Hydrocarbon resid processing and visbreaking steam cracker feed

This application claims the rights and priority of US Provisional Patent Application No. 60/728,640 (2005B125) filed on October 20, 2005, and also claims 2006 The rights of US provisional patent application number 60/813, 555 (2006B101) filed on June 14.

TECHNICAL FIELD The present invention relates to a method for preparing alkene from crude oil or its residual oil-containing fillings.

BACKGROUND OF THE INVENTION Thermal cracking of jasmines is a petrochemical process widely used in the preparation of olefins such as ethylene, propylene, butenes, butadiene, and aromatics such as benzene, toluene and xylenes. Each of these compounds is a valuable industrial product. For example, light olefin paint can be oligomerized (for example, oligomerized as lubricant base oil), polymerized (for example, polymerized into polyethylene, polypropylene and other plastics) and/or functionalized (for example, used to form acids, alcohols, aldehydes, etc.) , The listed materials all have known intermediate and/or end uses. One type of thermal cracking method is steam cracking, which involves cracking monsters in the presence of hydrogen and/or hydrogen-containing components such as steam.

The starting materials of the conventional olefin production equipment as described above have undergone extensive (and high-cost) processing before reaching the olefin production equipment. Normally, whole crude oil is steamed or otherwise filled or cracked into multiple parts (filling) such as gasoline, kerosene, naphtha, gas oil (vacuum gas oil and atmospheric gas oil), etc. (including high boiling point residues) The oil ("residual oil")) is desalinated first. Residual oil fillings usually have a boiling point above 650°F (343°F) at atmospheric pressure. Usually after desalination and removal of residual oil fillings, any of these fillings except for 650°F+ (343°F+) residual oil can be transported to a steam cracker or olefin production unit as the raw material of the unit.

Generally, in steam cracking, steam cracking uses hydrocarbon raw materials such as naphtha, gas oil or

200680038858.0 Other fractions of the whole crude oil that do not contain residual oil (they can be obtained by steaming or otherwise filling whole crude oil, for example) are introduced into the steam cracker, usually mixed with steam. Ordinary steam cracking uses a pyrolysis furnace that usually has two main sections: a convection section and a radiant section. In an ordinary pyrolysis furnace, the raw material enters the convection section of the pyrolysis furnace which is not strictly strict as a liquid (except for the light raw materials entering as steam), where it is indirectly contacted and freed by the hot flue gas from the radiant section. The option is heated and vaporized by direct contact with steam. The vaporized feedstock and steam mixture (if present) is then introduced into the radiant section through a jumper, where it is rapidly heated to a strict cracking temperature of osmanthus, for example, 1450°F (788°C) at a pressure of usually 10-30 psig To the range of 1550°F (843°C) to provide thorough thermal cracking of the feed stream. The resulting product containing alkene leaves the pyrolysis furnace for further downstream separation and processing.

After cracking, the effluent of the pyrolysis furnace contains a variety of gaseous hydrocarbons (which, for example, are saturated, monounsaturated, and polyunsaturated, and may be aliphatic and/or aromatic), and contain large amounts of Of molecular hydrogen. The cracked products are then further processed, for example, in an olefin production unit to produce the various independent high-purity streams mentioned above as the product of the unit, namely, hydrogen, light olefins, ethylene, propylene and butenes, and aromatics, among other products. Such as pyrolysis gasoline.

Because the worlds demand for light olefins is increasing, and useful crude oil resources are consumed, it is necessary to use heavy crude oil (that is, those with a higher proportion of residual oil), which requires increased capital investment to process and process refining By-products and purchase higher-grade raw materials. It is very desirable to have a method that can more effectively utilize lower cost, heavy crude oil and produce a better product mixture of light olefins.

It has been proposed to improve the grade of certain crude oil fillings by first hydrotreating the feedstock before steam cracking. For example, US Patent Nos. 3,855,113 and 6,190,533 relate to a method that includes passing the feedstock through a hydrotreating zone and then through a steam cracking zone. However, there is no case where whole crude oil or fractions containing residual oil are directly transported to the hydroprocessing area. See also GB2071133 and Erdoel & Kohle, Erdgas, Petrochemie (1981), 34 (1), 443-6.

Conventional residual oil hydrotreating or "residue hydrorefining" is a known method to improve the quality of a part of crude oil containing residual oil. Hydrogenated liquid and vapor products (but not residual oil products) obtained from residual oil hydrorefining are usually stuffed into more valuable streams, such as fuel oil,

200680038858.0 No. Diesel, heating oil, jet fuel (jet), kerosene, gasoline, LPG and flue gas. All these materials themselves can be used as fuels and/or as intermediates for the production of petrochemical products, for example. For example, fuel oil can also be cracked to form lower boiling point fuels such as gasoline, LPG and fuel gas and/or petrochemical products ethylene, propylene and butanes. Residual oil fillings are usually low-value products. However, after the hydroprocessing and before or during the further steaming of the residual oil stream, the crude oil filling containing the residual oil may undergo conversion, deasphalting or other treatments.

US 3,898,299 discloses a method for removing residual oil content and producing alkene from non-residual oil and low boiling point compounds. The atmospheric residual oil obtained from the steaming hall is subjected to hydrotreating and the liquid hydrotreating effluent is directly fed to the pyrolysis zone in the presence of steam, where the steamed fillings are kept in thermal cracking conditions. Before the lower pyrolysis zone, unvaporized raw materials are removed as residual anchors in the separation zone". However, the 299 reference only teaches conventional hydroprocessing and thermal steam cracking of the top stream without residual oil, and does not properly propose or teach how to use the residual oil-containing effluent from the residual oil hydroprocessing unit as steam cracking. The raw material of the device. The '299 patent generally requires the separation and removal of the 650°F+ (343°C) boiling point from the treated hydrotreater effluent before steam cracking. Only the stuffing is processed into the stuffing. Those skilled in the art are well aware of the practical difficulties of steam cracking raw materials containing residual oil, including equipment fouling of the ordinary equipment of the '299 patent. Residual oil hydroprocessing is a known method for upgrading residual oil into fuels such as fuel oil, diesel, heating oil, jet fuel, kerosene, gasoline, LPG, and fuel gas. These materials can be used as fuels and/or intermediates for the production of petrochemical products, for example.

Other patents related to the cracking of heavy feedstocks include Wernicke's US Patent No. 4,257,871; Soonawala's US Patent No. 4, 065, 379; Franck's US Patent No. 4, 180, 453; and Wernicke's US Patent No. 0.4, 210, 520. However, none of the above-mentioned patents fully teaches how to steam crack the residual oil-containing hydrocarbon stream to produce alkene.

In US4,257,871, vacuum residual oil is used to produce alkenes by the following method: firstly separate the bitumen contained therein, blend the resulting bitumen-poor stuffing with lighter stuffing, and then blend this The product undergoes conventional catalytic hydrogenation and then thermal cracking. See also US4, 297, 204_o

200680038858.0 The Japanese Kokai patent application Sho58[1983]-98387 relates to a method for preparing gas alkene and mononuclear arene, which is characterized by hydrogenating crude oil with hydrogen and a hydrogenation catalyst, followed by thermal cracking. In embodiments, the hydrogenated crude oil can be distilled or flashed to separate the various components, and the top stream can be fed to the thermal cracking process. See also Japanese Kokai patent application Sho58 [1983]-005393 and Japanese Kokai patent application Sho57 [1982]-212294.

US 6,303, 842 teaches a method for preparing alkene by subjecting a residual oil containing a short boiling range residual oil with a boiling point higher than 565°C to thermal steam cracking, wherein at least 3wt% of the short boiling range residual oil has a higher or Equal to the boiling point of 650°C. The raw materials are prepared by ordinary hydroprocessing. Other meaningful references include US Patent Nos. 3, 855, 113; 4, 057, 490; 4, 179, 355 and 6, 743, 961₀Other patents related to the cracking of heavy feedstocks include Wernicke's US Patent No. 4,257,871; Soonawala's US Patent No. 4,065,379; Franck's US Patent No. 4,180,453; and Wernicke's US Patent No. . 4, 210, 520.

WO2004/005431 discloses a method for steam cracking certain feedstocks containing residual oil, in which a large amount of unconverted liquid residual oil content is removed before steam cracking. The '5431 invention does not disclose or teach hydrogenation as a method for improving the quality of heavy, acidic crude oil and residual oil feedstocks (which include residual oil fillings) so that whole crude oil including residual oil fillings can be steam cracked and converted It is a petrochemical product. Heavy, acidic feedstocks do not contain high concentrations of linear alkane, and they are known to constitute the highest quality steam cracker feedstock. The atmospheric and vacuum residues of crude oil containing >2.0wt% sulfur almost always have a hydrogen content of <12.5wt%, and usually they have a hydrogen content of <11.0wt%. As we all know, ordinary residual oil hydroprocessing produces products that are very prone to fouling.

There is a need in the art for devices and methods for economically processing heavy residual oil-containing whole crude oil and their residual oil-containing rotten fillings to prepare alkene, aromatic hydrocarbons and other valuable petrochemical products. All the prior art prior to the present invention has deficiencies, shortcomings or undesirable aspects.

SUMMARY OF THE INVENTION The inventors have surprisingly discovered that by integrating at least one hydrogenation step, at least one visbreaking step, and at least one thermal cracking step, it is possible to use a residual oil hydrotreatment with increased stringency and thermal integration with a steam cracker to prepare Useful products such as alkene and/or aromatic

200680038858.0 The first compound.

The present invention provides a method by which a hydroprocessing effluent containing residual oil filling can be used as a steam cracker raw material. The inventor also discovered that crude oil or its residual oil-containing components can be hydrotreated to be used as a raw material for a steam cracker. The hydrotreated residual oil-containing feedstock can be steam cracked to produce useful products such as olefin and/or aromatic compounds. The present invention relates to a method for integrating the hydrogenation and steam cracking of residual oil-containing materials to obtain alkene products.

One embodiment of the present invention is a method for preparing alkene from a raw material containing crude oil or crude oil fraction containing residual oil. The method includes a hydrotreating step, a visbreaking step, and a thermal cracking step. The method and device are capable of removing only the heaviest and least desirable residual oil components of the feed stream, and basically only the vaporized components (which include the vaporized components obtained from the residual oil) are transported to the steam crackerofradiant section.

