Classifications

• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G9/00—Thermal non-catalytic cracking, in the absence of hydrogen, of hydrocarbon oils
  • C10G9/005—Coking (in order to produce liquid products mainly)
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G11/00—Catalytic cracking, in the absence of hydrogen, of hydrocarbon oils
  • C10G11/14—Catalytic cracking, in the absence of hydrogen, of hydrocarbon oils with preheated moving solid catalysts
  • C10G11/18—Catalytic cracking, in the absence of hydrogen, of hydrocarbon oils with preheated moving solid catalysts according to the "fluidised-bed" technique
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G51/00—Treatment of hydrocarbon oils, in the absence of hydrogen, by two or more cracking processes only
  • C10G51/02—Treatment of hydrocarbon oils, in the absence of hydrogen, by two or more cracking processes only plural serial stages only
  • C10G51/023—Treatment of hydrocarbon oils, in the absence of hydrogen, by two or more cracking processes only plural serial stages only only thermal cracking steps
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G51/00—Treatment of hydrocarbon oils, in the absence of hydrogen, by two or more cracking processes only
  • C10G51/02—Treatment of hydrocarbon oils, in the absence of hydrogen, by two or more cracking processes only plural serial stages only
  • C10G51/04—Treatment of hydrocarbon oils, in the absence of hydrogen, by two or more cracking processes only plural serial stages only including only thermal and catalytic cracking steps
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G9/00—Thermal non-catalytic cracking, in the absence of hydrogen, of hydrocarbon oils
  • C10G9/34—Thermal non-catalytic cracking, in the absence of hydrogen, of hydrocarbon oils by direct contact with inert preheated fluids, e.g. with molten metals or salts
  • C10G9/36—Thermal non-catalytic cracking, in the absence of hydrogen, of hydrocarbon oils by direct contact with inert preheated fluids, e.g. with molten metals or salts with heated gases or vapours
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G2300/00—Aspects relating to hydrocarbon processing covered by groups C10G1/00 - C10G99/00
  • C10G2300/40—Characteristics of the process deviating from typical ways of processing
  • C10G2300/4006—Temperature
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G2300/00—Aspects relating to hydrocarbon processing covered by groups C10G1/00 - C10G99/00
  • C10G2300/40—Characteristics of the process deviating from typical ways of processing
  • C10G2300/4081—Recycling aspects
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G2300/00—Aspects relating to hydrocarbon processing covered by groups C10G1/00 - C10G99/00
  • C10G2300/70—Catalyst aspects
  • C10G2300/708—Coking aspect, coke content and composition of deposits
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G2300/00—Aspects relating to hydrocarbon processing covered by groups C10G1/00 - C10G99/00
  • C10G2300/80—Additives
  • C10G2300/805—Water
  • C10G2300/807—Steam
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G2400/00—Products obtained by processes covered by groups C10G9/00 - C10G69/14
  • C10G2400/20—C2-C4 olefins

Definitions

• the invention relates to a method of making olefins from a crude or resid- containing crude fraction.
• Thermal cracking of hydrocarbons is a petrochemical process that is widely used to produce olefins such as ethylene, propylene, butylenes, butadiene, and aromatics such as benzene, toluene, and xylenes.
• olefins such as ethylene, propylene, butylenes, butadiene, and aromatics such as benzene, toluene, and xylenes.
• the olefins may be oligomerized (e.g., to form lubricant basestocks), polymerized (e.g., to form polyethylene, polypropylene, and other plastics), and/or functionalized (e.g., to form acids, alcohols, aldehydes and the like), all of which have well- known intermediate and/or end uses.
• One thermal cracking process is steam cracking, which involves cracking hydrocarbons at elevated temperatures in the presence of steam or gas mixtures containing steam.
• a hydrocarbon feedstock such as naphtha, gas oil, or other non-resid containing fractions of whole crude oil, which may be obtained, for instance, by distilling or otherwise fractionating whole crude oil
• steam cracking utilizes a pyrolysis furnace that generally has two main sections: a convection section and a radiant section.
• the hydrocarbon feedstock enters the less severe convection section of the furnace as a liquid (except for light feedstocks which enter as a vapor) wherein it is heated and vaporized by indirect contact with hot flue gas from the radiant section and optionally by direct contact with steam.
