RU2000106432A - Catalytic distillation and hydrogenation of heavy unsaturated products in a plant for the production of olefins - Google Patents

Claims (15)

1. A method of processing cracked starting material containing hydrogen, C ₂ components, including ethylene, C ₃ components, including propylene, acetylenes and dienes, C ₄ and C ₅ components, including acetylenes, dienes and olefins, and C ₆ or more high molecular weight components, including the unsaturated compound to isolate it from ethylene and propylene and the hydrogenation of C ₃ acetylenes and dienes to produce additional propylene by hydrogenation of at least some of the C ₄ - and C ₅ acetylenes, dienes and olefins to saturated compounds and hydrogenated C ₆ - and higher molecular weight unsaturated compounds to the mixture of olefins and saturates without appreciable hydrogenation of ethylene and propylene comprising the steps of
a. evolution of hydrogen and C ₂ components;
b. the selection of ethylene as a product from the selected C ₂ components;
in. the introduction of material with C ₃ - and higher molecular weight components and a certain amount of hydrogen into the input zone of the starting material of the distillation column, including an enrichment section above the input zone of the source material and a section for stripping light fractions under the input zone of the source material, at least in the enrichment sections contain a hydrogenation catalyst;
d. separation by distillation of C ₆ and higher molecular weight unsaturated components in the form of bottoms;
e. the introduction of C ₆ and higher molecular weight unsaturated components in the form of bottoms into contact with hydrogen and a hydrogenation catalyst, as a result of which these C ₆ and higher molecular weight unsaturated components are hydrogenated to C ₆ and higher molecular weight olefins and saturated compounds;
E. the distillation of the C ₃ -, C ₄ - and C ₅ components with the simultaneous introduction of these C ₃ -, C ₄ - and C ₅ components in contact with the hydrogenation catalyst in the concentration zone to obtain the overhead and maintain conditions in the concentration zone, including concentration hydrogen created by said amount of hydrogen introduced, whereby C ₃ acetylenes and dienes are hydrogenated to form an additional amount of propylene and as a result C ₄ - and C ₅ acetylenes, dienes and olefins are at least partially hydrogenated, and
g. separation and isolation from the overhead product of propylene and further hydrogenation of the at least partially hydrogenated C ₄ - and C ₅ acetylenes, dienes and olefins contained in this overhead product to produce saturated C ₄ - and C ₅ compounds. 2. The method according to claim 1, in which the stripping section of the light fractions also includes a hydrogenation catalyst, and in which the aforementioned stages (g) and (e) of distillation and hydrogenation of C ₆ and higher molecular weight components are carried out simultaneously in the stripping section of the light fractions. 3. The method according to p. 2, in which the stage of separation of propylene is a stage of separation into fractions with the separation of propylene from C ₄ - and C ₅ components. 4. The method according to p. 3, in which the C ₆ - and higher molecular weight components include C ₆ -C ₈ components and C ₉ - and higher molecular weight components and which further includes the step of separating the bottoms into fractions, separation of the overhead, including almost all C ₆ -C ₈ components, and still bottoms, including almost all C ₉ - and higher molecular weight components, and further hydrogenation of the overhead with C ₆ -C ₈ components. 5. The method of claim. 2, wherein the starting material is cracked further includes heavy cracked gasoline, wherein prior to step (a) separating the C ₂ components from the cracked feedstock emit at least part of this heavy cracked-gasoline and which further comprises the step of feeding the selected heavy cracked gasoline together with C ₃ - and higher molecular weight components and hydrogen to the distillation column. 6. The method according to p. 1, in which stage (a) separation of C ₂ components from the starting material to obtain the remaining material with C ₃ and higher molecular weight components and stage (c) of introducing this material with C ₃ and higher high molecular weight components and hydrogen in a distillation column containing a hydrogenation catalyst include the step of introducing this starting material into the distillation column, the upper part of which includes a distillation section for the separation of C ₂ components, and the lower part including It contains a reaction-distillation section containing the specified catalyst for the joint isolation of C ₂ components and hydrogenation of C ₃ and higher molecular weight components. 