System and process for producing hydrocarbon products

Abstract

A process for producing a petroleum product from crude oil is disclosed. A method can include subjecting a vacuum resid stream to conditions suitable for producing bitumen and hydrocarbons having a boiling temperature of less than 450 DEG C in a resid processing unit. Also disclosed is subjecting asphalt to conditions in an asphalt processing unit to produce gaseous hydrocarbons, naphtha, distillates, and coke. The gaseous hydrocarbons, naphtha, distillates, and / or coke may be converted to other products such as ethylene, propylene, MTBE, and / or alkylates.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] none Background Art A. Field of the Invention

[0002] The present invention generally relates to the production of petrochemical products from hydrocarbon feedstocks, such as crude oil. B. Description of Related Art

[0003] Systems and methods for producing hydrocarbon products have been described. For example, U.S. Patent No. 11,180,706 to Al-Saled et al. describes a configuration for olefin production. The method gradually separates crude oil into light and heavy fractions, which can be upgraded using a fixed bed hydroconversion unit, a fluidized catalytic conversion unit, or a residual oil hydrocracking unit. The upgraded fluid can be fed to a steam cracking unit for producing olefins. The process suffers from less than optimal performance, which may increase the capital cost of the entire process and reduce revenue.

[0004] In summary, while technologies exist to produce olefins, they can be energy inefficient and expensive. Summary of the invention

[0005] It has been found that at least one problem associated with producing hydrocarbon products from crude oil provides a solution. In one aspect, discovery can include processing crude oil to produce residual oil, which can be further processed into asphalt. Asphalt can be processed to produce any one, any combination or all of coke, naphtha, distillate and / or gaseous hydrocarbons. Gaseous hydrocarbons, naphtha, distillate and / or coke can be converted into other products such as ethene, propylene, MTBE and / or alkylate. Using asphalt in this way can further improve the production efficiency of petrochemicals from crude oil.

[0006] In one aspect of the invention, a method for producing hydrocarbon products is described. The method may include (a) subjecting a vacuum residue stream to conditions suitable for producing asphalt and hydrocarbons (e.g., hydrocarbons having a boiling point temperature of less than 450° C.) in a residue processing unit. In step (b), the asphalt may be subjected to conditions in an asphalt processing unit to produce gaseous hydrocarbons, naphtha, distillates and / or coke. From 6 to 10 wt.% of gaseous hydrocarbons in the asphalt processing unit, 18 to 22 wt.% of naphtha, 33 to 65 wt.% of distillates and 10 to 35 wt.% of coke may be produced. In step (c), the gaseous hydrocarbons and naphtha may be subjected to conditions suitable for producing ethylene, propylene and / or C4 hydrocarbons. In step (d), at least a portion of the C4 hydrocarbons may be subjected to the following conditions: (i) producing MTBE and / or olefins comprising 2-butene in a methyl tertiary butyl ether (MTBE) production unit, (ii) producing alkylates in an alkylate production unit, or (iii) a combination thereof. In some aspects, the vacuum residue is derived from a crude oil process that also produces light hydrocarbons and one or more distillate fractions. The light hydrocarbons may be separated to produce liquefied petroleum gas (LPG) and / or the distillate fractions may be subjected to conditions that produce naphtha, gas oil, and atmospheric distillates. LPG, naphtha, gas oil, and atmospheric distillates or a combination thereof may be provided to a steam cracking unit and subjected to conditions sufficient to produce additional ethylene, propylene, and C4 hydrocarbons. The C4 hydrocarbons may be combined with the C4 hydrocarbons of step (c). The olefins of step (d) (i) may be subjected to isomerization conditions suitable for producing 1-butene from 2-butene and residual butenes and providing 1-butene to the MTBE production unit. The residual butenes may be subjected to hydrogenation conditions suitable for producing alkanes comprising butanes, and the alkanes may be provided to a steam cracking unit. In some aspects, a portion of the produced C4 hydrocarbons may be or are hydrogenated and then may be provided to an alkylate production unit, and optionally at least a portion of the hydrogenated C4 hydrocarbons may be recycled to the steam cracking unit.

[0007] Other embodiments of the present invention are discussed throughout this application. Any embodiment discussed about one aspect of the present invention is also applicable to other aspects of the present invention, and vice versa. Each embodiment described herein is understood to be an embodiment of the present invention applicable to other aspects of the present invention. It is expected that any embodiment or aspect discussed herein can be combined with other embodiments or aspects discussed herein and / or implemented with respect to any method or composition of the present invention, and vice versa. In addition, the composition of the present invention can be used to implement the method of the present invention.

