Isobutane flashing in the alkylation of c{11 {14 c{11 {0 olefin hydrocarbons with isobutane

Claim 2

IN THE ALKYLATION OF ISOBUTANE WITH C2, C3 AND/OR C5 OLEFINS, THE IMPROVEMENT COMPRISING, REMOVING N-BUTANE FROM A PARAFFIN FEED STOCK CONTAINING A MAJOR PROPORTION OF ISOBUTANE, ALKYLATING SAID ISOBUTANE-CONTAINING FEED STOCK, CONTAINING ESSENTIALLY NO N-BUTANE, WITH AN OLEFIN ALKYLATING AGENT, ESSENTIALLY FREE OF N-BUTANE, SELECTED FROM THE CLASS CONSISTING OF ETHYLENE, PROPYLENE, AMYLENES AND MIXTURES THEREOF, IN THE PRESENCE OF AN ACID CATALYST, SEPARATING THE CATALYST FROM THE ALKYLATION REACTION MIXTURE, FLASHING THE CATALYST-FREE ALKYLATION REACTION MIXTURE TO REMOVE A PORTION OF THE UNREACTED ISOBUTANE AS AN OVERHEAD FRACTION AND TO SEPARATE THE ALKYLATE AND THE REMAINING UNREACTED ISOBUTANE AS A BOTTOM FRACTION, FLASHING SAID ALKYLATE AND SAID REMAINING UNREACTED ISOBUTANE TO REMOVE A MAJOR PROPORTION OF SAID REMAINING UNREACTED ISOBUTANES AS AN OVERHEAD FRACTION, WITHDRAWING SAID ALKYLATE, AND RECYCLING THE RECOVERED ISOBUTANE.

Claim 3

In the alkylation of isobutane with ethylene, propylene, amylenes or mixtures thereof, the improvement comprising, removing n-butane from a paraffin feed stock containing a major proportion of isobutane and minor amounts of n-butane, alkylating in a first alkylation reactor the isobutane feed stock, essentially free of n-butane, with an alkylating agent, essentially free of n-butane, selected from the class consisting of ethylene, propylene, amylenes and mixtures thereof, in the presence of an acid alkylation catalyst, separating the catalyst from the alkylation reaction mixture, flashing the catalyst-free alkylation reaction mixture to remove a portion of the unreacted isobutane as an overhead fraction and to separate the alkylate and the remaining unreacted isobutane as a bottom fraction, flashing said alkylate and said remaining unreacted isobutane to remove a major proportion of said remaining unreacted isobutane as an overhead fraction withdrawing said alkylate, recycling a major proportion of the recovered unreacted isobutane to said first alkylation reactor, and passing the remaining portion of said recovered isobutane as isobutane feed to a second alkylation reactor having a conventional deisobutanizer for separating isobutane and n-butane from the second alkylation reaction mixture of isobutane with butylenes.

Claim 4

In the alkylation of isobutane with ethylene, propylene, amylenes or mixtures thereof, the improvement comprising, removing n-butane from a paraffin feed stock containing a major proportion of isobutane and minor amounts of n-butane, alkylating in a first alkylation reactor the isobutane feed stock, essentially free of n-butane, with an alkylating agent, essentially free of n-butane, selected from the class consisting of ethylene, propylene, amylenes and mixtures thereof, in the presence of an acid alkylation catalyst, separating the catalyst from the alkylation reaction mixture, flashing the catalyst-free alkylation reaction mixture to remove a portion of the unreacted isobutane as an overhead fraction and to separate the alkylate and the remaining unreacted isobutane as a bottom fraction, flashing said alkylate and said remaining unreacted isobutane to remove a major proportion of said remaining unreacted isobutane as an overhead fraction withdrawing said alkylate, recycling a major proportion of the recovered unreacted isobutane to said first alkylation reactor, and passing the remaining portion of said recovered isobutane as isobutane feed to a second alkylation reactor having a conventional deisobutanizer for separating isobutane and n-butane from the second alkylation reaction mixture of isobutane with butylenes.

Claim 5

The process of claim 2, wherein the alkylating agent is propylene and the catalyst is sulfuric acid of at least about 80 percent strength.

Claim 6

The process of claim 2, wherein the alkylating agent is amylenes and the catalyst is sulfuric acid of at least about 80 percent strength.

Claim 7

The process of claim 2, wherein the alkylating agent is a mixture of propylene and amylenes, and the catalyst is sulfuric acid of at least strength. 80 Percent strength.

Claim 8

The process of claim 2 wherein the alkylating agent is propylene and the catalyst is hydrofluoric acid.

Claim 9

The process of claim 2 wherein the alkylating agent is amylenes and the catalyst is hydrofluoric acid.

Claim 10

The process of claim 2 wherein the alkylating agent is a mixture of propylene and amylenes and the catalyst is hydrofluoric acid.

