The consumption of washing oil per ton of benzene recovery was reduced from 70 kg to 30 kg by improving the process of benzol stripping and optimizing operation parameters.Crude benzol recovery rate was also increased.With negative pressure collection technology,the gas vent from top of each tank in the benzol unit can be transferred to the gas system before the primary cooler.As a result,VOCs emission can be discharged as per environmental regulation,environment protection level was upgraded to a new high.