[0008] Included below are definitions of various terms and phrases used throughout this specification.

[0009] The term "C# hydrocarbons", where is a positive integer, is meant to describe all hydrocarbons having # carbon atoms. Furthermore, the term "C#+ hydrocarbons" is meant to describe all hydrocarbon molecules having # or more carbon atoms. Thus, the term "C2+ hydrocarbons" is intended to describe a mixture of hydrocarbons having 2 or more carbon atoms. The term "C2+ alkanes" therefore relates to alkanes having 2 or more carbon atoms.

[0010] The term "about" or "approximately" is defined as close to what one of ordinary skill in the art understands. In a non-limiting embodiment, the term is defined as within 10%, preferably within 5%, more preferably within 1%, and most preferably within 0.5%.

[0011] The terms "wt. %, "volume %" or "mole %" refer to the weight percent, volume percent or mole percent of a component based on the total weight, total volume or total moles of the material including the component, respectively. In a non-limiting example, 10 grams of a component in 100 grams of a material is 10 wt. % of the component.

[0012] The term "substantially" and variations thereof are defined to include ranges within 10%, within 5%, within 1%, or within 0.5%.

[0013] When used in the claims and / or specification, the terms "inhibit" or "reduce" or "prevent" or "avoid" or any variation of these terms includes any measurable reduction or complete inhibition to achieve the desired result.

[0014] The term "effective" as used in the specification and / or claims means sufficient to achieve a desired, intended, or expected result.

[0015] The use of the word "a" or "an" when used in conjunction with any of the terms "comprising," "including," "containing," or "having" in the claims or specification may mean "one," but it is also consistent with the meaning of "one or more," "at least one," and "one or more."

[0016] The words "comprise" (and any forms of including, such as "include" and "comprising"), "have" (and any forms of having, such as "have" and "having"), "include" (and any forms of including, such as "includes" and "including"), or "contain" (and any forms of containing, such as "contains" and "containing") are inclusive or open-ended and do not exclude additional unrecited elements or method steps.

[0017] The systems and methods of the present invention may "comprise," "consist essentially of," or "consist of" specific ingredients, components, compositions, etc. disclosed throughout the specification. With respect to the transitional phrase "consist essentially of," in one non-limiting aspect, the systems and methods of the present invention The fundamental and novel feature of the processes is that they are capable of producing a variety of petrochemicals from crude oil and / or bitumen derived from crude oil.

[0018] Other objects, features and advantages of the present invention will become apparent through the following drawings, detailed descriptions and examples. However, it should be understood that although the drawings, detailed descriptions and examples indicate specific embodiments of the present invention, they are given only by way of illustration and are not meant to be limiting. In addition, it is contemplated that changes and modifications within the spirit and scope of the present invention will become apparent to those skilled in the art from this detailed description. In other embodiments, features from a specific embodiment may be combined with features from other embodiments. For example, features from one embodiment may be combined with features from any other embodiment. In other embodiments, additional features may be added to the specific embodiments described herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Advantages of the present invention may become apparent to those skilled in the art having the benefit of the following detailed description and with reference to the accompanying drawings.

[0020] Figure 1 An embodiment of a system for producing hydrocarbon products from a crude oil feed is shown, the system comprising a crude oil processing unit connected to a gaseous hydrocarbon separation unit, and a steam cracking unit connected to the crude oil processing unit and the gaseous hydrocarbon separation unit. The crude oil processing unit is also connected to a resident processing unit, and the resident processing unit is connected to an asphalt processing unit.

[0021] Figure 2 is a device having additional processing units shown Figure 1 Diagram of the system.

[0022] Figure 3 Shows Figure 1 An embodiment of a system comprising a butene isomerization unit connected to a hydrogenation unit connected to a steam cracking unit.

[0023] Figure 4 Shows Figure 1 An embodiment of a system comprising an alkylation unit indirectly connected to a steam cracking unit.