In a preferred embodiment of any of the above methods, there is a visbreaking step before the steam cracking step and/or there is a vapor-liquid separation device integrated with the pyrolysis furnace, such as a visbreaker. The visbreaking process can be carried out in an integrated vapor-liquid separation device, which eliminates the need for a separate ordinary visbreaking process or equipment.

Another preferred embodiment is a method that includes splitting a portion of the residual oil group in the hydrogenation step, obtaining the effluent from the residual oil hydroprocessing unit, visbreaking the effluent, and visbreaking the effluent from the visbreaking step. The top product is transported to the radiant section of the steam cracker. Here again, visbreaking can be carried out in an integrated vapor-liquid separation device or in a visbreaker separate from the steam cracker.

In a preferred embodiment, the method further includes an integrated sub-commissioning step, such as the use of a flash tank to remove asphaltenes from the feedstock and/or the remaining boiling point before transporting the feedstock to the radiant section of the steam cracker unit Fillings above 1050°F (approximately 566*), preferably only those with a boiling point higher than 1100°F (approximately 593°C). Surprisingly, this can make the fouling rate equal to or better than the fouling rate of the VGO steam cracker feedstock. Preferably, at least one flash tank or other flash equipment such as an in-line choke, or orifice is provided to reduce the pressure in the hydrotreater effluent and cause some liquid to be converted to vapor. Preferably, the flash equipment and the feed of the steam cracker pyrolysis unit

200680038858.0 No. integration. Integration refers to heat integration so that heat can be obtained from one or more steps of the process (for example, during hydrotreating, preheating in the convection section) and/or from the steam cracker for conversion, cracking, flashing and Separation process. In a preferred embodiment, the pressure of the effluent of the hydrotreater is flashed off or reduced, which is at least one time before or during the separation. Flashing also includes the possibility of introducing the effluent into a vacuum.

In another preferred embodiment, the present invention includes a method for preparing a residual oil-containing hydrocarbon feedstock for steam cracking. The method of the present invention in one aspect includes hydrotreating the feedstock to hydrogenate the feedstock, thereby improving the hydrogen saturation of the cracked effluent. The method of the present invention further includes thermally cracking the undesirable effluent by further processing the hydrotreater effluent containing residual oil in a visbreaker and in a vapor-liquid separator (for example, in a visbreaking separation process The one used) recovers the improved residual oil-containing vapor effluent obtained from the visbreaking process to improve the hydrogenated residual oil-containing hydrotreater effluent. The present invention includes further improvements by visbreaking and/or separating visbreaking treated materials in a visbreaker and/or vapor-liquid separator integrated with a steam cracker, more preferably with a convection section of the steam cracker The quality of raw materials.

In one of the various embodiments of the present invention, where the effluent is obtained from a residual oil hydroprocessing unit, the feed stream fed to the residual oil hydroprocessing unit includes crude oil without filling or residual oil-containing Crude oil filling. In another embodiment, the hydroprocessing is performed using at least one fixed bed hydrogenation reactor, boiling reactor or fluidized hydrogenation reactor before feeding to the pyrolysis unit.

In other embodiments, the feedstock to be hydrotreated includes one or more of recycled steam cracker tar, heavy crude oil, or topped crude oil, and the feedstock to be steam cracked includes a hydrotreated recycled steam cracker. Tar, heavy crude oil or topped crude oil. In another preferred embodiment, the hydrogen source for hydroprocessing is from remote methane.

Some preferred embodiments also include a combination of two or more of the above embodiments (including preferred embodiments). In yet another preferred embodiment, the raw material is desalted or undesalted whole crude oil, or the product of the tubular stuffing tank of an oil refinery, or a chemical intermediate stream containing asphaltenes or residual oil, such as atmospheric residual oil or vacuum residual oil. Oil, or steam cracked tar, uses a fixed-bed hydrogenation reactor or a boiling or fluidized hydrogenation reactor with integrated steam in the feed

200680038858.0 Hydrotreating is carried out before the pyrolysis unit of the first gas-liquid separation plant.

The present invention also relates to a system comprising a hydrotreating unit, a pyrolysis unit and at least one vapor-liquid separation device for visbreaking, wherein the vapor-liquid separation device is advantageously integrated with the pyrolysis unit, and also relates to a system comprising A method of feeding raw materials to obtain products containing light olefins (one or more C2-C6 olefins). In a preferred embodiment, the system further includes a steam reformer for converting methane to hydrogen to provide hydrogen to the hydrotreating unit. An object of the present invention is to supply residual oil as a preferred feedstock to olefin producers, so that low-quality crude oil feedstocks can be used. Another object of the present invention is to increase the hydrogen content of the steam cracker feedstock while minimizing the increase in the residual oil content of the feedstock.

These and other objectives, features and advantages will become clear with reference to the following detailed description, preferred embodiments, examples and appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS In all the drawings, reference numerals, labels or other signs indicating parts or process components are used to indicate the same parts or components.

Figures 1-6 are process flow diagrams illustrating certain exemplary embodiments of the present invention.

DETAILED DESCRIPTION OF THE INVENTION In one embodiment, the residual oil-containing, initial thermal cracking effluent from a hydrotreater, preferably a residual oil hydrotreater (which includes those residual oil fillings with a boiling point below 1050 (approximately 566°) And preferably those with a boiling point lower than U00°F (approximately 593*)) are further cracked sufficiently, for example in a visbreaker/separator, and used as a feedstock for a steam cracker or other pyrolysis unit . In the pyrolysis unit, the vaporized filling is converted into the desired product, which includes alkene. The terms pyrolysis unit and steam cracker have the same meaning here; all refer to devices commonly referred to as steam crackers, even if steam is optional.

According to the present invention, the crude oil containing residual oil or its filling is hydrotreated. Generally, the residual oil hydrotreating according to the present invention can be carried out at a temperature of at least 600°F (315°C), preferably at least 650°F (343°C), and more preferably at least 750°F (399°C). Preferably, the pressure is at least 1800 psig_oThe purpose is to initiate at least 650°F+ (343Γ+) residual oil in the hydrogenation step

200680038858.0 The first part of thermal cracking, such as initial thermal cracking. This processing of heavy crude oil or heavy residual oil fillings may generally require a temperature of at least 750°F (399C +) to initiate thermal cracking of the light residual oil fillings. Therefore, in some embodiments of the method of the present invention, the initial thermal cracking temperature of the hydrotreater unit is at least 750°F (399Ό), or at least 780°F (451Ό), in other embodiments, the temperature must be At least 800°F (427°C)_cThe preferred processing temperature range can be 650°F (343°C) to 900°F (482°C) _oAccording to other alternative embodiments of the method of the present invention, the hydroprocessing can be performed at 500°F (260°C) to 900°C (482°C), preferably 650°F (343C) to 900°F (482Ό), More preferably 700°F (371°C) to 900°F (482°C), more preferably 750°F (399°C) to 900°F (482°C), still more preferably 750°F (399°C) ) To 800°F (427°C). In some embodiments, the preferred pressure is 500 to 10,000 psig, preferably 1000 to 4000 psig, still more preferably 1500 to 3000 psig_oThe selected temperature can be changed according to the formation and conditions of the suspected raw material. The preferred liquid hourly space velocity can be from 0.1 to 5, preferably from 0.25 to 1. The hydrogen supply rate (make-up and recycling hydrogen) of the hydroconversion zone can be 500-20,000 standard cubic feet per barrel of raw material, preferably 2,000-5,000 standard cubic feet per barrel. The hydroprocessing can be carried out using one zone or multiple hydroprocessing zones, for example, two or more hydroprocessing zones in parallel or in series. For example, in one embodiment, the first zone can include a first catalyst, which can be designed to accumulate most of the metals removed from the feedstock, and the second zone in series can include a second catalyst, which can be designed for Maximize the removal of heteroatoms and hydrogenation of aromatics. In another embodiment, the first catalyst can be designed to accumulate most of the metals removed from the feedstock, the second zone with the second catalyst can be designed to remove heteroatoms to the greatest extent, the second zone with the third catalyst The three-zone can be designed to increase the hydrogenation of aromatic bases. The first and second catalysts can be piped in reactors connected in series, or can be loaded in series in the same zone. The design details do not become a critical part of the invention, because it only concerns the residual oil hydrotreating unit.

The catalyst used in a typical industrial hydroconversion zone is composed of a material with hydrogenation-dehydrogenation activity and an amorphous carrier. Exemplary amorphous supports include alumina, silica-alumina, silica, aluminum oxide, or titanium dioxide. The hydrogenation-dehydrogenation component of the catalyst preferably includes at least one hydrogenation component selected from group VI metals and group VI metal compounds and at least one selected from group VIII

200680038858. 0 Group metal and group VIII metal compound in the hydrogenation component. Preferred combinations of hydrogenation components include sulfide and molybdenum, sulfide and molybdenum, diamond and copper, and sulfide and hook. The catalyst used in the present invention can also be composed of a material with hydrogenation-dehydrogenation activity that is not formulated with an amorphous carrier. Exemplary catalysts include Nebula.

According to the present invention, the residual oil hydrotreating can preferably be carried out at a temperature and pressure that are stricter than that of ordinary hydrotreating methods. In one embodiment, the hydrotreating can preferably be above 650°F (343°C) and at most a temperature at which significant cinnamon cracking occurs during the hydrogenation process, such as 750°F (399°C) to 800°F (427°C) )get on. This not only produces hydrogenated residual oil components, but also splits or decomposes most of the residual oil components into light fillings. The light fillings together with the injected steam contribute to the conversion, cracking and further vaporization and heat treatment of steam in the steam cracker, for example in the cracker pipes.

Residual oil hydroprocessing includes any method that essentially results in the hydrogenation of residual oil and/or residual oil-containing fillings, and includes, but is not limited to, commercially available residual oil hydroprocessing technologies. Examples of these commercially available methods are the Η-Oil method, the Chevron RDS, VRDS, OCR and LC-Fining methods, the HYVAHL method, and the ENI-Snamprogetti EST method. Suitable hydroprocessing methods may include, for example, a fixed bed catalyst system, a fluidized bed system, a fluidized bed system, and/or a combination thereof. The hydrotreating used herein also includes some mild cracking of the residual oil component of cassia raw material at 650°F+ (343°C+), preferably even from 650°F (343Ό) to U00°F (593°C) boiling point filling Some cracking of the filling from 650°F (3439) to 900°F (482°C) is more preferred.

