Distillation column heat pump with compressor inlet superheater

摘要

Hydrocarbon distillation columns with heat pumps and methods of operating them are described. The overhead stream is compressed to increase temperature so that it can be used both to heat the reboiler and to superheat the overhead stream before it enters the heat pump compressor.

主权项

1. A process for hydrocarbon distillation comprising:
providing a hydrocarbon feed stream to a fractionation zone at a first position; fractionating the hydrocarbon feed stream into an overhead stream and a bottoms stream; heating a first portion of the overhead stream to a temperature above a dew point temperature of the overhead stream; compressing the heated first overhead stream portion; removing a portion of a stream from the fractionation zone at a second position below the first position; heating the removed stream portion by indirectly contacting the removed stream portion with the compressed first overhead stream portion; returning the heated removed stream portion to the fractionation zone at a third position above the second position and below the first position; reducing the pressure of the compressed first overhead stream portion to form a reduced pressure overhead stream; returning a portion of the reduced pressure overhead stream to the top of the fractionation zone;wherein heating the first overhead stream portion comprises indirectly contacting the first overhead stream portion with the compressed first overhead stream portion after indirectly contacting the removed stream portion with the compressed first overhead stream portion and before reducing the pressure of the compressed first overhead stream portion.