CATOFIN dehydrogenation is a continuous process, with cyclic reactor operation. During the hydrocarbon processing step, fresh feed and recycle feed (from C3 splitter bottoms) are vaporized by exchange with various process streams and then raised to reaction temperature in the charge heater. The reactor effluent is routed through a high pressure steam generator, feed-effluent exchanger, and trim cooler to the compressor.
The compressor discharge is cooled, dried and routed to the low temperature recovery section to reject light ends. The low temperature section off gas, which is a hydrogen-rich gas, is partly sent to a Pressure Swing Adsorption Unit (PSA) to purify the hydrogen. Remaining off gas is used partly in the reactor and the balance is used as fuel gas. Recovered liquids from the low temperature recovery section, along with the effluent flash drum liquid, are fed to distillation facilities for product recovery.
Ancillary equipment is required for the reheat/ regeneration steps that are necessary to prepare the off-line reactors for their next reaction phase. The entire reactor sequence is computer controlled and requires no operator input for the cyclic operation.