• the vaporized feedstock (and optional steam) mixture is then conveyed (typically through crossover piping) into the radiant section where it is quickly heated, at pressures typically ranging from about 10 to about 50 psig (69 to 345 kPa), to a severe hydrocarbon cracking temperature, such as in the range of from about 1450°F (788°C) to about 1650°F (900°C), to provide thorough thermal cracking of the feedstream.
• a severe hydrocarbon cracking temperature such as in the range of from about 1450°F (788°C) to about 1650°F (900°C)
• the effluent from the pyrolysis furnace contains gaseous hydrocarbons of great variety, e.g., saturated, monounsaturated, and polyunsaturated, and can be aliphatic and/or aromatic, as well as significant amounts of molecular hydrogen (H 2 ).
• the cracked product is then further processed such as in the olefin production plant to produce, as products of the plant, the various separate individual streams of high purity, i.e., hydrogen, the light olefins ethylene, propylene, butylenes, and aromatic compounds, as well as other products such as pyrolysis gasoline and pyrolysis gas oils.
• U.S. Patent No. 4,975,181 discloses an improved process and apparatus for the pyrolysis of a heavy hydrocarbon feed utilizing a transfer line reactor wherein pyrolysis reaction temperatures are achieved by contact of the heavy hydrocarbon feed with heated solid particles immediately followed by quenching of the pyrolysis gaseous effluent with cooled solid-particles in the transfer line reactor to maximize ethylene production and minimize the effect of secondary reactions.
• the present invention is directed to a process, preferably a continuous process, for cracking a hydrocarbon feed containing resid, comprising: heating a hydrocarbon feedstock containing resid; passing said heated hydrocarbon feedstock to a vapor/liquid separator (such as a knock-out drum); flashing said heated hydrocarbon feedstock in said vapor/liquid separator to form a vapor phase (such as an overhead vapor phase) and a liquid phase containing said resid; passing at least a portion of said resid- containing liquid phase from said vapor/liquid separator to a thermal conversion reactor containing coke particles, (preferably the thermal conversion reactor is operating at 1200°F (649°C) or more); and converting at least a portion of said resid into olefins.
• a vapor/liquid separator such as a knock-out drum
• the coke particles are present in the reactor at a coke particle/fresh feed ratio (wt/wt) of at least 1 : 1, based on the weight of circulating coke solids and fresh feed entering the reactor.
• a reactor or reaction zone is stated to be “operating at” a certain temperature it means that material in the reactor or zone has been heated to that temperature.
• the solids circulation is preferably adjusted to provide a hot coke/fresh resid feed ratio (wt/wt) in the contacting zone of at least 3: 1, preferably above 5 :1, and preferably above 8: 1, preferably up to about 30: 1 preferably with short contacting times on the order of seconds (typically 0.5 to 30 seconds, preferably 1 to 10 seconds, preferably 1.5 to 5 seconds).
• this ratio could be similar or somewhat lower (such as 0.1 : 1 to 30: 1) and include longer contacting times in the range of
• the thermal conversion reactor is a transfer line reactor integrated with a fluidized coker, and the process further comprises combining said resid-containing liquid bottoms phase with coke particles extracted from said fluidized coker to form a fluidized mixture within said transfer line reactor.
• the process further comprises separating said coke particles from said olefins exiting said transfer line reactor with at least one cyclone separator and passing said coke particles into a steam-air gasifier incorporated within said fluidized coker.
• the process comprises mixing said resid containing liquid bottoms phase with an effluent from a fluidized catalytic cracking (FCC) reactor containing FCC catalyst fines, prior to passing said liquid phase to said transfer line reactor.
• FCC fluidized catalytic cracking
• the process further comprises recycling said FCC catalyst fines and said coke particles between said transfer line reactor and said fluidized coker, such that the concentration of FCC catalyst fines achieves a steady state level between 5 wt% and 25 wt% of the circulating solids.
• the hydrocarbon feedstock is heated in a convection section of a steam cracking furnace, and said vapor/liquid separator (such as a knock-out drum) is integrated with said steam cracking furnace.
• said vapor/liquid separator such as a knock-out drum
• said hydrocarbon feedstock contains at least 1 wt% resid, preferably at least 10 wt% resid, preferably at least 20 wt% resid, typically between 10 wt% and 50 wt% of resid.
• the hydrocarbon feedstock contains at least 1 wt% 566°C + resid, preferably at least 10 wt% 566°C + resid, preferably at least 20 wt% 566°C + resid, typically between 10 wt% and 50 wt% of 566°C + resid.
