TH74962B - Methods for olefin separation - Google Patents

Abstract

DC60 (12/07/59) This invention describes a method for separating three-carbon olefins from four-carbon olefins. Crude gas is pre-compressed (1), pre-cooled and dehydrated (2) and passed into a C3/C4 separation (6) consisting of a C4 absorber operating at a pressure of complete crude gas and a propane remover operating at a pressure of 8 to 12 bar. There, the olefins are separated into a fraction containing at least three carbon atoms (C3-) and a fraction containing at least four carbon atoms (C4+). The fraction containing at least three carbon atoms (1) is completely compressed and passed to a catalytic hydrogenation (4), while the fraction containing at least four carbon atoms is passed out for further processing (7). The fraction containing at least three carbon atoms is separated (3) at the end of the catalytic hydrogenation (4) to separate the C2/C3 into a fraction containing at least two carbon atoms (C2-), which is passed on (5) to a low-temperature separation section. and the fraction containing three carbon atoms (C3) is then passed to the fraction containing three carbon atoms for further processing (8). Revised Summary 12/07/2016 This invention describes a method for separating three-carbon olefins from four-carbon olefins. Crude gas is pre-compressed (1), pre-cooled and dehydrated (2) and passed into a C3/C4 separation (6) consisting of a C4 absorber operating at a pressure of complete crude gas and a propane remover operating at a pressure of 8 to 12 bar. There, the olefins are separated into a fraction containing at most three carbon atoms (C3-) and a fraction containing at least four carbon atoms (C4+). The fraction containing at most three carbon atoms (1) is completely compressed and passed to catalytic hydrogenation (4) while passing out the fraction containing at least four carbon atoms. For further processing (7), the fraction containing at most three carbon atoms is separated (3) at the end of the catalytic hydrogenation (4) to separate the C2/C3 into a fraction containing at least two carbon atoms (C2-), which passes on (5) to the low-temperature separation section, and a fraction containing three carbon atoms (C3), which then passes the fraction containing three carbon atoms to further processing (8). --------------------------------------------------------------------------------------------------------------- Revised 23/11/2015 This invention describes a method for separating three-carbon olefins from four-carbon olefins. The crude gas is pre-compressed (1), pre-cooled and dehydrated (2) and passed into the C3/C4 separation (6) which consists of a C4 absorber operating at a complete crude gas pressure and a propane remover operating at a pressure of 8 to 12 bar. There, the olefins are separated into a fraction containing at most three carbon atoms (C3-) and a fraction containing at least three carbon atoms (C2-). The four-carbon (C4+) fraction is completely compressed, with a maximum of three carbon atoms (1), and passed to catalytic hydrogenation (4), while passing the fraction with at least four carbon atoms out for further processing (7). The fraction with at least three carbon atoms is separated (3) at the end of the catalytic hydrogenation (4) to separate the C2/C3 into a fraction with at least two carbon atoms (C2-), which passes on (5) to the low-temperature separation section, and a fraction with three carbon atoms (C3), which is then passed to the third-carbon fraction for further processing (8). ------------------------------------------------------------------------- This invention describes a method for separating three-carbon olefins from four-carbon olefins. The crude gas is pre-compressed (1), pre-cooled and dehydrated (2), and passed into a C3/C4 separation (6) consisting of a C4 absorber operating at pressure. The crude gas is completely compressed. The propane remover, operating at a pressure of 8 to 12 bar, separates the olefin into a fraction containing at most three carbon atoms (C3-) and a fraction containing at least four carbon atoms (C4+). The fraction containing at least three carbon atoms (1) is completely compressed and passed to the catalytic hydrogenation (4), while the fraction containing at least four carbon atoms is passed out for further processing (7). The fraction containing at least three carbon atoms is separated (3) at the end of the catalytic hydrogenation (4) to separate the C2/C3 into a fraction containing at least two carbon atoms (C2-), which passes on (5) to the low-temperature separation section and the fraction containing three carbon atoms (C3), and then passes the fraction containing three carbon atoms to further processing (8).

Claims (5)

