Process for Separating Hydrogen from an Olefin Hydrocarbon Effluent Vapor Stream

A process for providing refrigeration to warm streams within a heat exchanger comprising:

• a. separating a pressurized and cooled mixed refrigerant composition via at least one discharge vapor/liquid separator to provide a mixed refrigerant vapor product stream and a mixed refrigerant liquid product stream;
• b. cooling the mixed refrigerant vapor product stream via a heat exchanger to provide a cooled and liquified mixed refrigerant vapor product stream;
• c. cooling the mixed refrigerant liquid product stream via the heat exchanger to provide a subcooled mixed refrigerant liquid product stream;
• d. lowering the pressure of the cooled and liquified mixed refrigerant vapor product stream via a first control valve;
• e, lowing the pressure of the subcooled mixed refrigerant liquid product stream via a second control valve;
• f. vaporizing the pressure-reduced, cooled, and liquefied mixed refrigerant vapor product stream via the heat exchanger, wherein the vaporization provides cooling to warm streams within the heat exchanger;
• g. combining the pressure-reduced, subcooled mixed refrigerant liquid product stream to the pressure-reduced, cooled, and liquefied mixed refrigerant product stream within the heat exchanger to provide a combined stream;
• h. compressing the combined stream in at least one compressor with at least one stage of compression to provide a compressed mixed refrigerant stream;
• and
• i. cooling the compressed mixed refrigerant stream in at least one discharge cooler to provide the pressurized and cooled mixed refrigerant composition.