• said olefins are combined with a product stream from a steam cracking furnace.
• the temperature within the thermal conversion reactor is from 649°C to 1000°C, preferably from 700°C to 900°C, typically from 700°C to 800°C.
• the present invention is also directed to a system, preferably continuous, for cracking hydrocarbon feedstock containing resid comprising: a steam cracking furnace having a vapor/liquid separator (such as a knock-out drum) integrated with a convection section of said furnace; and a fluidized coker comprising: a fluidized bed gasifier, a transfer line reactor comprising a hydrocarbon feed inlet in fluid communication with a lower portion of said knock-out drum, and a pyrolysis product outlet line, a solids conduit connecting a lower portion of said fluidized bed gasifier with said transfer line reactor, and at least one cyclone separator having an inlet connected to said pyrolysis product outlet line, a cracked product outlet at a top portion of said cyclone separator, and a solids outlet at the bottom of said cyclone separator.
• a steam cracking furnace having a vapor/liquid separator (such as a knock-out drum) integrated with a convection section of said furnace
• the system further comprises an air/steam inlet at the bottom of said fluidized bed gasifier.
• the fluidized bed coker further comprises a fluidized bed heater vessel, having recirculating solids conduits, preferably two solids conduits, connecting lower portions of said heater vessel and said gasifier, and at least one gas conduit connected between an upper portion of said gasifier and the lower portion of said heater vessel.
• the cyclone separator solids outlet is connected to either or both of said fluidized bed gasifier or said heater vessel.
• the transfer line reactor is a vertical riser reactor, wherein said solids conduit and said hydrocarbon feed inlet are connected to a lower portion of said reactor.
• the transfer line reactor is a downflow reactor, wherein said solids conduit and said hydrocarbon feed inlet are connected to an upper portion of said reactor.
• C2-C4 hydrocarbons are produced in the thermal conversion reactor and said C2-C4 hydrocarbons are further converted by recycling to a steam cracking furnace.
• any process described here is a continuous process.
• continuous is meant that the process operates without cessation or interruption.
• a continuous process to produce olefins would be one where the reactants are continually introduced into one or more reactors and olefin product is continually withdrawn.
• Figure 1 is a flow diagram of an embodiment of the present invention process.
• Figure 2 is a diagram of a thermal conversion reactor useful in the present process.
• This invention discloses methods, preferably continuous methods, for producing chemicals, (such as olefins and or other cracked components such as lighter hydrocarbons) from heavy feedstocks in a manner where a high fraction of vacuum resid is more efficiently converted to chemicals (such as olefins and or other cracked components such as lighter hydrocarbons).
• the invention involves combination of a steam cracker having an integrated knock-out drum with a high temperature fluid coker or FlexicokerTM.
• the resid-containing effluent from a knock-out drum such as a knock-out drum which is integrated with the convection section of a steam cracking furnace
• a thermal conversion reactor such as a fluidized coker
• desired products including olefins which can be combined with a product stream exiting the radiant section of one or more steam crackers.
• thermal pyro lysis unit, pyro lysis unit, steam cracker, and steamcracker are used synonymously herein; all refer to what is conventionally known as a steam cracker, even though the use of steam is optional.
• a crude oil or fraction thereof containing resid is utilized as a feedstock for a steam cracking furnace.
• Suitable lower value feeds may typically include heavier crudes, those hydrocarbon feedstocks that have high concentrations of resid, high sulfur, high Total Acid Number (TAN), high aromatics, and/or low hydrogen content.
• Crude as used herein, means whole crude oil as it issues from a wellhead, production field facility, transportation facility, or other initial field processing facility, optionally including crude that has been processed by a step of desalting, treating, and/or other steps as may be necessary to render it acceptable for conventional distillation in a refinery. Crude as used herein is presumed to contain resid.
• Crude fractions are typically obtained from the refinery pipestill. Although any crude fraction obtained from the refinery pipestill may be useful in the present invention, a significant advantage offered by the present invention is that crude or crude fractions still containing all or a portion of the original resid present in the whole crude obtained from the wellhead may be used as feed for a steam cracker.
• the crude or other feedstock to the present system may comprise at least about 1 wt% resid, preferably at least about 5 wt% resid, and more preferably at least about 10 wt% resid up to about 50 wt% resid, preferably at least about 1 wt% 566°C + resid, preferably at least about 5 wt% 566°C + resid, and more preferably at least about 10 wt% 566°C + resid up to about 50 wt% 566°C + resid.