The hydrogenation feedstock from the hydrotreater can then be further stuffed or vaporized, and then all fed to the steam cracker. Substantially complete vaporization can occur in the steam-steam cracker system. The combination of separator, flash separator and/or separation tank can be provided between hydrogenation and cracking as required. In a preferred embodiment, the separation process can be integrated with the heating and cracking process, for example with a steam cracker. For example, a vapor-liquid separator or separation process can be provided in the convection section of the steam cracker or between the convection section and the radiant section of the cracker.

The residual oil hydrotreating preferably includes increasing the hydrogen content of the whole crude oil or the residual oil-containing crude oil fillings by at least 1 wt%, preferably an increase of 1.5 wt%, and most preferably to achieve near saturation or complete saturation of the feed stream from the hydrotreater . In some embodiments, it may be preferred that the hydrogenation site

200680038858.0 The effluent of the first processor has a hydrogen content exceeding 12.5% by weight, more preferably exceeding 13% by weight. Increasing the hydrogen content of whole crude oil, crude oil, or other raw materials can be used to make their hydrogenated products suitable for feeding to pyrolysis units for cracking, thereby producing more valuable end products, such as olefins. As a result, lower-cost steam cracker feedstocks can be used for the production of olefins. Suitable lower value feedstocks may generally include heavy crude oil, those with high concentration of residual oil, high sulfur, high TAN, high aromatics, and/or low hydrogen content. The hydrogenation of crude oil or crude oil fillings and the removal of contaminants can facilitate the feeding of this effluent to the heaviest components of the feed stream such as asphaltenes and steam crackers at 1100°F+ (593Ό+) System or device. Residual effluent (which includes vaporized residual oil fillings, such as cracked and vaporized 650°F (343°C), up to 1050°F+ (565°C), or even up to 1100°F+ (593°C+) filling (Up to and including some 1400 tap (760°C) stuffing and vaporized low-boiling stuffing) are fed to the radiant section of the steam cracker for rigorous cracking and production of valuable petrochemical products, such as alkene. Hope some fouling, and did not produce undesirable tar and coke.

Surprisingly, this method can be carried out without causing uncontrolled fouling of equipment or undesirably producing high yields of tar and residual oil-containing by-products. Also, surprisingly, fully hydrogenated crude oil can be substantially completely vaporized in a steam cracker and result in an increased yield of petrochemical products. Conversion and vaporization can also be aided by steam-assisted flash vaporization. In addition, strict hydrogenation can also greatly reduce the production of steam cracker tar.

In a preferred embodiment, the hydrotreater effluent selected for steam cracking includes larger fractions with boiling points ranging from 700°F (37°C) to 900°F (482C). In another preferred embodiment, if the hydrotreater effluent contains residual oil, it can be treated first to remove a portion of the residual oil, such as asphaltenes, and then the treated and hydrogenated residual oil-containing material is fed to the heat The convection section or radiant section of the decomposition unit (steam cracker). The preferred method for removing the undesirable residual oil fraction is discussed below.

Crude oil as used herein refers to the whole crude oil that flows from wellheads, production oilfield facilities, transportation facilities or other initial oilfield processing facilities, optionally including those that have passed through desalination, treatment steps and/or in order to be able to carry out ordinary steaming in the refinery. Crude oil that requires other steps to be processed. The crude oil used herein is assumed to contain residual oil, unless otherwise specified.

Crude oil fillings are usually obtained from a tube-type filling kettle in an oil refinery. Although the tube steaming pavilion of the oil refinery

200680038858.0 Any crude oil filling obtained from the first tank can be used in the present invention, but the significant advantage provided by the present invention is that the crude oil or crude oil filling still containing all or part of the initial residual oil in the whole crude oil obtained from the wellhead can be used Hydrotreating and subsequent use as a feedstock for steam crackers. In one embodiment, the crude oil or other feedstock fed to the hydroprocessing unit may include at least 1 wt% residual oil, preferably at least 5 wt% residual oil, more preferably at least 10 wt% residual oil, and still more preferably at least 20 wt% residual oil.

Residual oil as used herein refers to a composite mixture of heavy petroleum compounds that is otherwise called residual oil or residue in the art. Atmospheric residual oil is the bottom product produced in an atmospheric steaming chamber when the end point of the heaviest steamed stuffing product is nominally 650°F (343°C), and is called 650°F+ (343 °C+) residual oil. Vacuum residual oil is the bottom product obtained from the tower under vacuum when the heaviest steamed stuffing product is nominally 1050°F (565°C), and is called 1050°F+ (565°C+) residual oil.

(The wording "nominal" here means that reasonable experts may have different opinions on the exact filling of these words, but it may not exceed +/-50 taps (or at most +/-100°F)_oThe 1050°F+ (565°C) part contains asphaltenes, which are traditionally regarded as disadvantages of steam crackers, leading to corrosion and fouling of the equipment. As used herein, the term "residual oil" refers to 650°F+ (343°C +) residual oil and 1050+ (565P+) residual oil, unless otherwise specified; note that 650°F+ (343°C +) residual oil Contains 1050+ (565°C+) residual oil. According to the present invention, at least a portion of the residual oil at 650°F+ (343°C) up to the boiling point of at least 1050°F+ (565Γ) is vaporized, for example, during (i) hydrotreating process, (ii) when combined with steam When combined, and/or (iii) between the hydrotreating unit and steam cracking, such as when the pressure is reduced or flash vented during the flash separation process.

Residual oil can also generally contain a high proportion of undesirable impurities such as sulfur and nitrogen and high molecular weight (C12+) naphthenic acids (determined by TAN according to ASTM D-664). Another advantage of the present invention is that raw materials containing large amounts of one or more of these impurities can be easily processed. As an example of a specific impurity, a large amount of sulfur may be present in the polycyclic heterocycle. By hydrotreating the residual oil containing these substances, not only the sulfur is removed as £S, but also the heterocyclic ring is opened to produce a large amount of monocyclic aromatic substances. They are usually valuable commodities in themselves and are also the preferred steam cracker raw materials. .

As used herein, the term "hydroprocessing" is defined as including processing in the presence of hydrogen

200680038858.0 The first hydrogen raw materials are those methods that hydrogenate or otherwise cause hydrogen to react with at least a portion of the raw materials. This includes, but is not limited to, a method that includes the step of heating the residual oil-containing raw material stream in the hydrotreating step in the presence of hydrogen, preferably also under pressure. Hydrotreating can also include, but is not limited to, hydrotreating, hydrotreating, hydrodesulfurization (HDS), hydrodenitrogenation (HDN), hydrodeoxygenation (HD0), hydrorefining, and hydrocracking. method.

The term "steam cracker" as used herein is also more commonly referred to as a pyrolysis unit or thermal decomposition furnace or pyrolysis furnace. Although steam is optional, it is usually added for one or more reasons, such as reducing the partial pressure of hydrogen, controlling residence time and/or minimizing coke formation. In a preferred embodiment, the steam may be superheated, for example in the convection section of a pyrolysis unit, and/or the steam may be acidic or treated process steam.

Usually, the raw materials are desalinated before being transported to the tube steamer. When the residual oil from the tubular filling kettle is to be hydrotreated, the crude oil feedstock to the refinery is often desalinated twice. Desalination usually removes metal salts such as NaCl_oHowever, desalted crude oil and crude oil fillings can still contain relatively high concentrations of one or more impurities such as naphthenic acid, sulfur and/or nitrogen. Another advantage of the present invention is that crude oil and crude oil fractions containing one or more of such naphthenic acid, sulfur and/or nitrogen impurities are easy to handle.

In a preferred embodiment, the raw material includes crude oil or atmospheric residual oil containing a larger amount of 1050+ (565°C +) residual oil, such as 10wt% or more residual oil, or 20wt% or more residual oil After the hydroprocessing, the raw material containing residual oil can be transported to the convection section of the pyrolysis unit, where it is heated. Then, the heated raw material can be transported to a visbreaker or other vapor-liquid separation device to remove the heaviest stuffing (for example, mainly asphaltene and 1050 + (565Π +)). Preferably, such a device is thermally integrated. Thermal integration provides additional efficiency for the visbreaker or separator.

In addition to the initial thermal cracking of the residual oil filling that occurs during hydroprocessing, most of the additional cracking, conversion, and flash separation occur in the visbreaker/separator. This further cracking and conversion is caused by applying an abnormally high separation/visbreaking temperature for an abnormally short contact time, thereby minimizing or controlling the coking to an acceptable level. When the feedstock containing residual oil is heated in the convection section to below 650°F (343°F) and even up to 700°F and the feedstock has a short residence time in the liquid-vapor separation unit, the heat

200680038858.0 The first cracking seldom occurs to not occur, usually only molecules vaporized under these conditions can be separated, for example, usually non-residual oil components. However, when the feedstock containing residual oil in the convection section according to the present invention is heated above 700°F (37°C), preferably above 750°F (399°C), and even more preferably above 780°F (415°C) And when there is a long residence time in the liquid-vapor separation equipment, a large amount of further thermal cracking occurs in the residual oil filling. In order to maximize the conversion of residual oil into low boiling point fillings, it is desirable to start cracking the residual oil fillings as early as possible in the process. According to the present invention, early thermal cracking is initiated in the hydrotreating unit, and then further thermal cracking is supported in the visbreaking/separation step, thus maximizing the portion of the vaporized feedstock. According to theory, the increased concentration of low boiling point fillings produced in the early stages of the process can help or promote the further fracture, cracking and/or conversion of residual oil into low boiling point fillings. This includes the conversion and cracking of residual oil fillings whose boiling point reaches and exceeds 1100 tap + (593°C), and even some of the residual oil fillings up to 1400°F (760 °C).

When the effluent of the hydroprocessing unit is heated (including reheating) to above 780°F (415°C), for example, 780°F (415°C) to 900°F (482Γ) and in the visbreaker or other When processed in the separator, thermal cracking of 650°F+ (343°C+) residual oil fillings still occurred, including those with a boiling point higher than 1050+ (565°C). At higher temperatures close to 900°F, the residence time can be shortened to a contact time that is not usually shorter than that of prior art hydrotreating or residual oil hydrofinishing.