[0024] While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the accompanying drawings. The drawings may not be drawn to scale. Furthermore, Figures 1 to 4 The schematic diagrams shown in can be combined with each other, which can be used, for example, to create a more robust process for producing various petrochemical products from crude oil. Detailed description of the invention

[0025] It has been found that at least one problem associated with producing valuable hydrocarbon products from crude oil provides a solution. In one aspect, crude oil can be processed to produce residual oil, which can be further processed into asphalt. Asphalt can be processed to produce any one, any combination or all of coke, naphtha, and / or gaseous hydrocarbons. These and other non-limiting aspects of the present invention are further discussed in detail with reference to the accompanying drawings in the following part.

[0026] Figure 1 and Figure 2 A system for producing valuable petroleum products from crude oil is shown. Figure 1 , a system 100 for producing petroleum products is described. Figure 2 A system 100 is shown in which various distillate processing units are provided. System 100 may include a crude oil processing unit 102, a gaseous hydrocarbon separation unit 104, a steam cracking unit 106, a residual oil hydrocracking unit 172, and an asphalt processing unit 176. Crude oil 108 enters feed separation 102. Crude oil may be an unrefined form of oil extracted from a geological formation. The term crude oil may also include oil that has undergone water-oil separation and / or gas-oil separation and / or desalting and / or stabilization. Non-limiting examples of crude oil include Arab heavy, Arab light, other Gulf crude oils, Brent, North Sea crude oil, North and West African crude oils, Indonesian crude oils, Chinese crude oils, West Texas crude oils, and mixtures thereof, and also include shale oil, asphalt sands, gas condensates, and bio-based oils. The crude oil used as the feed of the inventive method is preferably a conventional oil with an API gravity greater than 20 ° API, measured by ASTM D287 standards. On the one hand, the crude oil used for the inventive method is a light crude oil with an API gravity greater than 30 ° API. On the other hand, the crude oil used in the method of the present invention may include Arabian light crude oil. Arabian light crude oil generally has an API gravity of 32-36° API and a sulfur content of 1.5-4.5 wt%.

[0027] In the crude oil processing unit 102, at least one, two, three, four or five hydrocarbon streams (e.g., Figure 1 The light hydrocarbon stream 110, the gas oil stream 112, the residue oil stream 114, the naphtha stream 116 and the atmospheric distillate stream 118) can be produced under the conditions described above for crude oil processing (e.g., a temperature of 50°C to 700°C).

[0028] The vacuum residue stream 114 may leave the crude oil processing unit 102 and enter the residue hydrocracking unit 172. The residue hydrocracking unit 172 is capable of converting the residue into asphalt. Other hydrocarbon streams may be produced in the residue processing unit and provided to the distillate unit 130, combined with other streams, or transported to other processing units. The residue hydrocracking process is well established. For example, three basic reactor types can be used for commercial hydrocracking, which are fixed bed (trickle bed) reactor type, ebullating bed reactor type, and slurry (entrained flow) reactor type. The fixed bed residue hydrocracking process is widely accepted and is capable of processing contaminated streams such as atmospheric residue and vacuum residue to produce gas oil and naphtha. The catalyst used in the fixed bed residue hydrocracking process may include cobalt (CO), molybdenum (Mo), nickel (Ni), or a combination thereof on a refractory support (usually alumina). In the case of highly contaminated feed, the catalyst in the fixed bed residue hydrocracking process may also be supplemented to a certain extent (moving bed). The process conditions may include a temperature of 350-450° C. and a pressure of 2-20 MPa. The ebullating bed residue hydrocracking process is also well established, characterized in particular in that the catalyst is continuously replaced, allowing the treatment of highly contaminated feeds. The catalyst used in the ebullating bed residue hydrocracking process may include Co, Mo, Ni or a combination thereof on a refractory support (usually alumina). The process conditions may include a temperature of 350-450° C. and a pressure of 5-25 MPa. The slurry residue hydrocracking process represents a combination of thermal cracking and catalytic hydrogenation to achieve a high yield of distillable products from a usually highly contaminated heavy residue feed. Such a slurry residue hydrocracking process is known (e.g., US5,932,090, US2012 / 0234726A1 and WO2014142874 A1). In the first liquid stage, thermal cracking and hydrocracking reactions can occur simultaneously in a bubble slurry phase under process conditions including a temperature of 400-500°C and a pressure of 1525 MPa gauge. Residue, hydrogen, and catalyst can be introduced at the bottom of the reactor, and a bubble slurry phase can be formed; its height depends on the flow rate and the desired conversion rate. In these methods, the catalyst can be continuously replaced to achieve a consistent conversion level through the operating cycle. The catalyst can be an unsupported metal sulfide generated in situ in the reactor. The heavy distillate produced by resid reforming can be recycled to the resid hydrocracking unit 172 until it disappears.