• Resid as used herein refers to the complex mixture of heavy petroleum compounds otherwise known in the art as residuum or residual.
• Atmospheric resid is the bottoms product produced in atmospheric distillation where the endpoint of the heaviest distilled product is nominally 650°F (343°C), and is referred to as 650°F + (343°C + ) resid.
• Vacuum resid is the bottoms product from a column under vacuum where the heaviest distilled product is nominally 1050°F (566°C), and is referred to as 1050°F + (566°C + ) resid.
• At least a portion of the 650°F + resid, up to at least the 1050°F + (566°C + ) boiling point fraction, is vaporized, such as when combined with steam, and/or when the pressure is reduced or flashed in the knock-out drum of the steam cracker.
• Resid typically contains a high proportion of undesirable impurities such as metals, sulfur and nitrogen, as well as high molecular weight (C12 ) naphthenic acids (measured in terms of TAN according to ASTM D-664, TAN refers to a total acid number expressed as milligrams ("mg") of KOH per gram ("g") of sample).
• C12 high molecular weight naphthenic acids
• this invention can be practiced on 566°C + resid having: one or more (preferably two, three, four, five, six or seven) of the following properties: 1) 50 ppm of Ni or more, alternately 100 ppm or more, alternately 125 ppm or more, based upon the weight of the 566°C + resid; and/or 2) 200 ppm vanadium or more, alternately 500 ppm or more, alternately 900 ppm or more, based upon the weight of the 566°C + resid; and/or 3) 4 wt% sulfur or more, alternately 5 wt% or more, alternately 6 wt% or more, based upon the weight of the 566°C + resid; and/or 4) a TAN of at least 0.1, alternately at least 0.3, alternately from about 0.1 to about 20, about 0.3 to about 10, or about 0.4 to about 5; and/or 5) an API gravity of 19 or less (AST)
• Examples resids that can be used herein are the 566°C + resids obtained from crudes including, but not limited to, crudes from of the following regions of the world: U.S. Gulf Coast, southern California, north slope of Alaska, Canada tar sands, Canadian Alberta region, Mexico Bay of Campeche, Argentinean San Jorge basin, Brazilian Santos and Campos basins, Egyptian Gulf of Suez, Chad, United Kingdom North Sea, Angola Offshore, China Bohai Bay, China Karamay, Iraq Zagros, Ukraine Caspian, Nigeria Offshore, Madagascar northwest, Oman, Netherlands Schoonebek, Venezuelan Zulia, Malaysia, and Indonesia Sumatra. Additional resids useful herein include 566°C + resids obtained from crude oils described as "disadvantaged" in U.S. 7,678,264, incorporated by reference herein.
• the resid-containing feed may be passed into the convection section of a pyrolysis unit, where it is heated. Then the heated feed may be passed to a pressure reduction device or flash separation drum, which is integrated with the pyrolysis furnace, to drop out the heaviest fraction (e.g., substantially the asphaltenes).
• flash drum flash pot
• knock-out drum knock-out pot
• flash drum means generally to effect a phase change for at least a portion of the material in the vessel from liquid to vapor, via a reduction in pressure and/or an increase in temperature.
• An integrated knock out drum is a vapor/liquid separator that is in fluid communication with a steam cracker.
• the integrated knock-out drum is in fluid communication with the convection section of a steam cracker, where feedstock is heated (optionally mixed with superheated steam) and transferred to said knock-out drum operating as a vapor/liquid separator, thereafter the vapors from the knock-out drum are returned to the steam cracker, preferably either to the convection or radiant section, or both.
• the addition of steam may further assist flash separation by reducing the hydrocarbon partial pressure, assist in conversion and vaporization of the 750°F + (399°C + ) to 1050°F + (566°C + ) (preferably even a substantial portion of the 1100°F + (593°C + )) resid fractions, and prevent fouling.
• the vapor/liquid separator operates at a temperature and pressure where those portions of the feed material that cause coking are kept in a liquid state, preferably the vapor/ liquid separator operates at a temperature of between about 375 to 525°C, preferably from 400 to 500°C, preferably from 800°F (about 425°C) and about 870°F (about 465°C), but also typically not over about 900°F (about 482°C). Flashing material through the flash drum to obtain an overhead vapor and liquid bottoms further facilitates vaporization of a major fraction of the 650°F + (343°C + ) to 1050°F + (566°C + ) fraction of the resids.