Surprisingly, this occurs in unconverted 1050°F+ (565°C) residual oil without the formation of large amounts of coke, scale or solids. This type of thermal cracking and vapor-liquid separation process can be described as "visbreaking". Preferably, separation and heating are chelation methods. The term "integration" as used herein refers to "thermal integration" in that the vapor-liquid separation equipment or visbreaker is connected to the steam cracker through a pipeline, and is adjacent to or relatively close to the steam cracker, so that the raw materials can be It is heated in the convection section of the cracker, fed to the visbreaker, and then the top product of the visbreaker is fed back to the cracker, which has minimal heat loss and preferably does not need to separate the heating related to the visbreaking process .

Vapor-liquid separation equipment is also called "visbreaker", "separation tank", "separation tank" and "vapor-liquid separator". These terms can be used interchangeably. Also mentioned in this article is the "visbreaker", which is used as a vapor-liquid separation equipment. The distinguishing feature is that it is usually used in

200680038858.0 The operation at a higher temperature than some other separators is also conducive to further thermal fracture and cracking of the raw materials. The terms "flash tank", "flash tank", "visbreaker", "vapor-liquid separator" and "flash separator" are also well-known terms that generally have similar meanings, and can be used basically interchangeably here. . For example, the separation can also be referred to as a visbreaker, or vapor - liquid separator. The term "flashing" generally refers to a phase change from liquid to vapor when at least a part of the material in the container or stream enters by reducing pressure and/or increasing temperature. Therefore, "flash separation" can occur in the "flash tank" due to the inlet of the flash tank or the reduced pressure in the flash tank.

In a more preferred embodiment, the material is treated by visbreaking or mild thermal cracking to increase the vapor phase ratio by sacrificing bottom products. In some separation methods, such as high-pressure separators and/or flash separators, the raw materials can also be separated into bottom fillings, which are basically liquid fillings, and top fillings, which are basically vapor phases. . The bottom filling or liquid phase may include residual oil filling. The steam filling may also contain components derived from the residual oil filling. Preferably, the bottom filling and the steam filling effluent each contain a component derived from the residual oil filling, although the composition of the residual oil filling of the bottom effluent is different from the steam effluent. Thus, each of the steam stream and the bottoms stream can be steam cracked.

Visbreaking is a well-known, non-catalytic, mild thermal cracking method that uses heat to convert or crack heavy crude oil and residual oil into lighter components, and sometimes more valuable products, such as naphthenic oil. Filling and tar, but the heat will not cause carbonization. The raw material of cinnamon can be heated to the desired temperature under the desired pressure, for example in a furnace or a cracking reaction vessel. The method used may be, for example, a coil type, which is used for high temperature-short residence time, or a cracking reaction method, which is used for low temperature-short residence time processing, to obtain the desired fractured product mixture as required. The raw material stream can be thermally cracked to reduce the viscosity and chain length of the crumb molecules by cracking the molecules in the liquid phase. See, for example, Hydrocarbon Processing, September 1978, page 106. Viscosity reduction occurs when the heavy crumb or residual oil is thermally cracked at high temperature, usually 700°F (371°C) to 900°F (371°C to 482°C) for a few minutes before quenching to stop the reaction. Cracking. Some residual oil molecules crack or break, producing components that can be removed by standard atmospheric pressure and vacuum steaming. The conversion rate of residual oil in the visbreaker increases with the increase of temperature and residence time. High-strength visbreaking maximizes the conversion rate of 1050 tap + residual oil, through

200680038858.0 First, cracking of the visbreaker feedstock at a temperature higher than 840°F (450°C) can be completed for the longest possible reasonable time without the formation of large amounts of coke or carbonization.

One of the key aspects of the present invention is surprisingly using crude oil streams or fractions containing residual oils that are first strictly hydrotreated, such as crude oils that are highly hydrogen-saturated and most of the residual oils have been cracked, and those that have not been hydrotreated. Compared with heavy crude oil, a higher conversion rate than previously known visbreaking can be obtained. The improved visbreaking method and characteristics of the present invention are believed to be attributable to the high hydrogen content of the residual oil portion of the hydrotreater effluent and the increase in light fillings due to the initial cracking performed in the hydrogenation process .

In a preferred embodiment of the present invention, particularly severe visbreaking is caused, for example, visbreaking at temperatures exceeding 800°F (427) takes place in a vapor-liquid separation plant (visbreaker), preferably The equipment is integrated with the steam cracker (heat integration) as described above. The integrated vapor-liquid separation equipment can discharge the stream every two weeks to remove coke. This enables the separation plant to operate at significantly higher coke yields than a typical visbreaker, which may need to run for several months between shutdowns to remove coke, at least in part due to such system desorption. The complexity and time required for coke. The vapor top product of the visbreaking (which includes fractions from cracked residual oil) can then be fed to a steam cracker for further cracking into other products including light olefin streams.

Although light visbroken residual oil molecules (especially residual oil materials with a boiling point below 750°F (<400°C)) are vaporized without additional treatment, steam stripping is for heavy visbroken molecules (for example, their boiling point exceeds 750). That is (>400°C) vaporization may be necessary and helpful. The visbreaking reaction is fast enough so that purge steam and/or light rot can be added to the vapor-liquid separation device to strip the visbroken molecules. This increases the rate of vaporization in vapor-liquid separation equipment. Heating can also be used to increase the conversion rate of residual oil.

Viscosity can be controlled by changing the residence time of the liquid phase in the vapor-liquid separation equipment. In a preferred embodiment, the liquid phase level can be raised to substantially fill the headspace of the vapor-liquid separation device, thereby increasing the residence time of residual oil molecules to a level sufficient to affect at least partial visbreaking. Preferably, the visbreaker is at least half (50%) full of liquid, more preferably at least 75% full of liquid, and in certain embodiments, most preferably at least 90% full of liquid, based on the total volume of the container. Heating can also speed up the liquid phase

In the 200680038858.0 visbreaking process, the liquid residue is collected as a bottom stream in the lower part of the vapor-liquid separation equipment. In one embodiment of the present invention, the heater in the lower section of the vapor-liquid separation plant is used in conjunction with the convection section of the steam cracking furnace to provide additional heat if necessary. The additional heat can help keep the residual oil hot enough to continue the reaction and achieve significant visbreaking conversion of the residual oil from 750°F (399°C) to 1050°F (565°C).

Preferred vapor-liquid separation equipment or flash tanks and their integration with pyrolysis units were previously described in US Patent Application Publication Nos. 2004/0004022, 20040004027 and 2004/0004028, and the most recent US application filed on February 28, 2005 Serial number 11/068, 615, 10/851,486 filed on May 21, 2004, 10/851, 546 filed on May 21, 2004, 10/851, 878, filed on May 21, 2004 10/851, 494 filed on May 21, 10/851, 487 filed on May 21, 2004, 10/851, 434 filed on May 21, 2004, 10/851 filed on May 21, 2004 , 495, 10/851, 730 filed on May 21, 2004, 10/851, 500 filed on May 21, 2004, 11/134, 148 filed on May 20, 2005, October 28, 2004 10/975, 703 filed on July 14, 2004, 10/891, 795 filed on July 14, 2004, 10/891 filed on July 14, 2004, 981, 10/893, 716 filed on July 16, 2004, 11/009, 661 filed on December 10, 2004, 11/177, 076 filed on July 8, 2005; and September 20, 2005 It is described in 11/231, 490 filed on the same day. Another preferred device effectively used as the vapor-liquid separation device of the present invention is described in US Patent No. 6,632,351 as a "vapor/liquid separator", such as a visbreaker. Visbreaking is discussed in the aforementioned US Patent Nos. 10/851, 486; 11/134, 148; 11/009, 661.

In the method of the present invention, the visbreaker or vapor-liquid separation equipment is preferably at 700°F (371°C) to 900°F (482°C), more preferably 750°F (399^eC) to 900°F (482°C), still more preferably 780°F (415°C) to 900°F (482°C) and most preferably 800°F (427°) to 875°F (468°C) Next operation. Let the hydrotreated and partially cracked residual oil-containing material pass through a vapor-liquid separation drum while undergoing some pressure drop to obtain top vapor and bottom liquid, which can also be referred to as "flashing" (or other changes). Body, depending on the context).

200680038858.0 Another aspect of the present invention relates to the API gravity and sulfur content of the steam cracker feedstock. It is known that the quality of steam cracker feedstock improves as the API specific gravity of the feedstock increases and the sulfur content decreases. The inventors surprisingly discovered that the raw materials rich in sulfur and high-boiling polynuclear naphthenes, polynuclear aromatics, and partially saturated polynuclear aromatics (which often have lower API gravity), when first hydrotreated It can be the preferred feedstock for steam crackers.

It is also known in the art that the specific gravity and sulfur content of crude oil increase with increasing boiling point. For this reason, feedstocks rich in vacuum residues from crude oil with 15-40 API gravity and 1-4% sulfur may be some preferred feedstocks for the process of the present invention. Residual oil hydroprocessing removes sulfur throughout the boiling range of the feedstock. A large amount of hydrogen is consumed to remove heteroatoms from the vacuum residue and saturate the polynuclear aromatics contained in the vacuum residue. Residual oil hydroprocessing can be accompanied by catalytic cracking and thermal cracking of residual oil molecules into components that can be separated by standard branch methods. Initially, the inventors searched for residual oil hydrotreating conditions that would achieve higher than 50% 1050°F+ conversion and higher than 90% desulfurization. The inventor surprisingly invented a method in which the 1050+ conversion in the residual oil hydrorefiner (residual oil hydrotreater) is unnecessary, because this function can be passed in a separate step This is achieved by visbreaking the effluent of the residual oil hydrofiner.

Residual oil hydroprocessing is used in other refining methods to pretreat atmospheric residual oil (which contains 25-35wt% vacuum residual oil) in industry for use as a raw material for FCC units. In this method, the coke yield of the hydrotreated residual oil is usually 5-8wt%. This means that 92-95% of the residual oil feedstock fed to the integrated residual oil hydrorefiner and FCC unit is converted into liquid and gaseous products, and only 5-8wt% is lost as low-value coke.