Claim 11

The process of claim 2, wherein the n-butane is removed from the paraffin feed stock by means of molecular sieves.

Claim 12

The process of claim 9, wherein the molecular sieves are adsorbents having pore sizes of about 5.0 - 5.5 Angstrom units.

Claim 13

In the alkylation of isobutane with propylene, amylenes and mixtures thereof, the improvement comprising, removing n-butane from a paraffin stock containing a major proportion of isobutane and minor amounts of n-butane, alkylating in a first alkylation reactor said isobutane-containing paraffin stock, essentially free of n-butane, with an olefin alkylating agent, essentially free of n-butane, selected from the class consisting of propylene, amylenes and mixtures thereof, in the presence of an acid alkylation catalyst, separating catalyst from the alkylation reaction mixture, flashing the catalyst-free alkylation mixture to remove propane and a portion of the unreacted isobutane as an overhead fraction and to recover the alkylate and the remaining unreacted isobutane as a bottom fraction, depropanizing said overhead fraction to remove said propane and to recover unreacted propane-free isobutane, flashing said bottom fraction to separate a major proportion of said remaining unreacted isobutane therefrom, withdrawing said alkylate, combining said recovered unreacted propane-free isobutane and said recovered remaining unreacted isobutane, recycling a major proportion of said combined recovered unreacted isobutane to said first alkylation reactor, and passing the remaining portion of said combined recovered unreacted isobutane as isobutane feed to a second alkylation reactor having a conventional deisobutanizer for separating isobutane and n-butane from second alkylation reaction mixture of isobutane with butylenes.

Claim 14

In the alkylation of isobutane with propylene, amylenes and mixtures thereof, the improvement comprising, removing n-butane from a paraffin stock containing a major proportion of isobutane and minor amounts of n-butane, alkylating in a first alkylation reactor said isobutane-containing paraffin stock, essentially free of n-butane, with an olefin alkylating agent, essentially free of n-butane, selected from the class consisting of propylene, amylenes and mixtures thereof, in the presence of an acid alkylation catalyst, separating catalyst from the alkylation reaction mixture, flashing the catalyst-free alkylation mixture to remove propane and a portion of the unreacted isobutane as an overhead fraction and to recover the alkylate and the remaining unreacted isobutane as a bottom fraction, depropanizing said overhead fraction to remove said propane and to recover unreacted propane-free isobutane, flashing said bottom fraction to separate a major proportion of said remaining unreacted isobutane therefrom, withdrawing said alkylate, combining said recovered unreacted propane-free isobutane and said recovered remaining unreacted isobutane, recycling a major proportion of said combined recovered unreacted isobutane to said first alkylation reactor, and passing the remaining portion of said combined recovered unreacted isobutane as isobutane feed to a second alkylation reactor having a conventional deisobutanizer for separating isobutane and n-butane from second alkylation reaction mixture of isobutane with butylenes.

Claim 15

The process of claim 11, wherein the n-butane is removed from the paraffin feed stock by means of adsorbents having pore sizes in the range of about 5.0 - 5.5 Angstroms, and the catalyst is sulfuric acid of at least 80 percent strength.

Claim 16

The process of claim 11, wherein the acid catalyst is hydrofluoric acid.

Claim 17

In the alkylation of isobutane with ethylene, propylene, amylenes or mixtures thereof, the improvement comprising, removing n-butane from a paraffin feed stock containing a major portion of isobutane and minor amounts of n-butane, alkylating in a first alkylation reactor the isobutane feed stock, essentially free of n-butane, with an alkylating agent, essentially free of n-butane, selected from the class consisting of ethylene, propylene, amylenes and mixtures thereof, in the presence of aluminum chloride catalyst and complexes thereof, separating the catalyst from the alkylation reaction mixture, flashing the catalyst-free alkylation reaction mixture to remove a portion of the unreacted isobutane as an overhead fraction and to separate the alkylate and the remaining unreacted isobutane as a bottom fraction, flashing said alkylate and said remaining unreacted isobutane to remove a major portion of said remaining unreacted isobutane as an overhead fraction, withdrawing said alkylate, recycling a major portion of the recovered unreacted isobutane to said first alkylation reactor, and passing the remaining portion of said recovered isobutane as isobutane feed to a second alkylation reactor having a conventional deisobutanizer for separating isobutane and n-butane from the second alkylation mixture of isobutane with butylenes.