• a steam cracking furnace (also referred to as a "steam cracker”) is a pyrolysis furnace that has two main sections: a convection section and a radiant section, where hydrocarbon feedstock enters the less severe convection section of the furnace as a liquid (except for light feedstocks which enter as a vapor) and where the feedstock is heated and vaporized by indirect contact with hot flue gas from the radiant section and optionally by direct contact with steam.
• the vaporized feedstock and steam mixture (if present) is then introduced (typically through crossover piping) into the radiant section where it is quickly heated, at pressures typically ranging from about 10 to about 50 psig (69 to 345 kPa), to a severe hydrocarbon cracking temperature, such as in the range of from about 1450°F (788°C) to about 1650°F (900°C), to provide thorough thermal cracking of the feedstream.
• the resulting products typically comprise olefins.
• the fluid coker preferably includes an integrated air gasifier (or partial oxidation reactor) which is used to convert coke to fuel gas by steam/air gasification and combustion at between about 1400-1800°F (760-982°C).
• This gasification can be facilitated by cofeeding oxygen or by using oxygen enriched air.
• Hot, partially gasified coke from this gasification reaction is continuously withdrawn from the gasifier and fed to one or more solids transfer lines where it is contacted with the bottoms material recovered from one or more steam cracking furnaces equipped with integrated vapor/liquid separators (such as knock-out drums).
• This residual oil fraction is converted at 1300-1800°F (704-982°C) to a mixture of lighter hydrocarbons containing high concentrations of ethylene and propylene.
• the transfer line reactors can be configured in several ways, a preferred configuration is similar to that used in fluid catalytic cracking units; e.g., the transfer line is operated as a vertical riser reactor where the hot solids are contacted with feed near the bottom of the riser, the solids and vapor are transported upward along the riser, and the solids and vapor are separated using one or more cyclones in series.
• the transfer line can be operated as "downer" or downflow reactor. Irrespective of the specific configuration, the transfer line reactor is highly effective for contacting hot coke with the residual oil.
• the hot coke provides the heat needed to fully convert the residual oil feed to lighter hydrocarbons in short reaction times of about 0.1-10 seconds, preferably about 1 second, and to coke which is deposited on previously formed coke particles.
• the thermal conversion reactor preferably a transfer line reactor, contains at least 0.1 wt% coke particles, based upon the weight of the circulating solids in the thermal conversion reactor, preferably 1 to 30 wt%, preferably from 3 to 25 wt%, preferably from 5 to 25 wt%.
• a primary feature of the present invention is the direct use of hot gasifier coke as a heat transfer medium for high temperature coking of residual oil for producing chemicals.
• This embodiment differs substantially from prior art related to the fluid coking processes.
• the inventors have unexpectedly discovered that high temperature coking is effective for producing chemicals (such as olefins and or other cracked components such as lighter hydrocarbons), especially when integrated with a steam cracker equipped with integrated vapor/liquid separators (such as knock-out drums).
• knock-out drum may be taken to generally refer to any vapor/liquid separator device.
• a heavy feedstock 100 containing 1 wt% or more (typically about 10-50 wt%) molecules boiling in the vacuum resid range (566°C ) is fed to a first steam cracking furnace 200 which includes an integrated knock-out drum 205.
• the whole feed is heated to about 400-470°C in the convection section 206 of the furnace.
• the whole feed passes through line 207 into the knock-out drum separation device 205 where molecules boiling below about 538-593°C are vaporized (or remain vaporized) and are separated from heavier compounds which remain in the liquid phase (pressure reduction and/or steam stripping, among other things, in the drum can be used to cause additional molecules to vaporize).
• Material typically enters the drum at a temperature of about 400-470°C and vaporization is facilitated by the use of steam stripping or stripping with light hydrocarbons.
• the vapors pass through line 210 into the radiant section 250 of the first steam cracking furnace 200 (either directly or via a heater, such a transfer line heater or a convection section of the steam cracker), whereas the heavy liquids are withdrawn from the bottom of the knock-out drum through line 220.
• This material that is removed from the bottom of the knock-out drum then serves as the primary feedstock for the high temperature coking apparatus 300.
• Heavy liquids from several knock-out drum equipped furnaces are preferably combined to achieve better economy of scale in the high temperature fluid coker process. If the unit is located in a large refinery complex, it is possible to combine supplemental residual oil feedstock 230 from the refinery with that recovered from the knock-out drums.