[0029] Asphalt stream 174 can leave the residue hydrocracking unit 172 and enter the asphalt processing unit 176. In the asphalt processing unit 176, asphalt can be converted into light hydrocarbons, naphtha, distillate and petroleum coke. The amount of light hydrocarbons produced can be 6 to 10wt.%. The amount of naphtha produced can be 18-22wt%. The amount of distillate produced can be 33wt% to 65wt%. The method in the asphalt processing unit 176 can thermally crack the long-chain hydrocarbon molecules present in the asphalt stream 174 into shorter chain molecules. Light hydrocarbons can include C4 hydrocarbons, C3 hydrocarbons, C2 hydrocarbons and / or methane or a combination thereof. Light hydrocarbon stream 178, naphtha stream 180 (the fourth naphtha stream), distillate stream 182 can be sent to steam cracking unit 106 to further carry out the process. Light hydrocarbon stream 178 can also be sent to gaseous hydrocarbon separation unit 104. A combination of light hydrocarbon stream 178 and naphtha stream 180 may also be provided to gas separation unit 104. Depending on the type of distillate produced, distillate stream 182 may be provided to distillate processing unit 130 for further processing. Coke stream 184 may exit asphalt processing unit 176 and be further processed, stored, or disposed of.

[0030] Continue to refer Figure 1 , the light hydrocarbon stream 110 may include C1-C4 hydrocarbons (e.g., ethane, propane, butane, hydrogen and fuel gas) and may be provided to a gas separation device 104. In the gas separation device, the fuel gas (e.g., methane) may be separated from the C1-C4 hydrocarbons to produce C2-C4 hydrocarbons. Any conventional method suitable for separating gases may be used in the context of the present invention. Therefore, the gas may be subjected to multiple compression stages, wherein acid gases such as CO2 and H2S may be removed between compression stages. In a subsequent step, the produced gas may be partially condensed to approximately where only hydrogen remains in the gas phase at the stage of a cascade refrigeration system. The different hydrocarbon compounds may then be separated by distillation. The fuel gas stream 122 may leave the gaseous hydrocarbon separation unit 104 and be used as a fuel source in a processing unit.

[0031] The C2-C4 hydrocarbon stream 120 may leave the gaseous hydrocarbon separation unit 104 and enter the steam cracking unit 106. In the steam cracking unit 106, the C2-C4 hydrocarbon feed may be steam cracked at a pressure of 600° C. to 900° C. (e.g., 600° C., 625° C., 650° C., 675° C., 700° C., 725° C., 750° C., 775° C., 850° C., 875° C., 900° C., or any value or range therebetween) and / or 0.2 MPa to 0.3 MPa (e.g., 0.2 MPa, 0.21 MPa, 0.22 MPa, 0.23 MPa, 0.24 MPa, 0.25 MPa, 0.26 MPa, 0.27 MPa, 0.28 MPa, 0.30 MPa, or any value or range therebetween). At such temperature and pressure, the C2-C4 hydrocarbons are cracked to produce ethylene and propylene. In the steam cracking process, by diluting the mixed hydrocarbon feed with steam and heating the mixture in a furnace in the absence of oxygen, saturated hydrocarbons are decomposed into smaller, usually unsaturated hydrocarbons, such as ethylene and propylene. The steam cracking reaction can have a residence time of 50-1000 milliseconds. The steam cracking unit can include one or more furnaces to process different compositions. For example, a furnace for C2-C4 hydrocarbons and a furnace for naphtha. The steam cracking unit can have a fractionation unit (not shown) or a gas fractionation unit (not shown) that can separate ethane and / or propane from the olefin product stream. Such fractionation devices are well known in the art. Ethylene stream 126 can leave steam cracking unit 106 and store, sell or be used in other processing units. Propylene stream 128 can leave steam cracking unit 106 and store, sell or be used in other processing units.