The inventors surprisingly found that by integrating residual oil hydrotreatment, visbreaking and steam cracking to produce olefins, similar results can be obtained. In the method of the present invention, the hydrotreated residual oil is visbroken, and the vaporized top product from the visbreaker is steam cracked. The inventor surprisingly found that this method produced 6-9wt% visbreaker bottom product (similar to the coke produced in FCC but higher value) and 91-94wt% steam cracker product.

In order to make full use of the visbreaking ability of the method of the present invention, the preferred feedstock in the embodiment may contain 20-50wt% vacuum residual oil, and some feedstocks may even be whole crude oil. Residual oil hydroprocessing consumes a lot of hydrogen. The inventor noticed that hydrogen will be introduced into the vacuum residue

200680038858.0 In the first material, the hydroprocessing effluent material that can only be used as fuel oil is produced, and its value is lower than the value of the required chemicals (such as olefins). As mentioned above, one purpose of the method of the present invention is to increase the hydrogen content of the steam cracker feedstock while minimizing the increase in the hydrogen content of the remaining residual oil, which is usually sold as low-value fuel oil. The integration of rigorous hydroprocessing and visbreaking has surprisingly achieved this goal. Visbreaking effectively removes side chains with high hydrogen content from the nucleus composed of polynuclear naphthene and aromatic stones. The fouling in the visbreaker is limited by limiting the temperature and controlling the residence time, thereby avoiding the over-formation of coke or fouling of equipment.

Crude oil or its fillings containing residual oil, especially atmospheric residual oil, vacuum residual oil, or any refinery or chemical intermediate stream containing residual oil or asphaltenes can also be the preferred raw material for the hydrotreating process of the present invention. When the feedstock contains more than 0.1 wt% or preferably more than 5.0 wt% asphaltenes, it is advantageous to use vapor-liquid separation equipment to remove the asphaltenes before entering the radiant section of the pyrolysis unit. Preferably, as described above, the vapor-liquid separation device (visbreaker) can be advantageously thermally integrated with the pyrolysis unit, so that the feedstock is preheated in the convection section of the pyrolysis unit before entering the vapor-liquid separation device. Therefore, the term "integrated vapor-liquid separation device" is as used herein. As an alternative, the vapor-liquid separation equipment can be basically not thermally integrated with the cracker, so that the visbreaker has its own independent or supplementary heat source, so that the asphaltenes and any unsaturated or uncracked residual oil enter the pyrolysis unit in the feedstock. The radiant section was removed before. Both integrated and non-integrated configurations are within the scope of the present invention.

Preferred feedstocks may include cassia feedstock streams with a high concentration of tar and crude oil fillings such as topped crude oil ("topped crude oil" is approximately 500-600°F (260-315°C) fillings and higher fillings) . Generally, topping crude oil is used synonymously with atmospheric residual oil. Then, any crude oil or crude oil containing residual oil fractions can be advantageously processed according to the method of the present invention to obtain chemical products (light olefin and/or monocyclic aromatic stone), regardless of the residual oil content therein.

The following examples are used to illustrate but not limit the present invention. Many modifications and variations are possible, and it should be understood that within the scope of the appended claims, the implementation of the present invention may be different from what is specifically described herein.

In the following figures, "HDP" is a hydrotreating unit, "HPS" is a high-pressure separation device (for example, a tank with level control that separates gas and liquid under pressure), and "steam

200680038858.0 "The first cracker" is a pyrolysis unit, and the "steam cracker product recovery" is a system that includes one or usually several separation steps, such as steam towers. All of these devices or systems can be basically ordinary devices when viewed individually. And each is known in the art.

1 is a process flow diagram illustrating an embodiment of the present invention, in which the raw material 8 containing residual oil is hydrotreated in the hydroprocessing unit 10, and then sent to the steam cracker 20 to obtain multiple Products 41-44, which include ene base 42. The design details of the steam cracker 20 itself are not the subject of the present invention. Processing conditions can usually be easily determined by those skilled in the art. Unconventional steam cracking designs known in the art, such as furnaces heated by directly mixing superheated solids or gases with liquid feedstock containing residual oil, are also considered by the inventors for the invention described herein.

An embodiment of the method of the present invention for preparing a residual oil-containing feedstock for steam cracking involves heating the feedstock at temperatures above 700°F (371°C), preferably above 750°F (399°C), and more preferably above 780°F (399°C). Pharynx (415°C) is hydrotreated and the raw materials are strictly hydrotreated. The method also includes further improving the hydrotreater effluent by maintaining, heating, and further converting the hydrotreater effluent in a visbreaker-type vapor-liquid separator. Preferably, the visbreaker is thermally integrated with the steam cracker. In the heat integration method shown in FIG. 1, the atmospheric residual oil 8 is delivered to an ordinary hydrotreating processor (HDP) 10, such as a fixed bed hydrotreating processor. Many HDP units are commercially available, especially depending on the catalyst and configuration, such as from ExxonMobil. The design details of the HDP itself are not the subject of the present invention. The processing conditions of HDP are usually easily determined by those skilled in the art. The recovery of petrochemical products (light olefins and aromatics) is largely affected by the processing conditions selected in the HDP 10, the visbreaker-type vapor-liquid separator 30, and the steam cracker 20.

The hydrogenation feedstock 14 of the HDP unit is then sent to one or more separation devices (not shown) to recover hydrogen, lower the pressure and lower the temperature. A stream including hydrogen and light carbon products such as C2 and below can be recycled 12, and a hydrogenated effluent stream 14 containing products with a C2 boiling range (C2+) and higher (eg up to 1500°F) is recovered for further processing. Note that in many cases, the recycle stream 12 may contain ILS, which is preferably removed before entering the HDP unit 10, such as through membranes, absorbents, and the like. The bottom stream of HPS (not shown) can be divided into two or more streams. In addition to the method used in the present invention, the bottom

200680038858.0 The second stream (not shown) can be recycled to the residual oil hydrotreating unit 10, or further processed by conventional filling and refining.

In the case where the feedstock 14 still contains asphaltenes, they can advantageously be removed before entering the radiant section 24 of the steam cracker 20. The above and the following examples more fully discuss examples of methods for removing asphaltenes. Although not shown in detail in Figure 1, the hydrogenated C2+ stream 14 can be preheated in the convection section 22 of the steam cracker 20 before entering the vapor-liquid separation device 30, which contains the asphaltenes (marked Weigh) 1050°F + residual oil can be removed from vapor-liquid separation device 30 as bottom product 32. The vapor 34 returns to the convection section 22, preferably without cooling or condensation. The device schematically referred to as "S/C furnace" 20 in FIG. 1 is a common example of a steam cracking furnace, and its details are not the subject of the present invention. In addition to the integration of the vapor-liquid separation device 30, it has been described elsewhere in this document. It is described in the references discussed. The separation device 30 preferably functions as a visbreaker in that the device 30 separates, temporarily maintains and further heats the stream previously heated in the hydrotreater. As a result, initial cracking is caused in the hydrotreater, producing some lightweight components, and then causing subsequent cracking in the visbreaker. Through the light fillings produced in the hydrotreater, additional light molecules produced by visbreaking, further injection into the visbreaker and/or steam injected before the visbreaker, and optionally by flash pressure Drop, you can achieve basic It is completely vaporized. The separator 30 is also preferably thermally chelated with the cracker 20 in that the separator is close enough to the steam cracker 20 so that the separator preferably does not require additional or separate heating to facilitate the separation of visbreakers in the separator 30 . Thus, the separator 30 can be integrated with the steam cracker 20". The pressure is preferably reduced to 50-100 psi before the separated stream is sent to the steam cracker. Although not shown in detail in FIG. 1, in a preferred embodiment The hydrogenated C2+ stream 14 is heated in the convection section 22 of the steam cracker 20 at a temperature sufficient to initiate thermal cracking of the hydrogenated residual oil before being transported to the vapor-liquid separation plant through the pipeline 33, which contains asphaltenes (nominal) 1050+ residual oil is removed as bottom product 32 from vapor-liquid separation device 30. Steam (not shown) can be added to the vapor-liquid separation device to increase the ratio of the raw material removed as vapor 34. Another aspect of the invention Yes, for a given treatment temperature (especially high boiling point residual oil), increase the liquid level in the visbreaker separator

200680038858.0 The first can increase the liquid residence time, thereby further improving the conversion rate of residual oil filling. The visbreaker includes a vapor-liquid separation vessel or device that separates liquid fillings from vapor fillings, wherein the separation vessel includes a liquid volume that preferably occupies at least 50% of the volume of the vessel. Preferably, the liquid level of the separation container is at least equal to or higher than 75% by volume of the container, still more preferably higher than 80% by volume, and most preferably higher than 90% of the container volume.

The vapor 34 (which includes residual oil molecules that have been thermally cracked (also known as destructive vapor)) can be returned to the convection section 22. In this way, the convection section 22 of the steam cracker 20 can convert 1050°F + vacuum residual oil into light molecules. Eventually, the output of fuel oil decreases and the output of petrochemical products (such as the required light olefins and monocyclic aromatics) increases. If the temperature is too high or the residence time of the feedstock is too long, the thermal visbreaker vapor-liquid separation device 30 can cause coke formation. If this happens, the method may undesirably fill the vapor-liquid separation device 30 with coke, which requires the method to be interrupted. In a preferred embodiment, the temperature and residence time in the vapor-liquid separation device 30 are controlled to allow only a small amount of coking. For example, the steam cracker may be shut down every 15-40 days to easily remove an acceptable amount of coke from the radiant section 24, pipes, and/or separator 30 of the furnace 20 if necessary. The method of the present invention can use known methods and facilities to remove coke from the pipes of the vapor-liquid separation device 30 and the convection section 22 and the radiant section 24 of the steam cracking furnace 20. Because of this synergistic effect between visbreaking and steam cracking, the method of the present invention can reduce the residual oil in the visbreaker feedstock at a higher stringency than the ordinary visbreaker. The conventional visbreaker is designed It runs for several months before decoking is required.

The device schematically represented as "S/C furnace" 20 in FIG. 1 is a common example of a steam cracking furnace. Except for the integration of vapor-liquid separation equipment (not shown in FIG. 1), its details are not the subject of the present invention. And it has been described in references mentioned elsewhere in this article.

