Method and plant for obtaining crude oil products

Abstract

A method for obtaining crude oil products is proposed in which a gaseous stream (d) is formed from a first crude oil stream (b) and the gaseous stream (d) is at least partially subjected to a steam cracking process (1) in which a cracked gas stream (e) is produced which is at least partially quenched with a liquid hydrocarbon stream (f), thereby forming a quenching effluent (g). It is provided that at least part of the quenching effluent (g) is used to form a separation feed and that the separation feed is separated by distillation (5, 8) together with a second crude oil stream (c), forming distillation effluents (h, i, k, p, r). The separation feed is formed so that it contains hydrocarbons having one, two, three, four or more carbon atoms contained in the quenching effluent (g) and/or hydrocarbons formed from such hydrocarbons. The invention also relates to an apparatus (100) configured to carry out the method.

Claims

1. Method for obtaining crude oil products wherein a gaseous stream (d) is formed from a first crude oil stream (b) and the gaseous stream (d) is at least partly subjected to a steam cracking process (1), wherein, in the steam cracking process (1), a cracked gas stream (e) is produced which is at least partly quenched with a liquid hydrocarbon stream (f), with formation of a quenching effluent (g), characterised in that at least part of the quenching effluent (g) is used to form a separation feed and that the separation feed is separated (5, 8) by distillation together with a second crude oil stream (c), forming distillation effluents (h, i, k, p, r), the separation feed being formed such that it contains hydrocarbons contained in the quenching effluent (g) having one, two, three, four or more carbon atoms and/or hydrocarbons formed from hydrocarbons of this kind.

2. Method according to claim 1, wherein the separation feed is formed so that it contains hydrocarbons which were previously contained in the liquid hydrocarbon stream (f) used for the quenching, or contains compounds formed from such hydrocarbons.

3. Method according to claim 1, wherein the distillation effluents (h, i, k, p, r) or streams (s, t, w, z) derived therefrom are at least partly subjected to the steam cracking process (1) as recycle streams.

4. Method according to claim 1, wherein atmospheric gas oil (i) treated by catalytic hydrogenation (11), vacuum gas oil (r) treated by catalytic hydrogenation, saturated hydrocarbons having two to four carbon atoms (z) and/or hydrocarbons having five to eight carbon atoms (w) are used as recycle streams subjected to the steam cracking process (1).

5. Method according to claim 1, wherein the gaseous stream (d) is formed by evaporation (2) from the first crude oil stream (b), while a fraction (f) which remains liquid during the evaporation (2) is used at least partly to form the liquid hydrocarbon stream (f) used for the quenching.

6. Method according to claim 1, wherein the liquid hydrocarbon stream (f) used for the quenching is low in or free from components that have been separated from the quenching effluent (g) or from a stream formed from the quenching effluent (f).

7. Method according to claim 1, wherein the distillative separation (5, 8) of the separation feed together with the second crude oil stream (c) is carried out initially at atmospheric pressure (5) and subsequently under vacuum (8).

8. Method according to claim 1, wherein at least streams (s, t) derived by catalytic hydrogenation (10, 11) are formed from at least a proportion of the distillation effluents (i, r).

9. Method according to claim 1, wherein methane, ethylene, propylene and/or butadiene (x) and/or aromatic compounds (v) are obtained.

10. Method according to claim 1, wherein at least a proportion of the distillation effluents (p, y) is burned to recover energy.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows an apparatus for recovering crude oil products according to one embodiment of the invention, in partial view.

(2) FIG. 2 shows an apparatus for recovering crude oil products according to one embodiment of the invention, in an expanded view.

(3) In the Figures, elements corresponding to one another have been given identical reference numerals and are not repeatedly explained. The components of the apparatus shown simultaneously correspond to steps of a process.

EMBODIMENTS OF THE INVENTION

(4) FIG. 1 schematically shows, in partial view, an apparatus, generally designated 100, for producing crude oil products according to one embodiment of the invention.

(5) Crude oil a supplied to the apparatus 100 is divided into two crude oil streams b and c. The crude oil stream b is preheated in a convection zone of one or more cracking furnaces 1 and transferred into an evaporation vessel 2. A portion of the crude oil stream b which evaporates in the evaporation vessel 2 is passed, as stream d, after mixing with steam, through the radiation zone of the cracking furnace or furnaces 1, and a cracked gas e is obtained.

(6) The cracked gas e is cooled in a cracked gas cooler 3 and then quenched in a quenching device 4 with a portion of the crude oil stream b, illustrated here by the stream f, which has remained liquid in the evaporation vessel 2. A separation feed (not specifically shown) formed from the quenching effluent g is transferred into a distillation column 5 for fractional atmospheric distillation, into which the crude oil stream c is also fed.

(7) The distillation column 5 is operated in the conventional manner, so that, for example, an atmospheric residue h and an atmospheric gas oil i are obtained therein. From the top, or from an upper part of the distillation column 5, a stream k is drawn off which contains light products from the cracking furnace or furnaces 1 and the crude oil stream c. By the admixture of water (not shown) in a water washer 6, a water-naphtha mixture is precipitated from the stream k and transferred as stream l into a decanter 7. In this decanter, a water stream m and a naphtha stream n are obtained.

(8) Fractions remaining in gaseous form in the water washer 6, which are essentially hydrocarbons with one to four carbon atoms, are drawn off as stream o and fed into a fractionation section which may be of known configuration. In a corresponding fractionation section, for example, first of all methane and/or methane and ethane may be separated off (so-called Demethanizer First or Deethanizer First process).

(9) FIG. 2 shows the apparatus 100 in expanded view, i.e. as an enlarged detail, generally designated 200, of a complete apparatus 100. The part of the apparatus shown in FIG. 1, i.e. at least one cracking furnace 1 with the associated devices 2 to 4 and a distillation column 5 configured for fractional atmospheric distillation, having a water washer 6 and an associated decanter 7, is designated 100.

(10) As shown in FIG. 2, a vacuum residue p is obtained from an atmospheric residue which is drawn off from the distillation column 5 as stream h, in a distillation column 8 configured for vacuum distillation; this vacuum residue p can be burned in a device 9 and used to recover energy, as indicated by arrow q.

(11) An overhead stream r from the distillation column 8, so-called vacuum gas oil, is transferred into a hydrogenation unit 10 where the stream r may be processed by hydrocracking, for example. A correspondingly processed stream s can be recycled into the steam cracking process or into one or more cracking furnaces 1. The same also applies to the above-mentioned stream i, the atmospheric gas oil, which can be treated in a hydrogenation unit 11 and then recycled as stream t into the steam cracking process. From a stream u, which essentially contains hydrocarbons having five to eight carbon atoms, aromatic compounds can be separated off in an aromatics extraction unit 12 and discharged from the apparatus as stream v. A remaining fraction can be subjected to another steam cracking process as stream w. The stream o described hereinbefore, which predominantly comprises hydrocarbons having one to four carbon atoms, can be transferred into a C4 fractionation section 13 in which the product streams which are here generally designated x, such as ethylene, propylene and butadiene, for example, can be separated off. A methane stream y can be discharged from the apparatus and/or used for heating. Hydrocarbons not obtained as product streams x may be recycled into the steam cracking process as stream z.