• Another potential feedstock from the steam cracker is the heavy fractions (or steam cracked tar) produced from steam cracking of gas oil fractions.
• products from the steam cracking reaction 252 are combined with hydrocarbon products from the high temperature coking reaction 310 before separation into a series of fuel and chemical products such as olefins and or other cracked components such as lighter hydrocarbons).
• hydrocarbon products from the high temperature coking reaction 310 are combined with hydrocarbon products from the high temperature coking reaction 310 before separation into a series of fuel and chemical products such as olefins and or other cracked components such as lighter hydrocarbons).
• hydrocarbon products from the high temperature coking reaction 310 such as olefins and or other cracked components such as lighter hydrocarbons.
• C 4 " hydrocarbons are gases with weights at or below C 4 , including methane, ethane, ethylene, propylene, propane, butenes, butanes, hydrogen, and the like.
• These major product streams are then further separated and purified using typical methods for the refining and chemicals industry such as fractionation and hydroprocessing.
• Fuel gas (CO, C0 2 and H 2 ) created during the high temperature coking process is withdrawn from the coker 300 via line 320 and/or 346 for use elsewhere in the process, described below.
• One of the important advantages of the integrated coking and steam cracking configuration is that light paraffins, such as ethane and propane that are produced in the coking reaction, can be easily recycled to one of the steam cracking furnaces for conversion to ethylene and propylene.
• the residual oil feedstock to the high temperature coking reactor is mixed with minor amounts of heavy cycle oil (HCCO) 215 from a fluid cat cracking (FCC) process.
• HCCO heavy cycle oil
• the heavy cycle oil normally boils in the range of about 454 to 593°C and normally contains small levels (0.01 to 2-3 wt%) of FCC catalyst fines. These fines are produced by attrition of FCC catalyst particles during the FCC process.
• the high temperature coker operates in a cyclic manner, described in more detail below, where the coke particles are circulated between the gasifier, heater, and reactor, multiple passes are required before the coke particles are fully converted or otherwise removed as purge. Therefore, it is possible to build a moderately high concentration (5-25 wt%) of catalyst fines into the circulating solids inventory.
• FIG. 2 provides a simplified diagram to further illustrate the process and apparatus for high temperature coking.
• the fluidized coker 300 includes an air gasifier 340 which operates as a dense phase fluidized bed reactor at about 871-1037°C, preferably about 954°C.
• Air and steam 342 are fed to the gasifier using a series of distributors or nozzles which are incorporated in a grid plate 345 within the gasifier.
• the reaction of air and steam with the coker particles converts part of the coke to a mixture of gases primarily including CO, CO 2 , H 2 (fuel gas).
• the coke partial oxidation reaction which occurs in the gasifier is exothermic and produces the heat needed to drive the endothermic coking reaction.
• Energy balance is achieved by balancing the rates at which air and steam are fed to the gasifier with the rate of coke removal through solids line 333 for use in the coking reaction, the feed rate to the coker, and coke withdrawal to the "heater” vessel 350 through line 348, and processing temperatures within the different sections of the unit.
• Slide valves or other means can be used to adjust the solids circulation rates and pressure balance within the system.
• Residual oil from the steam cracker integrated knock-out drum and/or other refinery resid-containing feed 220/230 is fed to one or more transfer line reactors 330 which are supplied with hot circulating coke from the air gasifier 340 through line 333.
• the heavy oil is converted in the transfer line reactor (such as a riser or standpipe), exits through line 305, and the cracked vapors 310 are separated from the solids using cyclones 335 (or other separation devices) and optionally stripping with steam or other process gas.
• the coking reaction converts part of the feedstock (typically 15-40%) to new coke deposits on the coke particles.
• coke is removed from the cracked gas and returned to the gasifier 340 through line 315, where it is further converted by air gasification.
• the decision whether to disengage coke into the heater or the gasifier is determined by the specific unit design, the gasifier operating pressure, and operating features such as the feed quality or crackability. Both approaches are fully feasible and fall within the overall scope of the invention. In both approaches it will be advantageous to steam strip the coke to increase recovery of cracked products.
• Product gas 346 from the gasifier is removed overhead from the gasifier 340 directly or more typically by routing to the heater for partial cooling and collection overhead using internal cyclones and suitable piping.
• the processing unit includes at least another fluidized bed labeled as the heater 350.