In another embodiment, all or any fillings of the hydrotreater effluent 14 containing 105QOF+ (565°C+) residual oil can be heated in the steam cracker 20 or by a separate heat source enough to initiate thermal cracking, but The temperature will not cause significant coking. The cracked stream can be kept at this temperature for a long enough time to obtain a conversion rate of 1050% + residual oil from 5wt% (low stringency) to 60wt% (high stringency) (ie, the material changes from 1050°F

200680038858.0 (565°C) The high boiling point residue of the residue oil is converted into low boiling point materials) but is short enough not to cause significant coking. The optimal temperature and time ("time at a certain temperature") for each specific raw material are different and can be determined by those skilled in the art through routine experiments. The time at a certain temperature is selectively terminated by quenching the hot bottom material to avoid fouling or coking. Based on the present disclosure, those skilled in the art generally consider this to be visbreaking. In the visbreaking vapor-liquid separation step, where (nominal) unbroken 1050°F+ residual oil and/or asphaltenes are removed as bottom products from the vapor-liquid separation equipment, and all or part of the visbreaker The vapor effluent 34 is sent to the steam cracker 20 before entering the radiant section 24, preferably to the convection section 22₀The separated steam is further processed and cracked in the radiant section 24 to obtain a steam cracker effluent 26 containing the desired light olefins 42.

An important advantage provided by the present invention is the high stringency hydrotreating and visbreaking of the effluent 14 of the hydrotreater, whether in a visbreaker equipped before the steam cracker and having an additional or separate heat source, or The visbreaker integrated with the steam cracker can achieve high conversion rates, such as hydrogen-rich 750°F+ (399°C+) residual oil and even 1050°F+ (565°C+) most of the material at least 50wt%, or even higher than 50wt%, for example up to 55wt% and even up to 60wt%_oThis provides a steam cracker feedstock 34 (or feedstock to the radiant section 24, if the visbreaker is integrated with the convection section 22 of the steam cracker) with more than 13wt% hydrogen. The bottom product 32 of the visbreaking plant 30 may include less than 11.5 wt% hydrogen in certain embodiments, and may be used as fuel oil and/or recycled to the hydrotreater, or fed to another processing unit such as catalytic Conversion system.

In the embodiment schematically illustrated in FIG. 6, the method of the present invention integrates the steps of residual oil hydrotreating 10, hydrotreated residual oil visbreaking 30 and steam cracking 20. A conventional visbreaker can be operated to perform the operating parameters of the present invention, thereby separating the vapor and/or liquid that is emitted from the unconverted residual oil feedstock. The stuffing liquid and/or vapor obtained from the residual oil hydrotreater 10 and/or the visbreaker 30 are processed in the steam cracker 20 to produce petrochemical products. At least one obvious advantage of this embodiment is that there is no need to directly integrate the vapor-liquid separation equipment with the convection section of the steam cracker 20.

The product of the steam cracker 20 is transported to the product recovery section of the steam cracker (not shown in Figure 6)

200680038858. 0 first), where various products can be recovered by separation, usually by steaming stuffing. The "chemical" stream includes ethylene, propylene and butenes. Separation itself is a conventional technique and is not the subject of the present invention.

Certain variations are obvious to those skilled in the art. For example, one or more vapor-liquid separation devices can be exchanged with other separation devices such as membranes, and integration with a steam cracker, although a preferred embodiment, is optional. However, it is highly preferred to remove the asphaltenes before the radiant section of the pyrolysis unit (steam cracker). Membranes are particularly useful, for example, to separate polar substances from non-polar substances (for example, before HDP units).

In the embodiment shown in FIG. 6, the method of the present invention integrates the steps of residual oil hydrotreating 10, hydrotreated residual oil visbreaking 30, and steam cracking 20. A conventional visbreaker can be operated to reduce The vapor and/or liquid from the museum is separated from unconverted residual oil raw materials. The filling liquid and/or vapor obtained from the residual oil hydrotreater and/or visbreaker is processed in a conventional steam cracker to form petrochemical products. At least one important advantage of this embodiment is that there is no need to directly integrate the vapor-liquid separation equipment with the convection section of the steam cracker.

Figure 2 is a process flow diagram illustrating an embodiment of the present invention, in which a raw material 8 containing residual oil is subjected to a hydrotreating 10 and then sent 14 to a steam cracker 20 to obtain various products including alkene.

In the embodiment of the method shown in Figure 2, the feedstock 8 (which in the preferred embodiment is atmospheric residual oil) is sent to a conventional hydrotreating unit (HDP) 10, such as a fixed bed hydrotreating unit. Again, the design details of the HDP itself are not the subject of the present invention. Exemplary process conditions for HDP step 10 are provided in FIG. 2. However, as recognized by those skilled in the art, these conditions can be changed and can be determined by routine experimentation. The actual conditions of one or more HDP units vary according to the specific feedstock and/or desired product integration with steam cracker conditions and visbreaker conditions, but a good starting point would be 2200±500psig (total pressure), 725±100 °F (measured at the reactor outlet), 3000 ± 200 SCFB hydrogen treated at 0.1-0. 3WHSV.

The hydrotreating feedstock 14 is sent to the high-pressure separator 15 operating under the conditions specified in, for example, FIG. 2. The conditions can also be changed, and those skilled in the art through routine experiments

200680038858.0 No. determination depends on the operating conditions of the raw materials and other devices in the system shown. The top stream 16 passes through a heat exchanger 17 shown in a conventional manner with an arrow passing through a circle, and can have a boiling point of 650, for example. Jie or lower filling composition. The cooled top stream 18 can be transported to the second HPS19 shown in Figure 2, and the stream is separated at 9 (PF) as shown to obtain materials containing C3 and higher carbon number materials (including naphtha and heavy The bottom stream 21 (which can be sent to the steam cracker 20) and the top stream 23 containing hydrogen, methane, ethane and ILS, the top stream is recycled, preferably after the ILS is removed, for example, by membranes, absorbents, etc. .

In the exemplary embodiment shown and illustrated in FIG. 2, the bottom stream 35 obtained from the first HPS 15 may include materials with a boiling point above 650°. In some embodiments, the bottoms stream 35 can be recycled or mixed with the bottoms stream 21 of the second HPS 19, and then depressurized 55. In fact, usually a part (for example, 0-9Owt% or 40-60wt%) is recycled (not shown), and a part of 35 (for example, 10-100wt% or 40-60wt%) is mixed and depressurized. Mixing with the 90°F liquid cools the liquid 35 from the first HPS15, reducing the amount of flashing that occurs under reduced pressure.

In another embodiment, the combined liquid effluent 14 from the residual oil hydrotreater 10 containing residual oil and, for example, vacuum gas oil (VGO) may be preheated in the convection section of the steam cracker 20, and then the The vapor from the integrated vapor-liquid separation equipment is returned to the convection section, and then introduced or transported to the radiant section of the steam cracker, where it is cracked. The bottom stream from the integrated vapor-liquid separation plant consisting of 1050°F+ (in the preferred embodiment) includes asphaltenes.

The product 26 of the steam cracker 20 can be transported to the product recovery section 40 of the steam cracker, where various products 41-44 can be recovered through separation, usually by steaming stuffing, as shown in FIG. 2. The "chemical" stream 42 includes, for example, ethylene, propylene, and butenes. Each steam cracker 20 can be integrated with its own product recovery unit 40, or a single product recovery unit 40 can process two steam cracker effluents 26, 38.

Certain variations will be apparent to those skilled in the art. For example, other separation equipment such as membranes or vacuum towers can be added. The membrane is particularly useful for separating polar and non-polar substances (for example, before the HDP unit) or separating aromatic and non-aromatic substances (for example, after the second HPS unit in FIG. 2 and before the steam cracker). , Transport the non-Fang Dou to

200680038858.0 No. steam cracker and recirculation of Fangrong to the hydroprocessing unit).

Figure 3 shows another preferred embodiment of the present invention. Fig. 3 is similar to Fig. 2, except that in Fig. 3, the tar 44 from the product recovery unit 40 heated to 100-200C to maintain fluidity, is now basically free of metals and contains very little sulfur, can be transported to the HDP 10. It is preferably diluted with one or more 650°F+ recycle streams 23 and/or feedstock 8, or a portion of one or both of these materials.

Figure 4 shows another embodiment of the present invention. Figure 4 is similar to Figure 3, except that the second HDP unit 70, the second heat exchanger 72 and the third HPS unit 74 are provided₀As shown in FIG. 4, the material 76 (for example, 400-650°F (204-343Γ) liquid) from the third HPS unit 74 is sent to the second HDP unit 70 as a raw material. The tar 44 is optionally recycled to the second HDP unit 70. Figure 4 further uses a vapor-liquid separation device 25 (flash in Figure 4) to separate the 900 tap-vapor 36 from the 900°F + residual oil 37. 900°F-Vapour 36 (mixed with steam 31) can be sent directly to the conventional steam cracker 20 without the need for integrated vapor-liquid separation equipment. The 900°F + residual oil 37 can be delivered to the steam cracker 50 including the integrated vapor-liquid separation unit 30 to be visbroken. The vapor-liquid separation device 30 can be operated under various conditions, which can be easily understood by those skilled in the art. In another variant (not shown), a part of the tar 44 may be mixed with the atmospheric residual oil 8 and a part with the bottom product 76 of the third HPS unit.

Based on the present disclosure, those of ordinary skill in the art will recognize that in any of the above-mentioned Figures 1-4, the visbreaker may be arranged before one or more steam crackers. If the visbreaking step precedes the pyrolysis step, according to the present invention, a vapor-liquid separation device integrated with the pyrolysis furnace will be optional. This can be explained with reference to the following embodiments and other drawings described below.

Referring to FIG. 5, visbreaking is completed in a vapor-liquid separation device 30 integrated with the steam cracker 20. In the example shown in Figure 5, the crude oil is steamed at 1 atmosphere pressure until the remaining oil reaches 600°F (approximately 315°C). Heavy oil (residual oil) is analyzed (see Table 1). 2WHSV, 695. Heavy oil (residual oil) is mixed with hydrogen and passed through a hydrotreating processor 10 at 0.2WHSV, 695. It is processed under total pressure of 2000psig. Analyze the hydrotreater effluent 14 (see Table 1). The liquid product 14 of the hydrotreater is then vacuum steamed (not shown in Figure 5) to

200680038858.0 The vacuum residual oil is separated. Steaming the stuffing obtains 82wt% stuffing extract (1050-) and 18wt% vacuum residual oil (1050+). The analysis results are provided in Table 1.