Revised 14/03/2019, Page 1 of 1. Claim 1. A method for separating three-carbon olefins from four-carbon olefins, which includes: transporting the crude gas containing the olefin hydrocarbon to a C3/C4 separation stage, which operates at the crude gas pressure. The separation column of the propane remover (P) separates olefins with a maximum of three carbon atoms and olefins with at least four carbon atoms. This propane remover (P) operates at a pressure of 8–12 bar. The crude hydrocarbon feed gas is compressed, pre-cooled, and dried before being passed to the C3/C4 separation stage. There, after pre-cooling and drying, fraction (R1) of the crude gas is passed to the absorption unit (C4A), and another fraction (R2) is passed directly to the propane remover (P). The C4 absorption unit yields a fraction with at least three carbon atoms (C3+) and another fraction with a maximum of three carbon atoms (C3-). The propane remover yields a fraction with a maximum of three carbon atoms (C3-) and another fraction with at least four carbon atoms (C4+). At least the fraction with a maximum of three carbon atoms (C3-) from the absorption unit is passed to the propane remover (P). As mentioned, and at least a portion of the separation fraction containing at most three carbon atoms (C3-) from the aforementioned propane remover is returned to the aforementioned C4 absorber. ---------------------------------------------------------------------------------------------------- Revised 12/07/2016 1. The method for separating three-carbon olefins from four-carbon olefins, which includes: introducing the hydrocarbon-protective raw gas containing olefins to the C3/C4 separation stage, which operates at the raw gas pressure and the separation column of the propane remover (P) separating olefins with at least three carbon atoms and olefins with at least four carbon atoms, the aforementioned propane remover (P) operating at a pressure of 8-12 bar, the hydrocarbon feed raw gas is compressed, pre-cooled and dried before being introduced to the C3/C4 separation stage, and where, after pre-cooling and drying, a portion (R1) of the raw gas is introduced to the absorber (C4A) and another portion (R2) of the raw gas is introduced. Directly to the aforementioned propane remover (P), the aforementioned C4 absorber yields a cleavage fraction containing at least three carbon atoms (C3+) and another cleavage fraction containing a maximum of three carbon atoms (C3-). The aforementioned propane remover yields a cleavage fraction containing a maximum of three carbon atoms (C3-) and another cleavage fraction containing at least four carbon atoms (C4+). At least one portion of such cleavage fraction containing a maximum of three carbon atoms (C3-1) from the aforementioned absorber is carried to the aforementioned propane remover (P), and at least one portion of such cleavage fraction containing a maximum of three carbon atoms (C3-1) from the aforementioned propane remover is returned to the aforementioned C4 absorber. 2. The method according to claim 1, in which at least one portion of such cleavage fraction containing a maximum of three carbon atoms (C3-) from the aforementioned absorber is compressed and subsequently taken to the hydrogenation step. Catalytic (4) --------------------------------------------- Revised 23/11/2015 1. Method for the separation of three-carbon olefins from four-carbon olefins, which consists of: introducing the hydrocarbon-protective feed gas containing the olefins to the C3/C4 separation stage, which operates at the crude gas pressure and the separation column of the propane remover (P) separating the olefins with a maximum of three carbon atoms and the olefins with a minimum of four carbon atoms, such propane remover (P) operating at a pressure of 8-12 R, the hydrocarbon feed crude gas is compressed, pre-cooled and dried before being introduced to the C3/C4 separation stage, where after pre-cooling and drying, a portion (R1X) of such crude gas is introduced to the absorption (C4A) and another portion (R2) of such crude gas is introduced Directly to the aforementioned propane remover (P), the aforementioned C4 absorber yields a fraction containing at least three carbon atoms (C3+) and another fraction containing a maximum of three carbon atoms (C3-). The aforementioned propane remover yields a fraction containing a maximum of three carbon atoms (C3-) and another fraction containing at least four carbon atoms (C4+X). At least a fraction of such fractions containing a maximum of three carbon atoms (C3-1) from the aforementioned absorber is carried to the aforementioned propane remover (P), and at least a fraction of such fractions containing a maximum of three carbon atoms (C3-1) from the aforementioned propane remover is returned to the aforementioned C4 absorber. 2. The method according to claim 1, in which at least a fraction of such fractions containing a maximum of three carbon atoms (C3-) from the aforementioned absorber is compressed and subsequently taken to the catalytic hydrogenation step (4). --------------------------------------------- 1. Method for separating three-carbon olefins from four-carbon olefins in the fractional separation stage (C3/C4 separation) in olefin production plants. From a hydrocarbon feedstock (olefin plant), long-chain olefins of the hydrocarbon feedstock are transformed into a gaseous mixture of short-chain olefin products (crude gas), which is then compressed and dried. A unique feature of the C3/C4 separation is that the crude gas is processed by an absorption unit (C4 absorption unit) operating at absolute crude gas pressure, and separation columns for olefins with a maximum of three carbon atoms and olefins with a minimum of four carbon atoms (propane remover), with the propane remover operating at pressures between 8 and 12 bar. 2. The method under claim 1, which is unique in that it involves passing the raw gas feed into a C4 absorption device. 3. Any of the methods under claims 1 and 2, which are characterized by the passage of crude gas through a C4 absorption device to separate olefins with a maximum of three carbon atoms and olefins with a minimum of three carbon atoms. 4. Any of the methods under claims 1 and 3, which are characterized by the operating pressure for the propane remover being between 8 and 12 bar. 5. Any of the methods under claims 1 and 4, which are characterized by the separation of an olefin fraction containing at least three carbon atoms by a propane remover into a fraction containing three carbon atoms and a fraction containing at least four carbon atoms.