SPLITTER WITH MULTI-STAGE HEAT PUMP COMPRESSOR AND INTER-REBOILER

摘要

A splitter system is disclosed that produces a product stream from a mixed stream of two materials. A multi-stage heat pump compressor is used in combination with a bottoms reboiler and an intermediate reboiler resulting in reduced utility consumption. The intermediate reboiler enables use of a lower temperature heat source relative to the bottoms reboiler heat source. The first stage of the multi-stage heat pump compressor delivers pressurized overhead vapor to the intermediate reboiler and the second stage provides pressurized overhead vapor to the bottoms reboiler. The disclosed design and method lessens the heat pump compressor power consumption and trim condenser duty for a propylene/propane splitter system by over 20%. A third stage of compression upstream of the overhead trim condenser may be used for purposes of making the column pressure and temperatures independent of the trim condenser temperature.