SEPARATION OF GASES

• US 3,729,944 A
• Filed: 07/23/1970
• Issued: 05/01/1973
• Est. Priority Date: 07/23/1970
• Status: Expired due to Term

• Current Assignee: Carl S. Kelley, Frank H. Thorn
• Original Assignee: Carl S. Kelley, Frank H. Thorn
• Inventors: Kelley, Carl S., Thorn, Frank H.
• Primary Examiner(s): Yudkoff, Norman
• Assistant Examiner(s): Purcell, Arthur F.
• Application Number:
  US05/057,493
• Time in Patent Office: 1,013 Days
• Field of Search: 62/23,24,27,28,39,26 260/677A,679A
• US Class Current: 62/630
• CPC Class Codes: C07C 7/005 Processes comprising at least two steps in series
• CPC Class Codes: F25J 2210/12 Refinery or petrochemical off-gas
• CPC Class Codes: F25J 2215/62 Ethane or ethylene
• CPC Class Codes: F25J 2245/02 Recycle of a stream in general, e.g. a by-pass stream
• CPC Class Codes: F25J 2270/02 Internal refrigeration with liquid vaporising loop
• CPC Class Codes: F25J 2270/04 Internal refrigeration with work-producing gas expansion loop
• CPC Class Codes: F25J 3/0219 Refinery gas, cracking gas, coke oven gas, gaseous mixtures containing aliphatic unsaturated CnHm or gaseous mixtures of undefined nature
• CPC Class Codes: F25J 3/0238 separation of CnHm with 2 carbon atoms or more
• CPC Class Codes: F25J 3/0242 separation of CnHm with 3 carbon atoms or more
• CPC Class Codes: F25J 3/0252 separation of hydrogen production of hydrogen containing gas in general C01B3/00, e.g. separation of hydrogen or hydrogen containing gases form gaseous mixtures at low temperatures C01B3/506

Abstract

A gas-liquid mixture is introduced into a phase separation zone wherein there is effected a separation between a gas phase and its equilibrium liquid; the gas phase is required to perform a maximum of expansion work and then passed in indirect heat exchange with the gas-liquid mixture; the desired cooling of the gas-liquid mixture not completely supplied by the gas phase is supplied by a portion of the equilibrium liquid with the remaining portion of the equilibrium liquid being passed to convenient locations for further processing.

Claims

2. The process of claim 1 wherein said portion of said third liquid stream is combined with said first liquid stream and introduced into said first fractionating zone.

3. The process of claim 1 wherein said portion of said third liquid stream is combined with said second gas stream.

4. The process of claim 2 wherein said first gas-liquid stream is comprised essentially of hydrogen, methane, ethylene, and ethane, said second liquid stream is comprised essentially of ethylene and ethane, and said tail gas stream is comprised essentially of hydrogen and methane.

5. The process of claim 4 wherein a gaseous feedstream comprising ethane is introduced into a cracking zone wherein said feedstream is subjected to heat sufficient to convert it to a cracked gas stream comprised of carbon dioxide, hydrogen, methane, acetylene, ethylene, ethane, propylene, propane, and higher-boiling hydrocarbons up to hydrocarbons having six carbon atoms per molecule, introducing said cracked gas stream into a compression zone wherein said cracked gas stream is compressed, cooled and condensed to form a fourth liquid stream, introducing fourth liquid stream into a second fractionating zone wherein a fifth liquid stream comprising C3 and C4 hydrocarbons and a fourth gas stream are produced, and introducing said fourth gas stream into a second compression zone wherein said fourth gas stream is compressed, cooled, and partially condensed to form said first gas-liquid stream.

6. The process of claim 5 wherein at least a portion of said third liquid stream passing in said heat exchange zone is thereafter introduced into a third compression zone wherein said third liquid stream is compressed as a result of the expansion work performed by said tail gas.

7. The process of claim 6 wherein at least a portion of said cracked gas is compressed in said third compression zone.