Claim 18

In the alkylation of isobutane with ethylene, propylene, amylenes or mixtures thereof, the improvement comprising, removing n-butane from a paraffin feed stock containing a major portion of isobutane and minor amounts of n-butane, alkylating in a first alkylation reactor the isobutane feed stock, essentially free of n-butane, with an alkylating agent, essentially free of n-butane, selected from the class consisting of ethylene, propylene, amylenes and mixtures thereof, in the presence of aluminum chloride catalyst and complexes thereof, separating the catalyst from the alkylation reaction mixture, flashing the catalyst-free alkylation reaction mixture to remove a portion of the unreacted isobutane as an overhead fraction and to separate the alkylate and the remaining unreacted isobutane as a bottom fraction, flashing said alkylate and said remaining unreacted isobutane to remove a major portion of said remaining unreacted isobutane as an overhead fraction, withdrawing said alkylate, recycling a major portion of the recovered unreacted isobutane to said first alkylation reactor, and passing the remaining portion of said recovered isobutane as isobutane feed to a second alkylation reactor having a conventional deisobutanizer for separating isobutane and n-butane from the second alkylation mixture of isobutane with butylenes.

Claim 19

The alkylation process comprising, introducing into a first alkylation reactor a paraffin feed stock containing a major amount of isobutane And a minor amount of n-butane, alkylating the isobutane in said feed stock with butylenes in the presence of an acid alkylation catalyst selected from the class consisting of sulfuric acid and hydrofluoric acid, separating catalyst from the alkylation reaction mixture, introducing the resultant alkylation reaction mixture from said first alkylation reactor into a conventional deisobutanizer to withdraw alkylate and to separate unreacted isobutane as an overhead fraction, passing said overhead fraction through molecular sieves having a pore size of 5.0 to 5.5 Angstrom units to produce recovered unreacted isobutane containing essentially no n-butane, combining said recovered unreacted isobutane, containing essentially no n-butane, with sufficient make-up isobutane, essentially free of n-butane, from an external source, introducing said combined recovered unreacted isobutane and make-up isobutane into a second alkylation reactor, alkylating said combined recovered unreacted isobutane and make-up isobutane with an olefin alkylating agent, essentially free of n-butane, selected from the class consisting of propylene, amylenes and mixtures thereof, in the presence of an acid alkylation catalyst, the ratio of isobutane to olefin in said second alkylation reaction being maintained in the ratio of from about 5:1 to about 30:1, withdrawing the resultant alkylation reaction mixture from said second alkylation reactor, separating the catalyst from the alkylation mixture, flashing the catalyst-free alkylation reaction mixture to remove and recover a portion of the uncombined isobutane as an overhead fraction and to separate the alkylate and the remaining uncombined isobutane as a bottom fraction, flashing said alkylate and said remaining uncombined isobutane to remove and recover a major proportion of said remaining uncombined isobutane as an overhead fraction, withdrawing said alkylate and recycling said recovered uncombined isobutane to said second alkylation reactor.

Claim 20

The alkylation process comprising, introducing into a first alkylation reactor a paraffin feed stock containing a major amount of isobutane And a minor amount of n-butane, alkylating the isobutane in said feed stock with butylenes in the presence of an acid alkylation catalyst selected from the class consisting of sulfuric acid and hydrofluoric acid, separating catalyst from the alkylation reaction mixture, introducing the resultant alkylation reaction mixture from said first alkylation reactor into a conventional deisobutanizer to withdraw alkylate and to separate unreacted isobutane as an overhead fraction, passing said overhead fraction through molecular sieves having a pore size of 5.0 to 5.5 Angstrom units to produce recovered unreacted isobutane containing essentially no n-butane, combining said recovered unreacted isobutane, containing essentially no n-butane, with sufficient make-up isobutane, essentially free of n-butane, from an external source, introducing said combined recovered unreacted isobutane and make-up isobutane into a second alkylation reactor, alkylating said combined recovered unreacted isobutane and make-up isobutane with an olefin alkylating agent, essentially free of n-butane, selected from the class consisting of propylene, amylenes and mixtures thereof, in the presence of an acid alkylation catalyst, the ratio of isobutane to olefin in said second alkylation reaction being maintained in the ratio of from about 5:1 to about 30:1, withdrawing the resultant alkylation reaction mixture from said second alkylation reactor, separating the catalyst from the alkylation mixture, flashing the catalyst-free alkylation reaction mixture to remove and recover a portion of the uncombined isobutane as an overhead fraction and to separate the alkylate and the remaining uncombined isobutane as a bottom fraction, flashing said alkylate and said remaining uncombined isobutane to remove and recover a major proportion of said remaining uncombined isobutane as an overhead fraction, withdrawing said alkylate and recycling said recovered uncombined isobutane to said second alkylation reactor.

Claim 21

The process of claim 15 wherein said make-up isobutane essentially free of n-butane, from an external source, is obtained by passing an external paraffin stream containing isobutane and n-butane into a conventional deisobutanizer, separating therein isobutane from the external paraffin stream, recovering the isobutane as an overhead fraction, introducing said overhead fraction into molecular sieves having a pore size of 5.0 to 5.5 Angstrom units, and withdrawing the isobutane, essentially free of n-butane, from the molecular sieves.