7. The method according to p. 1, in which a cracked gaseous starting material is obtained at the cracking stage of a hydrocarbon starting material, in which C ₃ and higher molecular weight components further include propane and in which said stages of distillation of the material with C ₃ and higher molecular weight components include the stage of separation of propane and saturated C ₄ - and C ₅ components and the return of the selected propane and saturated C ₄ - and C ₅ components to the cracking stage. 8. The method according to p. 2, in which stages (d) and (e) distillation and hydrogenation of C ₆ and higher molecular weight components in the stripping section of the light fractions further include a pumping step, bypassing the material from a point below the hydrogenation catalyst of the lung stripping section fractions to a point above the hydrogenation catalyst of the stripping section of light fractions.  9. The method of claim 8, wherein the hydrogenation catalyst for the light stripping section comprises an upper section of a hydrogenation catalyst and a lower section of a hydrogenation catalyst, and in which this upper section contains a hydrogenation catalyst in the presence of a less active hydrogenation catalyst in the lower section.  10. The method according to p. 9, which further includes the stage of pumping with the supply of material bypassing from a point below the upper section to a point above the upper section. 11. The method according to p. 1, in which stage (g) of the separation of propylene from the overhead includes the following stages (I) introducing the overhead into the feed zone of the second reactive distillation column, comprising an enrichment section above the feed zone and a stripping section light fractions below the input zone of the starting material, the stripping section of the light fractions of which contains a hydrogenation catalyst, (II) introducing hydrogen into the second reactive distillation column at a point below the hydrogenation catalyst, (III) distillation the propylene overhead and hydrogenation of the C ₃ -, C ₄ - and C ₅ components. 12. The method according to p. 1, in which stage (g) separation of propylene from the overhead includes the following stages (I) introducing the overhead into the feed zone of the second reactive distillation column, comprising a concentration section above the input zone of the starting material and the stripping section light fractions below the feed zone, the stripping section of the light fractions of which contains a hydrogenation catalyst, (II) introducing hydrogen into the second reactive distillation column at a point below the hydrogenation catalyst, (III) introducing the material with C ₃ - and higher molecular weight components in a series of reactive distillation columns comprising at least one reactive distillation concentration section containing a hydrogenation catalyst, and at least one reactive distillation section of the stripping of light fractions containing a hydrogenation catalyst , (IV) introducing hydrogen into the reactive distillation enriching section and the stripping section, (V) hydrogenation of at least C ₃ acetylenes and dienes to propylene in one from the reactive distillation concentrating sections without hydrogenating the propylene, (VI) at least partial hydrogenation of the C ₄ - and C ₅ acetylenes, dienes and olefins to saturated compounds in a reaction-distillation sections, (VII) distilling propylene as a product from C ₄ - and C ₅ components and (VIII) hydrogenation of C ₆ - and higher molecular weight unsaturated components in one of the reaction-distillation sections of the stripping of light fractions. 13. A method for processing cracked gaseous starting material containing unsaturated C ₃ components, including propylene, acetylenes and dienes, unsaturated C ₄ - and C ₅ components, including acetylenes, dienes and olefins, with the aim of hydrogenating C ₃ acetylenes and dienes and hydrogenating at least least one unsaturated C ₄ - and C ₅ unsaturated components without hydrogenation of propylene by selective hydrogenation of C ₃ acetylenes and dienes in a first catalytic distillation bed in the first catalytic distillation installation, whereby n Luciano additional propylene, distilling off of propylene and an additional amount of propylene as overhead and produce a material comprising unsaturated C ₄ - and C ₅ components and non-selective hydrogenation of at least one unsaturated C ₄ components and unsaturated C ₅ components in the second layer catalytic distillation in a second catalytic distillation unit.  14. The method according to p. 13, in which the first catalytic distillation layer is in the enrichment section of the first catalytic distillation unit, and the second catalytic distillation layer is in the enrichment section of the second catalytic distillation unit.  15. The method according to p. 13, in which the first catalytic distillation layer is in the enrichment section of the first catalytic distillation unit, and the second catalytic distillation layer is in the light stripping section of the second catalytic distillation unit.