The result of visbreaking 30 of 18wt% vacuum residual oil can be estimated. Due to the high hydrogen content (12.5 wt%) of the feedstock 14, a high conversion rate in the visbreaker 30 is possible before a large amount of coke begins to form. Strict visbreaking produces a vacuum residue containing up to 10.8wt% hydrogen in a 40% yield and a top product with a hydrogen content of 13.5wt%H in a 60wt% yield. The calculated hydrogen (H) content of the top product of the visbreaker is close to the H content of the residual oil hydrorefining liquid from the museum. Therefore, it can be assumed that adding the top product of the visbreaker to the filled hydrotreating liquid will not significantly change the steam cracking yield. The 93 wt% filling material stream 34 from the residual oil hydroprocessing step can then be used as a steam cracker feedstock. Table 2 provides the yield of steam cracking, which is basically the same as the yield shown in FIG. 5. The experiments reported in these examples simulate industrial-scale operations, as shown in Figure 5 and described throughout.

Table 1

<td></td><td>Crude Oil Atmospheric Residual Oil</td><td>Hydrotreater effluent</td><td>1050-</td><td>1050+</td>

<td>API weight</td><td>17. 8</td><td>27. 0</td><td>30. 0</td><td>17. 5</td>

<td>Wt%H</td><td>11. 3</td><td>12. 9</td><td>13. 1</td><td>12. 5</td>

<td>Wt%S</td><td>4. 2</td><td>0. 15</td><td>0. 01</td><td>0. 3</td>

<td>Wt%C5-</td><td>0. 0</td><td>3. 0</td><td>5. 0</td><td>0. 0</td>

<td>Wt%C5-1050°F</td><td>64. 0</td><td>80. 0</td><td>95. 0</td><td>0. 0</td>

<td>Wt%1050+</td><td>36. 0</td><td>18. 0</td><td>0. 0</td><td>100. 0</td>

<td>Alkane</td><td>16. 0</td><td></td><td>27. 0</td><td></td>

<td>Naphthene</td><td>19. 0</td><td></td><td>39. 0</td><td></td>

<td>Single ring</td><td>8. 0</td><td></td><td>26. 0</td><td></td>

<td>Bicyclic Fangguai</td><td>15. 0</td><td></td><td>7. 0</td><td></td>

<td>Sanhuanfang</td><td>17. 0</td><td></td><td>2. 0</td><td></td>

<td>Sihuanfang</td><td>13. 0</td><td></td><td>0. 0</td><td></td>

200680038858.0 Table 2-Steam Cracking Yield: Hydrotreater 1050-Liquid

<td></td><td>Steam cracker yield, wt%</td>

<td>Fuel gas</td><td>10</td>

<td>Ethane/Propane</td><td>5</td>

<td>Ethylene</td><td>21</td>

<td>Acrylic</td><td>13</td>

<td>C4, s</td><td>10</td>

<td>BTX</td><td>9</td>

<td>Other SCN</td><td>11</td>

<td>Tar and gas oil</td><td>21</td>

The results in Table 1 indicate that the feedstock fed to the residual oil hydroprocessing step contains 36 wt% of materials with boiling points above 1050°F. The product of the hydrotreating step contains 18% by weight of materials boiling above 1050°F. Conventional hydroprocessing results in a 50% conversion rate of the vacuum residual oil filling of the raw material. This means that the hydrotreating and subsequent vacuum steaming of the stuffing resulted in a product with 18wt% vacuum residual oil and close to 80wt% liquid suitable for use as a steam cracker feedstock. 18wt% vacuum residual oil is mainly rich in hydrogen, but can only be sold as low-sulfur fuel oil unless it is further processed. It is hoped to reduce the yield of low-sulfur fuel oil and increase the yield of steam cracker feedstock. The visbreaking step converts approximately 60 wt% of 12.5 wt% H, 1050°F+ hydrotreater effluent into steam cracker feedstock. The unconverted 1050+ residual oil hydrofining effluent contains 10.8wt% H, which is similar to the H content (11. 3wt%) o The combination of residual oil hydrotreating and visbreaking results in an 80% total conversion rate for the vacuum residual oil portion of the feedstock fed to the hydrotreater. 7wt% low-sulfur fuel oil ("residual oil" in Figure 5) has a hydrogen content similar to that of the residual oil hydrotreater raw material, so there is almost no hydrogen consumption in the residual oil hydrotreater, and it is sold to consumers as fuel oil By. On the contrary, the hydrotreating of the residual oil of the feedstock enables the visbreaking to proceed at an unusually high conversion rate. Feeding the rigorously hydrotreated residual oil to the visbreaker is also believed to be an important advantage of the embodiments of the present invention not previously recognized in the art, because it is completely unclear why it can be used for visbreaking according to the present invention The raw material is the opposite of feeding the raw material to the coker or FCC unit in the prior art.

Residual oil hydrotreating using similar raw materials and conditions as those listed in the above table

200680038858.0 First pretreatment of residual oil used as feedstock for FCC unit. In the FCC unit, the residual oil from the hydrotreating process can be converted into liquid and gas products with a coke yield of 5-6 wt%. It is very surprising that residual oil hydrotreating and subsequent visbreaking and steam cracking have achieved similar total residual oil conversion rates for liquid and gas products. The by-product of residual oil hydroprocessing, visbreaking and steam cracking is low-sulfur fuel oil ("residual oil" in Figure 5), which has a significantly higher value than coke on FCC catalysts.

The two key parameters of the steam cracker feedstock are wt% hydrogen and wt% polynuclear aromatics. The ethylene yield can be closely related to wt% hydrogen, and the tar yield can be closely related to wt% polynuclear aromatic cinnamon. The product obtained by hydrotreating the residual oil of Fig. 6 has the typical hydrogen content of ordinary VGO used in the field of steam cracking, but has a lower concentration of polynuclear aromatics.

The result of a steam cracked feedstock with &gt;20wt% aromatic crumb is a tar yield of 10-20wt%. The method of the present invention provides an opportunity to eliminate or greatly reduce the tar as a product by recycling the tar to the hydrotreater. Tar hydrogenation and subsequent steam cracking can substantially completely convert tar into light products. This is an ideal of the method of the present invention, but not just a necessary aspect. The steam cracker tar is abnormally hydrotreated in advance. It is expected to have problems with fouling, incompatibility and low reactivity.

Although the above embodiments use atmospheric residual oil as a raw material to illustrate, any crude oil or its filling can benefit from the present invention. In a preferred embodiment, the feedstock is selected from heavy crude oil, vacuum residual oil, fuel oil, FCC circulating oil, coker gas oil, cracker tar, topped crude oil and any other residual oil-containing and/or high-concentration polycyclic aromatic oil. At least one of the raw materials of the strange substance. Mixtures of such raw materials, such as those provided by crude oil, are also preferred. Figures 1-6 only represent a few of the countless possible optimization options that involve minimizing the refinery's energy use and maximizing the effective use of hydrogen and nephron feedstock sources.

As a further non-limiting example illustrating yet another embodiment (which may be a more preferred embodiment), the hydrogen source used in the system (such as the HDP unit) may come from a source of methane, especially remote methane. The use of remote methane as a hydrogen source is described in US Patent No. 6,784,329.

Maximizing the value of remote methane resources is an old problem in industry. Although methane has high-quality value for the production of hydrogen, usually any chemical

200680038858.0 The first is economic. Hydrotreating the feedstock of the hydrotreating unit using methane or other sources of high capacity and/or underutilized capacity from remote areas may be beneficial to economically improve the production of valuable products from steam cracking. The term "remote" is not limited to distance, but is more broadly defined to include essentially any suitable source of methane and/or hydrogen, which may be less valuable options or less likely to be used in the method described.Yu said the method. In the method. This includes methane produced in large quantities throughout the world, which may be restricted, costly, or unsuitable in terms of market access or restricted use. This methane can be converted to hydrogen used in the process of the invention.

Crude oil usually contains a minimum of 10wt% hydrogen. Fully hydrogenated crude oil (where the crude oil essentially contains only alkanes and naphthenes, with a conversion rate of &gt;95 wt% of impurities containing sulfur, nitrogen and oxygen) can contain as much as 14-15 wt% hydrogen. This saturated cracker feedstock is a highly preferred feedstock in the present invention. The yield of petrochemical products of crude oil with 14.5wt% hydrogen can be significantly increased compared to crude oil with 10-11wt% hydrogen.

A convenient way to convert methane to hydrogen in remote locations is to use a steam reforming unit, which is available from many commercial sources. In steam reforming, light crumbs such as methane react with steam to form hydrogen and carbon monoxide. This reaction can be explained by the well-known syngas balance equation:

CH₄ + H₂0 "" 3H₂ + CO Generally, syngas is utilized, for example, by converting it to lower alkane with a Fischer-Tropsch catalyst, which can be fed to a naphtha cracker to produce ethylene. However, according to the present invention, hydrogen can be extracted from the product side of the equation and used to hydrogenate crude oil or its residual oil-containing fillings. Carbon monoxide can further react with steam in the water gas shift reaction to form additional hydrogen (and carbon dioxide). Other reactions can produce hydrogen from methane, for example methane reacts with oxygen to form hydrogen and carbon monoxide (partial oxidation).

The present invention therefore allows manufacturers to locate the HDP unit close to the methane source (for example, remote methane), hydrogenate feedstock containing residual oil (for example, from a wellhead located near remote methane or by transporting residual oil-containing materials to Remote methane location), and then ship the HDP unit's products to the steam cracker (or place the steam cracker at a remote source).

In addition to those noted above, the present invention provides many advantages. In the best practice

200680038858.0 In the first embodiment, the present invention provides one or more of the following advantages: (a) Use of the lowest cost raw materials (1050 scare of raw materials + high residual oil and/or polynuclear aromatics and/or high heteroatom content; use remote locationsofmethane); (b) When combining the conversion in the residual oil hydrofiner and the visbreaker, it has a high total conversion rate of 1050°F+; (c) Feedstock including hydrogen and steam cracker Low-cost integration of facilities, basically without transportation costs; (d) Single feed material simplifies pyrolysis unit design and/or maintenance; (e) Reduced residual oil/asphaltene/sulfur and nitrogen polynuclear molecules (" "Bottom material) treatment/disposal issues; (f) provides an alternative to the reforming of naphtha for the production of aromatic products.