[0032] The gas oil stream 112 and the atmospheric distillate stream 118 may exit the crude processing unit and enter a distillate processing unit 130. In the distillate processing unit 130, the steam may be further distilled and / or processed to remove impurities to form naphtha. Figure 2A detailed description of one example of different possible distillation / purification units in a distillate processing unit is depicted. The light hydrocarbon stream 134 produced in the distillate processing unit can leave the distillate processing unit 302 and enter the gas separation unit 104 and be further processed. The naphtha stream 132 can leave the distillate processing unit and enter the steam cracking unit 106. Other products can be produced in the distillate processing unit 130 (e.g., diesel, lubricating oil, etc.). The distillate processing may include one or more fixed bed catalytic reactors with one or more fractionation units to separate the desired products from the unconverted materials, and may also be combined with the ability to recycle the unconverted materials to one or both reactors. The distillate processing reactor can be operated at a temperature of 200-600°C, preferably 300-400°C, a pressure of 335MPa, preferably 5-20MPa, and 5-20wt.% hydrogen (relative to the hydrocarbon feedstock). The catalyst used in this process comprises one or more elements selected from the group consisting of Pd, Rh, Ru, Ir, Os, Cu, Co, Ni, Pt, Fe, Zn, Ga, In, Mo, W and V, which are supported in the form of metals or metal sulfides on acidic solids such as alumina, silica, alumina-silica and zeolites.

[0033] Steam cracking unit 106 can receive naphtha stream 132 and light hydrocarbon stream 120. In some aspects, naphtha stream 116 can be combined with naphtha stream 132 and / or directly provided to steam cracking unit 106. In steam cracking unit 106, naphtha stream 132 can be subjected to the aforementioned steam cracking conditions to produce ethylene, propylene and C4 hydrocarbons, Pygas and C7 / 8 hydrocarbons. Synthesis gas can include aromatics, olefins and paraffins in the range of C5s to C12s. C4 hydrocarbons can be a mixture of butadiene, butane and butene (for example, ethyl acetylene, vinyl acetylene, 1,3-butadiene, 1,2-butadiene, isobutylene, cis-2-butene, trans-2-butene, 1-butene, isobutane and normal butane). Ethylene stream 126 can leave steam cracking unit 106 and be stored, transported or used in other processing units. The propylene stream 128 may exit the steam cracking unit 106 and be stored, shipped, or used in other processing units. The C4 hydrocarbon stream 136 may exit the steam cracking unit 106 and be stored, shipped, or used in other processing units.

[0034] refer to Figure 3In system 200, a portion or all of the C4 hydrocarbons produced from steam cracking unit 106 can be further processed to produce methyl tert-butyl ether (MTBE) and other C4 hydrocarbons. In some embodiments, C4 hydrocarbons are produced by steam cracking unit 106 or different steam cracking units. C4 hydrocarbon stream 136 can leave steam cracking unit 106 and enter butadiene separation unit 138. In butadiene separation unit 138, butadiene can be separated from C4 hydrocarbons to form a butadiene composition and a butene / butane composition. Butadiene stream 140 can leave butadiene separation unit 138 and be stored, transported or used in other processing units. Butene / butane stream 142 can leave butadiene separation unit 138 and enter methyl tert-butyl ether (MTBE) production unit 144. In MTBE production unit 144, butene / butane stream 142 contacts with methanol under conditions suitable for producing MTBE, MTBE effluent and 1-butene. MTBE stream 146 can leave MTBE production unit 140 and be stored and / or transported. 1-Butene stream 148 can leave MTBE production unit 140 and be stored. Use and / or transport in other processing units. MTBE effluent 150 can leave MTBE production unit 144 and enter butene isomerization unit 152. MTBE effluent can be an enriched 2-butene stream containing 1-butene. In butene isomerization unit 152, 2-butene is contacted with a catalyst under isomerization conditions to produce a 1-butene-rich stream and a residual butene stream. The catalyst can be any known 2-butene isomerization catalyst. Isomerization conditions include a reaction temperature generally in the range of about 50° C. to 300° C. The amount of catalyst in the reactor can provide a total weight hourly space velocity of about 0.5 to 100 hours. Enriched 1-butene stream 154 can leave butene isomerization unit 152 and enter MTBE production unit 144. The residual olefin stream 156 may exit the butene isomerization unit and enter the C4 olefin hydrogenation unit 158. In the C4 olefin hydrogenation unit 158, the C4 olefins may be contacted with a catalyst and hydrogen under conditions sufficient to produce additional C4 hydrocarbons, and may optionally be recycled back to the steam cracking unit 106.