• This vessel can have several functions with the primary role to partially cool the gasifier product gases (as noted above) and moderate and maintain overall heat balance and solids circulation. Hot solid coke particles are circulated between the gasifier 340 and the heater 350 using solids transfer lines 348 and 352.
• the heater is maintained at a much lower average bed temperature as compared to the gasifier, typically 315-537°C.
• Hot product fuel gas 346 from the gasifier 340 is routed to the heater 350 where it is cooled to approximately the heater operating temperature.
• This gas and optionally steam are used to fluidize the coke within the heater 350.
• the cooled fuel gas 320 has medium BTU content and can be subsequently used as fuel for furnaces or power generating equipment within the refinery or chemical plant. It is also possible to use the heater for preheating the residual oil feed to the coking reaction. This can be accomplished using heat exchangers within the vessel (not shown). Likewise, it is also possible to remove part of the coke from the heater as a purge stream 355. This is particularly useful to improve operating efficiency when the feed to the coking reaction has higher metal or mineral content.
• this second vessel can be helpful in improving unit energy efficiency and operability, it is also possible to design a unit with a single vessel so as to reduce investment and operating complexity.
• One of the major advantages of the fluid coking process for producing chemicals from heavy residual oils is the ability to utilize lower quality feeds which may contain metals or other forms of mineral matter with a high degree of flexibility.
• Other known processes, such as high temperature catalytic cracking or catalytic pyrolysis are not able to effectively utilize such feeds.
• this invention relates to:
• a process for cracking a hydrocarbon feed containing resid comprising:
• thermal conversion reactor is a transfer line reactor and the coke particle/fresh feed ratio (wt/wt) in the transfer line reactor is in the range of about 3 : 1 to about 30: 1.
• said thermal conversion reactor is a transfer line reactor in fluid communication with a fluidized coker, and further comprising combining said resid-containing liquid phase with coke particles extracted from said fluidized coker to form a fluidized mixture within said transfer line reactor.
• a system for cracking hydrocarbon feedstock containing resid comprising:
• a steam cracking furnace having a vapor/liquid separator (e.g., a knock-out drum) in fluid communication (e.g., integrated) with said furnace (typically the convection section of said furnace); and
• a vapor/liquid separator e.g., a knock-out drum
• a transfer line reactor comprising a hydrocarbon feed inlet in fluid communication with a lower portion of said separator, and a pyrolysis product outlet line
• a solids conduit connecting a lower portion of said fluidized bed gasifier with said transfer line reactor, and iv) at least one cyclone separator having an inlet connected to said pyrolysis product outlet line, a cracked product outlet at a top portion of said cyclone separator, and a solids outlet at the bottom of said cyclone separator.
• said fluidized coker further comprises a fluidized bed heater vessel, having recirculating solids conduits connecting lower portions of said heater vessel and said gasifier, and at least one gas conduit connected between an upper portion of said gasifier and the lower portion of said heater vessel.
• this invention relates to:
• a process for cracking a hydrocarbon feed containing resid comprising:
• thermal conversion reactor is a transfer line reactor in fluid communication with a fluidized coker, and further comprising combining said resid-containing liquid bottoms phase with coke particles extracted from said fluidized coker to form a fluidized mixture within said transfer line reactor.
• a system for cracking hydrocarbon feedstock containing resid comprising:
• a transfer line reactor comprising a hydrocarbon feed inlet in fluid communication with a lower portion of said separator, and a pyrolysis product outlet line
• At least one cyclone separator having an inlet connected to said pyrolysis product outlet line, a cracked product outlet at a top portion of said cyclone separator, and a solids outlet at the bottom of said cyclone separator.
• said fluidized bed coker further comprises a fluidized bed heater vessel, having recirculating solids conduits connecting lower portions of said heater vessel and said gasifier, and at least one gas conduit connected between an upper portion of said gasifier and the lower portion of said heater vessel.
• a process for cracking a hydrocarbon feed containing resid comprising:
• a process for cracking a hydrocarbon feed containing resid comprising: (a) heating a hydrocarbon feedstock containing from 10 wt% to 50 wt% of 566°C resid having a TAN of at least 0.1 and a C5 asphaltenes content of at least 0.04 grams of C5 asphaltenes per gram of resid in a convection section of a steam cracking furnace;

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• 2011
  • 2011-06-09 EP EP11726295.6A patent/EP2591069A1/de not_active Withdrawn
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  • 2011-06-09 CN CN201180033757.5A patent/CN103003394B/zh not_active Expired - Fee Related
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