For effective flowsheet-level calculation of a complex chemical plant, the use of suitable partitioning and tearing techniques is inevitable. The partitioning and tearing techniques based on the reachability matrix and the decomposition algorithm were applied to model and simulate a sulfolane extraction plant. Basic concepts were first exploited towards a general representation for the modeling and simulation of the sulfolane extraction process. Six process units, which consist of the sulfolane extraction plant, were modeled first and partitioning and tearing techniques were employed to model and simulate the whole extraction plant. The Inside-Out method and the sequential-modular approach were used in the modeling and simulation. Results of simulations showed good agreement with plant operation data.