Although the present invention has been generally described with reference to specific embodiments, in a preferred embodiment, the present invention relates to a method comprising the following steps: (i) acquisition under relatively strict conditions, such as preferably exceeding 700°F (371°C) , More preferably a feedstock containing the effluent from the residual oil hydrotreating unit processed at a temperature exceeding 750°F (399°C); (ii) separating the effluent in a separator (for example, visbreaking) into The top stream and the bottom stream, where the top stream includes steam; then (iii) the top stream of the visbreaker is transported to the radiant section of the steam cracker; (iv) the effluent containing olefin is obtained from the steam cracker.

This can be improved or enhanced by one or more of the following still more preferred embodiments: wherein step (iii) is characterized in that the top stream of the visbreaker is sent to the steam cracker as vapor without cooling or condensation; step (iii) ) Includes transporting the top stream of the visbreaker to the convection section of the steam cracker, and then to the radiant section of the steam cracker; step (ii) includes transporting the effluent to the convection section of the steam cracker, and then in the vapor liquid In the separation device, the effluent is visbroken; in step (ii), the visbreaker/vapor-liquid separation device is thermally integrated with the steam cracker; step (i) is further characterized by hydrogenating the raw material containing crude oil or crude oil content Processing to obtain hydrotreated crude oil or hydrotreated crude oil fillings, wherein the hydrotreated crude oil fillings include residual oil; step (i) is further characterized in that it will contain &gt;20wt% or &gt;25wt%, or&gt; 30wt% 1050°F+ residual oil and &gt;20wt% or &gt;25wt% or &gt;30wt% Fanggua and &lt;25wt% or &lt;20wt% or &lt;15wt% paraffinic crude oil or crude oil is hydrotreated to obtain Hydrotreated crude oil or hydrotreated crude oil fillings, in which the hydrotreated crude oil fillings include residual oil; visbreaking is carried out under suitable conditions (usually 700°F (371°C) to 900°F ( 482°C), or higher than 850°F in other embodiments

200680038858.0th

Ο450Ό) to 900°F (482°C), or within the preferred operating range of vapor-liquid separation equipment at 425-467°C, or within the range from any lower limit to any upper limit given in the bracket expression, for example 425-482C and 450-467 wool) to provide more than 5wt%, preferably 5-60wt%, more preferably 50-60wt%, still more preferably &gt;50wt% to 60wt%, still more preferably &gt;55wt% to 60wt% The conversion rate of the material&gt; 1050 tap + residual oil to &lt;1050°F + (in other words, the "time at a certain temperature" sufficient to provide the above conversion rate); including hydrotreating crude oil or hydrotreating The visbreaking step of the crude oil fillings and the subsequent separation step of obtaining the fillings containing residual oil and the fillings without residual oil, and then the step of steam cracking the fillings without residual oil into products containing olefinic cakes; The raw materials include crude oil or crude oil fillings containing at least one impurity, the impurities selected from: (a) based on the weight of the raw material, more than 1wt%, more preferably more than 3wt% of sulfur, (b) based on the weight of the raw material On a benchmark basis, more than 10wt%, preferably more than 2Owt%, more preferably more than 30wt% residual oil, (c) TAN measured by ASTM D-664 is&gt; 1.0, preferably&gt; 1.5, more preferably&gt; 2.0 , Still more preferably&gt;: 2. 5 mg KOH/g oil, more preferably&gt; 3.0 mg KOH/g naphthenic acid of the oil; step (i) saturate at least 20 wt%, preferably at least 40 wt% of the aromatic cinnamon material in the raw material; the product of step (ii) It further includes tar, which is recycled to the feed of step (i); the feed includes steam cracker tar.

Another preferred embodiment of the present invention relates to an integrated hydrotreating and steam cracker system for preparing alkene from crude oil containing residual oil and crude oil fractions, the system including at least one hydrotreating unit and at least one high-pressure separator At least one visbreaker, at least one steam cracker optionally having a vapor-liquid separation device integrated therewith, and at least one steam cracker product recovery device. This can be improved or enhanced by one or more of the following features: the system further includes a steam reformer arranged at the same location as the hydrotreating device, and configured to supply hydrogen to the hydrotreating device; further features of the system It consists of a visbreaker and at least one steam cracker optionally with integrated vapor-liquid separation equipment in the following order and in series; the system does not include an integrated vapor-liquid separation equipment; the system includes an integrated vapor- Liquid separation equipment; the visbreaker is integrated with the steam cracker between the convection section and the radiant section. Another preferred embodiment includes a method for preparing alkene from a raw material. The method includes feeding the raw material to a system with a hydrotreating unit and a steam cracker. The improvement includes directly feeding the residual oil-containing material to the system. plus

200680038858.0 Hydrotreating unit and the hydrotreating of residual oil-containing materials. In the visbreaker, the effluent of the hydrotreating unit is visbroken, and then the effluent of the steam cracker is used to obtain C2-C6 olefins and monomers. At least one of the aromatic cinnamon substance, which can be improved or enhanced by an embodiment in which substantially all the effluent from the visbreaker is supplied to the convection section of the steam cracker, where it is combined with The steam is mixed and then sent to the vapor-liquid separation equipment integrated with the steam cracker to provide a first stream consisting essentially of vapor materials and a second stream consisting essentially of non-vapor materials, and then in the steam cracker The radiant section cracks the vapor material and recovers the steam cracker effluent containing at least one of C2-C6 alkene and monocyclic aromatic substances. Yet another preferred embodiment of the present invention is a method comprising feeding a feed stream containing residual oil to a system according to any one of the system embodiments described in the present disclosure, preferably those of the preferred embodiment set forth in this paragraph In the system, at least one product selected from the group consisting of C2-C6 alkenes and monocyclic aromatic substances is obtained from the steam cracker product recovery device.

Some other preferred embodiments of the method of the present invention can be described as follows: (1) Obtain the effluent from the residual oil hydroprocessing unit, wherein the effluent contains 650°F+ (343°C+) residual oil; (ii) in the separation In the reactor, the effluent is separated into a top stream and a bottom stream; then (iii) the top stream is transported from the separator to the steam cracker; (iv) the top stream is steam cracked in the steam cracker and steam is obtained from the steam cracker Cracker products, which include olefins. Preferably, step (iii) is characterized by conveying the top stream as steam from the separator to the steam cracker. The separator may include at least one of a visbreaker, a flash tank, a high-pressure separator, and a vapor-liquid separator. It should be understood that it can be demonstrated that there are small differences between these devices, and these terms are often used interchangeably. The separation step may include visbreaking the effluent and separating the gas mixture from the liquid filling.

Preferably, the method further comprises the step of flashing the effluent by at least one pressure drop before steam cracking the effluent in the steam cracker, which pressure drop reduces the pressure of the effluent by a factor of the pressure of the effluent in the hydrocracking unit At least half. In fact, this pressure drop can basically be combined with the visbreaking operation to cause a portion of the liquid to flash into vapor in the visbreaker/separator. At least one pressure drop is generated substantially just before or within the separator. Preferably, the thermal cracking of the raw materials starts in the hydroprocessing unit, and the cracking starts in the

200680038858.0 continued in the visbreaker/separator. Surprisingly, rigorous hydrotreating combined with rigorous visbreaking is used to crack most of the 650°F+ (343Γ +) residual oil and even most of the 105()OF+ (565°C+) residual oil. . Thus, most of the bottom filling (by weight) obtained in the separation step includes residual oil with a boiling point of at least 900°F (482°C), preferably at least 1050°F+ (565°C+). In a preferred embodiment, the separation step includes separating the effluent in a vapor-liquid separation vessel such as a flash tank or a visbreaker, where the vessel is at least one of the following: (i) thermally integrated with a steam cracker, For example, by positioning and/or connecting pipes, a separate heat source is not required, and/or (ii) heating with a heat source other than the steam cracker.

In a preferred embodiment, the effluent in the separator/visbreaker is heated to a temperature of at least 750°F (399°C), more preferably to a temperature of at least 800°F, and still more preferably to a temperature of 850° F (454°C), and most preferably a temperature of 750°F (399°C) to 900°F (482°C). It is also preferred that the effluent from the separator/visbreaker remains in the separator for at least the shortest time determined, and not longer than the longest time determined. This is a conventional method of visbreaking and flash tank operations. It is necessary to quench the bottom liquid stream in order to stop the reaction, avoid scaling or coking, and at the same time allow sufficient reaction time to make most of the residual oil (including 1050 °F+ (565°C+) residual oil) is fully cracked into light components. The exact timing depends on the performance of the crude oil feedstock and the performance of the effluent in the separator.

Preferably, the method of the present invention includes the step of processing the residual oil-containing raw material in a hydroprocessing unit, wherein the processing includes the step of treating the raw material with hydrogen at 750°F (399°C) to 900°F (482 c) Combine at temperature. Preferably, the hydrogen comes from a remote source. The hydrogenation method can be carried out under a pressure of 1000-4000 psig, and the hydrogenation treatment saturates at least 20 wt%, preferably at least 40 wt% of the aromatic substances in the raw material. The preferred method also includes adding steam to at least one of the effluents of the hydrotreating unit and the separator. After cracking the steam filling in the steam cracker, the desired alkene and other products can be recovered by other known methods.

The meanings of the terms used herein adopt their ordinary meanings in the field; in particular, refer to Handbook of Petroleum Ref ining Processes, third edition, Robert A. Meyers, editor, McGraw-Hi 11 (2004) _oIn addition, all patents and patent applications, test procedures (such as ASTM methods), and other documents cited herein are incorporated by reference in their entirety to the extent that this disclosure is consistent with the present invention and all permissions permitted for this introduction.

200680038858.0 In addition, when the numerical lower limit and the numerical lower limit are listed in the text, the range from any lower limit to any upper limit is taken into account. It should also be noted that the trade names used in this article are represented by the'symbol or ® symbol, indicating that the name is protected by certain trademark rights, for example, they can be registered trademarks in many jurisdictions.

The invention has been described above with reference to many embodiments and specific examples. Based on the above detailed description, many variations are obvious to those skilled in the art. All these obvious variations are within the full scope of the appended claims.

200680038858. 0