Process for recovering heat from a hydrocarbon separation

A process for separating hydrocarbons and recovering heat comprising:

• separating a stream comprising in a first separation zone configured to separate the stream into an overhead stream and a C3+ bottoms stream;
• passing the C3+ bottoms stream to a second separation zone configured to separate the C3+ bottoms stream and provide a propylene overhead stream and a bottoms stream, the bottom stream including propane;
• passing the bottoms stream of the second separation zone to a third separation zone;
• passing the propylene overhead stream to a first compression zone configured to compress the propylene overhead stream and provide a compressed propylene overhead stream;
• passing a first portion of the compressed propylene overhead stream to a heat exchange zone associated with the second separation zone configured to remove heat from the first portion of the compressed propylene overhead stream;
• passing a second portion of the compressed propylene overhead stream to a separation vessel configured to allow the second portion of the compressed propylene overhead stream to be cooled and separate into a vapor propylene stream and a liquid propylene stream;
• reducing a pressure of at least a portion of the liquid propylene stream to provide a reduced pressure stream, the reduced pressure stream comprising a mixture of liquid and vapor;
• passing the reduced pressure stream to a second heat exchange zone associated with the first separation zone and configured to vaporize liquid in the reduced pressure stream and provide a vaporized propylene stream, wherein the second heat exchange zone also receives a portion of the overhead stream from the first separation zone;
• passing the vaporized propylene stream to a second compression zone configured to compress the vaporized propylene stream and provide a re-compressed propylene stream;
• and,
• passing the re-compressed propylene stream to the separation vessel.

A system for separating hydrocarbons and recovering heat comprising:

• a first separation zone comprising a fractionation column configured to receive and separate a stream into an overhead stream and a C3+ bottoms stream;
• a second separation zone comprising a fractionation column configured to receive and separate the C3+ bottoms stream and provide a propylene overhead stream and a bottoms stream, the bottom stream comprising propane;
• a first compression zone configured to compress the propylene overhead stream and provide a compressed propylene overhead stream;
• a heat exchange zone associated with the second separation zone and configured to remove heat from the first portion of the compressed propylene overhead stream;
• a separation vessel configured to receive and separate a second portion of the compressed propylene overhead stream into a vapor propylene stream and a liquid propylene stream;
• a valve configured to receive a portion of the liquid propylene stream and provide a reduced pressure stream;
• a second heat exchange zone, the second heat exchange zone associated with the first separation zone and configured to heat the reduced pressure portion and provide a vaporized propylene stream;
• a second compression zone configured to compress the reduced pressure stream and the vapor propylene stream and provide a re-compressed propylene stream;
• and,
• one or more lines configured to pass the re-compressed propylene stream to the separation vessel.