[0035] refer to Figure 4In the system 300, a portion or all of the C4 hydrocarbons produced from the steam cracking unit 106 may be further processed to produce alkylates. In some embodiments, the C4 hydrocarbons are produced by the steam cracking unit 106 or a different steam cracking unit. In the system 300, a portion or all of the C4 hydrocarbon stream 136 may leave the steam cracking unit 106 and enter the SHU (selective hydrogenation unit) 162. In the SHU 162, the C4 hydrocarbons are subjected to conditions suitable for removing alkynes and / or dienes and producing olefin compositions and additional C4 hydrocarbons. Additional C4 hydrocarbons 164 may leave the SHU 162 and enter the steam cracking unit 106 to continue the process. The olefin composition stream 166 may enter the alkylation unit 168. In the alkylation unit 168, the olefin composition is subjected to conditions for producing alkylates. The alkylation stream 170 may leave the alkylation unit 168 and be stored, transported or processed in other units. Figure 1 and Figure 2 Any or all of the parts may be Figure 3 and / or Figure 4 any or all parts of the combination and vice versa. *****

[0036] Although the embodiments and advantages thereof of the present application have been described in detail, it should be understood that various changes, substitutions and modifications may be made herein without departing from the spirit and scope of the embodiments defined by the appended claims. In addition, the scope of the present application is not intended to be limited to the specific embodiments of the processes, machines, manufactures, material compositions, means, methods and steps described in the specification. As will be readily understood by those of ordinary skill in the art from the above disclosure, the processes, machines, manufactures, material compositions, devices, methods or steps that currently exist or are developed later to perform functions substantially the same as the corresponding embodiments described herein or to achieve results substantially the same as the corresponding embodiments described herein may be utilized. Therefore, the appended claims are intended to include such processes, machines, manufactures, material compositions, means, methods or steps within their scope.

Claims

1. A method for producing a hydrocarbon product, the method comprising: (a) subjecting a vacuum residue stream to conditions suitable for producing asphalt and hydrocarbons having a boiling temperature of less than 450° C. in a residue treating unit; and (b) subjecting the asphalt to conditions in an asphalt processing unit to produce gaseous hydrocarbons, naphtha, distillate and coke.

2. The method of claim 1, further comprising: subjecting gaseous hydrocarbons and naphtha to conditions suitable for producing ethylene, propylene, and C4 hydrocarbons; and At least a portion of the C4 hydrocarbons are subjected to the following conditions: (i) in a methyl tert-butyl ether (MTBE) production unit to produce MTBE and olefins including 2-butene, (ii) in an alkylation production unit to produce alkylate, or (iii) a combination thereof.

3. The process of any one of claims 1 to 2, wherein 6-10 wt.% of gaseous hydrocarbons, 18-22 wt.% of naphtha, 33-65 wt.% of distillate and 10-35 wt.% of coke are produced.

4. The method according to any one of claims 1 to 3, further comprising obtaining the residual oil from crude oil processing, wherein the crude oil processing further produces light hydrocarbons and one or more distillate fractions.

5. The method of claim 4, further comprising separating the light hydrocarbons to produce liquefied petroleum gas (LPG).

6. The process of any one of claims 3 to 5, further comprising subjecting the distillate fraction to conditions to produce naphtha, gas oil and atmospheric distillate.

7. The method according to any one of claims 3 to 6, further comprising providing the LPG, naphtha, gas oil and atmospheric distillate to a steam cracking unit.

8. The process of any one of claims 3-7, further comprising subjecting the naphtha, gas oil, atmospheric distillate, LPG, or a combination thereof, to conditions sufficient to produce additional ethylene, propylene, and C4 hydrocarbons.

9. The process of claim 8, wherein the C4 hydrocarbons are combined with the C45 hydrocarbons of step (c).

10. The process of any one of claims 2 to 9, wherein the olefins are subjected to isomerization conditions suitable for producing 1-butene from the 2-butene and residual butenes, and the 1-butene is provided to the MTBE production unit.

11. The process of claim 10 wherein the residual butenes are subjected to hydrogenation conditions suitable for producing alkanes comprising butenes, the alkanes being provided to the steam cracking unit.

12. The process of any one of claims 1 to 11, wherein a portion of the produced C4 hydrocarbons are hydrogenated and then supplied to the alkylation process, and optionally wherein at least a portion of the hydrogenated C4 hydrocarbons are recycled to the steam cracking unit.

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