hydrocarbons.

A system comprising:

• a divided wall distillation column configured to receive a hydrotreated pyrolysis gasoline, the divided wall distillation column including:
• a bottom dividing wall segregating a lower portion of the divided wall distillation column into a first side and a second side, wherein the hydrotreated pyrolysis gasoline is provided to the first side;
• and
• an upper separation zone configured for receiving vapor from both of the first side and second side and providing liquid to both of the first side and second side;
• wherein the divided wall distillation column is configured to:
• separate the hydrotreated pyrolysis gasoline in the divided wall distillation column to recover an overheads fraction comprising C6 hydrocarbons;
• separate the hydrotreated pyrolysis gasoline in the first side to recover a first bottoms fraction comprising C9 and heavier hydrocarbons;
• separate, in the second side, liquid received from the upper separation zone to recover a second bottoms fraction comprising C7-C8 hydrocarbons;
• a flow splitter or valving configured to divide the overheads fraction into a first portion and a second portion;
• a compressor for compressing the first portion to produce a compressed first portion;
• a first reboiler for indirectly heating a portion or an entirety of the second bottoms fraction with the compressed first portion, producing a partially cooled first portion and for providing reboiling duty to the second side;
• one or more coolers, interchangers and condensers for cooling and condensing the partially cooled first portion and the second portion to produce a condensed liquid;
• a reflux drum for receiving the condensed liquid;
• a reflux flow line for feeding a portion of the condensed liquid as reflux to a top tray of the upper separation zone of the divided wall distillation column;
• and
• an overhead product line for recovering a remaining portion of the condensed liquid as a C6 product fraction;
• a first heat exchanger for indirectly heating the hydrotreated pyrolysis gasoline with the second bottoms fraction;
• a second heat exchanger for indirectly heating the hydrotreated pyrolysis gasoline with the partially cooled first portion, producing a cooled first portion;
• and
• a compressor suction stream heater for indirectly heating the first portion of the overheads fraction with the cooled first portion.