Method for separating methylcyclohexane and toluene through differential pressure thermal coupling extractive rectification

The invention provides a method for separating methylcyclohexane and toluene through differential pressure thermal coupling extractive rectification. According to the method, phenol is used as an extracting agent, and an adopted device comprises an atmospheric tower and a vacuum tower of a differential pressure thermal coupling extractive rectification tower, a phenol reclaiming tower, a compressor, a main heat exchanger, an auxiliary condenser, a heat exchanger, a condenser and a reboiler. The compressor is arranged between the vacuum tower and the atmospheric tower of the differential pressure thermal coupling extractive rectification tower; steam produced by the tower top of the vacuum tower enters the tower bottom of the atmospheric tower after being pressurized and heated by the compressor; and the latent heat of the steam from tower top of the atmospheric tower is used for heating the main heat exchanger arranged at the tower bottom of the vacuum tower so as to carry out thermal coupling between the two