Process for separating hydrogen from an olefin hydrocarbon effluent vapor stream
One or more specific embodiments disclosed herein includes a method for separating hydrogen from an olefin hydrocarbon rich compressed effluent vapor stream, employing an integrated heat exchanger, multiple gas-liquid separators, external refrigeration systems, and a rectifier attached to a liquid product drum.
1. A process for providing refrigeration comprising:
a. providing an integrated main heat exchanger, wherein the integrated main heat exchanger comprises a first pass, a second pass, and a third pass as well as a first cold pass, a second cold pass, a third cold pass, a fourth cold pass, and a fifth cold pass, and further wherein the integrated main heat exchanger comprises a first warm pass, a second warm pass, and a third warm pass;
b. separating a mixed refrigerant composition via at least one discharge vapor/liquid separator to provide a pressurized and cooled vapor refrigerant stream and a pressurized and cooled liquid refrigerant stream, wherein the pressurized and cooled vapor refrigerant stream comprises a pressure between 2,500 kPa·G and 4,000 kPa·G, and further wherein the pressurized and cooled liquid refrigerant stream comprises a pressure between 2,500 kPa·G and 4,000 kPa·G;
c. sending the pressurized and cooled vapor refrigerant stream into the top of the integrated main heat exchanger, wherein the pressurized and cooled vapor refrigerant stream travels down the first pass, wherein the pressurized and cooled vapor refrigerant stream becomes a cooled liquid stream by passing near the first cold pass, the second cold pass, the third cold pass, the fourth cold pass, the fifth cold pass, and the second pass, wherein the cooled liquid stream comprises a temperature between −100° C. and −120° C.;
d. sending the pressurized and cooled liquid refrigerant stream into the top of the integrated main heat exchanger, wherein the pressurized and cooled liquid refrigerant stream travels down the third pass, wherein the pressurized and cooled liquid refrigerant stream becomes a subcooled liquid stream;
e. lowering the pressure of the cooled liquid stream via a first pressure control valve to provide a pressure-reduced, temperature-decreased vapor/liquid mixed stream, wherein the pressure-reduced, temperature-decreased vapor/liquid mixed stream comprises a pressure between 150 kPa·G and 450 kPa·G and a temperature between −105° C. and −130° C., and further wherein the pressure-reduced, temperature-decreased vapor/liquid mixed stream proceeds directly to the integrated main heat exchanger, wherein the pressure-reduced, temperature-decreased vapor/liquid mixed stream enters the bottom of the integrated main heat exchanger and travels upwards through the second pass to provide refrigeration to the first warm pass, the second warm pass, the third warm pass, and the first pass;
f. lowering the pressure of the subcooled liquid stream via a second pressure control valve to provide a pressure-reduced, temperature-decreased liquid stream, wherein the pressure-reduced, temperature-decreased liquid stream proceeds directly to the integrated main heat exchanger;
g. combining the pressure-reduced, temperature-decreased liquid stream with the pressure-reduced, temperature-decreased vapor/liquid mixed stream within the second pass of the integrated main heat exchanger to provide a warm, vaporized stream, wherein the warm, vaporized stream comprises a pressure between 50 kPa·G and 350 kPa·G;
h. compressing the warm, vaporized stream in at least one mixed refrigerant compressor with at least one stage of compression to provide a compressed stream; and
i. cooling the compressed stream in at least one discharge cooler to provide the mixed refrigerant composition.
2. The process of claim 1 , wherein the refrigeration process is a closed-loop process.
3. The process of claim 1 , wherein the mixed refrigerant composition comprises more than one hydrocarbon components comprising methane, ethane, ethylene, propane, propylene, butanes, or any combinations thereof.
4. The process of claim 1 , wherein the mixed refrigerant composition is circulated through the at least one mixed refrigerant compressor, the at least one discharge cooler, the at least one discharge vapor/liquid separator, the first pressure control valve, and the integrated main heat exchanger.