Integrated olefin recovery process

• US 8,256,243 B2
• Filed: 12/16/2006
• Issued: 09/04/2012
• Est. Priority Date: 12/16/2006
• Status: Active Grant

• Current Assignee: Kellogg Brown & Root LLC (KBR Incorporated)
• Original Assignee: Kellogg Brown & Root LLC (KBR Incorporated)
• Inventors: Verma, Vijender Kumar
• Primary Examiner(s): Jules, Frantz
• Assistant Examiner(s): Rahim, Azim Abdur
• Application Number:
  US11/639,907
• Publication Number:
  US 20080141712A1
• Time in Patent Office: 2,089 Days
• Field of Search: 626/17, 626/18, 626/19, 626/20, 626/30, 626/31
• US Class Current: 62/620
• CPC Class Codes: C07C 11/02 Alkenes
• CPC Class Codes: C07C 7/005 Processes comprising at least two steps in series
• CPC Class Codes: F25J 2200/04 in a dual pressure main column system
• CPC Class Codes: F25J 2200/30 using a side column in a single pressure column system
• CPC Class Codes: F25J 2200/74 Refluxing the column with at least a part of the partially condensed overhead gas
• CPC Class Codes: F25J 2200/76 Refluxing the column with condensed overhead gas being cycled in a quasi-closed loop refrigeration cycle
• CPC Class Codes: F25J 2200/78 Refluxing the column with a liquid stream originating from an upstream or downstream fractionator column
• CPC Class Codes: F25J 2200/94 Details relating to the withdrawal point
• CPC Class Codes: F25J 2215/62 Ethane or ethylene
• CPC Class Codes: F25J 2230/08 Cold compressor, i.e. suction of the gas at cryogenic temperature and generally without afterstage-cooler
• CPC Class Codes: F25J 2270/02 Internal refrigeration with liquid vaporising loop
• CPC Class Codes: F25J 2270/88 Quasi-closed internal refrigeration or heat pump cycle, if not otherwise provided
• CPC Class Codes: F25J 2290/40 Vertical layout or arrangement of cold equipments within in the cold box, e.g. columns, condensers, heat exchangers etc.
• 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 3/0233 separation of CnHm with 1 carbon atom or more
• 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: Y02P 20/10 Process efficiency

Abstract

Methods and apparatus for the integration of a fractionation process and an olefin refrigeration system, wherein the fractionation process olefin effluent is supplied to the refrigeration system, can eliminate a fractionation process condenser and reflux drum typically present. A plurality of bottoms streams can be collected from the fractionation process. The olefin refrigerant can be supplied to alternate olefin refrigerant consumers, as desired. A column in the fractionation process can be refluxed with an olefin stream from refrigeration system, and olefin product can be collected or exported via line.

Claims

1. A process for separating light hydrocarbons, comprising:

introducing a light hydrocarbon comprising at least one alkane component and at least one olefin component to a fractionation column to obtain an overhead olefin vapor;

introducing the overhead olefin vapor to a chiller/condenser of an olefin refrigeration compressor train at a location downstream of a compressor, wherein there is no intervening chiller/condenser located between the compressor and the chiller/condenser;

chilling and condensing the overhead olefin vapor within the olefin refrigeration compressor train to obtain liquid olefin refrigerant;

refluxing the fractionation column with a first portion of the liquid olefin refrigerant;

introducing a second portion of the liquid olefin refrigerant to additional refrigerant consumers to produce at least one olefin refrigerant vapor;

introducing the at least one olefin refrigerant vapor to the compressor; and

recovering a third portion of the liquid olefin refrigerant as an olefin product.

2. The process of claim 1, wherein the light hydrocarbon comprises propane and propylene and the fractionation column is a propane-propylene splitter.

3. The process of claim 1, wherein the light hydrocarbon comprises ethane and ethylene, and the fractionation column comprises an advanced deethanizer with the first portion of the liquid olefin refrigerant refluxing a deethanizer column and an ethylene-ethane splitter.

4. The process of claim 3, further comprising heat pumping the ethylene-ethane splitter with ethylene from the olefin refrigeration compressor train.

6. The process of claim 1, wherein the olefin refrigeration compressor train condenses an overhead vapor from a second fractionation column.

7. The process of claim 1, further comprising refluxing a second fractionation column with a third portion of the liquid olefin refrigerant.

8. The process of claim 1, wherein the additional refrigerant consumers heat and expand the second portion of the liquid olefin refrigerant to produce a plurality of olefin refrigerant vapor streams, wherein the plurality of olefin refrigerant vapor streams are introduced to the compressor.

5. An apparatus for separating light hydrocarbons, comprising:

means for introducing a light hydrocarbon comprising at least one alkane component and at least one olefin component to a fractionation column to obtain an overhead olefin vapor;

means for introducing the overhead olefin vapor to an olefin refrigeration compressor train at a location downstream of a compressor;

means for supplying the overhead olefin vapor to a chiller/condenser located downstream of the compressor with no intervening chillers/condensers between the compressor and the chiller/condenser;

means for chilling and condensing the overhead olefin vapor within the olefin refrigeration compressor train to obtain liquid olefin refrigerant;

means for refluxing the fractionation column with a first portion of the liquid olefin refrigerant;

means for expanding and heating a second portion of the liquid olefin refrigerant to form at least one olefin refrigerant vapor stream for supply to the compressor; and

means for recovering a third portion of the liquid olefin refrigerant as an olefin product.