US3843744A - Controlling coke in the pyrolysis of hydrocarbons to acetylene and hydrogen - Google Patents

Controlling coke in the pyrolysis of hydrocarbons to acetylene and hydrogen Download PDF

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Publication number
US3843744A
US3843744A US00225719A US22571972A US3843744A US 3843744 A US3843744 A US 3843744A US 00225719 A US00225719 A US 00225719A US 22571972 A US22571972 A US 22571972A US 3843744 A US3843744 A US 3843744A
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United States
Prior art keywords
reactor
pyrolysis
coke
steam
hydrogen
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Expired - Lifetime
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US00225719A
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English (en)
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L Kramer
J Happel
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Priority to BE795403D priority Critical patent/BE795403A/xx
Application filed by Individual filed Critical Individual
Priority to US00225719A priority patent/US3843744A/en
Priority to FR7304885A priority patent/FR2172148B1/fr
Priority to NL7301998A priority patent/NL7301998A/xx
Priority to JP48017131A priority patent/JPS5238002B2/ja
Priority to IT20297/73A priority patent/IT979033B/it
Priority to BR731095A priority patent/BR7301095D0/pt
Priority to DE19732307300 priority patent/DE2307300A1/de
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Publication of US3843744A publication Critical patent/US3843744A/en
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    • 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
    • C10G9/14—Thermal non-catalytic cracking, in the absence of hydrogen, of hydrocarbon oils in pipes or coils with or without auxiliary means, e.g. digesters, soaking drums, expansion means
    • C10G9/16—Preventing or removing incrustation
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B3/00—Hydrogen; Gaseous mixtures containing hydrogen; Separation of hydrogen from mixtures containing it; Purification of hydrogen
    • C01B3/02—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen
    • C01B3/32—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air
    • C01B3/34—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air by reaction of hydrocarbons with gasifying agents
    • C01B3/36—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air by reaction of hydrocarbons with gasifying agents using oxygen or mixtures containing oxygen as gasifying agents
    • C01B3/363—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air by reaction of hydrocarbons with gasifying agents using oxygen or mixtures containing oxygen as gasifying agents characterised by the burner used
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S585/00—Chemistry of hydrocarbon compounds
    • Y10S585/949—Miscellaneous considerations
    • Y10S585/95—Prevention or removal of corrosion or solid deposits

Definitions

  • ABSTRACT A method for controlling and diminishing the forma- I tion of coke on the walls of reactors wherein hydrocarbons are undergoing pyrolysis and especially pyrolysis for formation of acetylene, which comprises injection of steam and/or an inert gas at at least one critically located point in the system downstream from the feed injection.
  • the improvement step prolongs the period of introduction of feed to the pyrolysis by reducing the frequency of feed interruption in order to remove coke build-up.
  • This invention relates to an improved method for controlling the formation of coke on the walls of reactors wherein hydrocarbon pyrolysis is conducted.
  • this invention relates to an improvement in high temperature pyrolysis systems for hydrocarbons wherein the desired product is acetylene, and the other principal components of the product stream are mainly hydrogen and lesser amounts of methane and ethylene.
  • Coke formation on the walls of hydrocarbon pyrolysis equipment is undesirable in that the coke is cumulative and eventually restricts the flow of the feed gas to such a great extent that the pyrolysis process must be interrupted for removal of the coke.
  • this coke cannot otherwise be controlled, it is burned-off in cycles by substituting an oxidizing gas such as air, steam, carbon dioxide or oxygen for the hydrocarbon feed. It is obviously desirable and particularly in commercial operations to extend the pyrolysis cycle as much as possible, because the coke removal cycle is a non-productive period and damaging to the reactors.
  • the combined concentrations of CO and CO produced ranged from 12.5 to 239 percent of the combined concentrations of ethylene and acetylene produced.
  • the increased production of CO and CO follows conditions of increased severity of pyrolysis i.e., increasing temperature and- /or increasing reaction time).
  • the feed used was 34.1 mole percent methane and the remainder hydrogen at 31.2 X 10" standard cubic feet per sec (0C, 760 mm Hgab).
  • the maximum profile temperature was 1,700C. to 1,725C., at We inches from quench (reactor outlet). At the start of feed flow the reactor volume appears completely clear and the quench appears as a dark disc at the bottom of the bright reactor walls.
  • second sheet of coke is growing from wall on top of first sheet Pin hole in sheet closed; new hole opened Solid sheet across reactor with either cracks or platelet edges showing zero 1 OLII Mechanical probing of the sheet indicated that it was very thin, less than one-eighth inch thick. No other coke was observable until this thin zone, located between the maximum reactor profile temperature and the quench, but much closer to the quench, was substantially blocked. Only then did coke appear upstream and it had the appearance of water droplets on a swcating pipe. Similar results were obtained. for example, with a feed containing 25.6 molc methane except that the rate of coke growth was slower.
  • Free radicals present and relatively stable at the higher temperatures of the reaction zone, first reach a temperature where they can recombine as coke precursors and/or initiate polymerization.
  • Tmax is that location (point) in the reactor which is approximately at the maximum temperature observed within the reactor and which is furthest downstream (closest to the quench).
  • the gaseous stream would necessarily be injected downstream of the high temperature zone of the reactor.
  • Both steam and hydrogen are reactive gases at high temperatures and may be expected to react with radicals or highly unsaturated coke precursors. Both gases would act to dilute the products and in this way reduce the rates of polymerization and the dew point of coke precursors. Steam has the additional advantage that even at temperatures substantially below Tmax, it reacts with coke, and therefore could be expected to reduce the net rate of coke formation still further. Both steam and hydrogen were also considered to be interesting from a practical point of view in that both are This, in conjunction with the paragraphs that follow should distinguish between steam and/or H in our process and either or both as a quench-or diluent.
  • the injected gas i.e., steam and/or hydrogen
  • the temperature and time for the water gas reaction are thus both minimal, the production of carbon oxides is greatly reduced.
  • FIG. 2 is a diagrammatic representation of the elements of an apparatus wherein the metered hydrocarbon feed in line 1 which may be suitably diluted with hydrogen if desired is passed through one or more meter valves and then caused to pass through an electrically heated reaction chamber 3 and is then rapidly quenched in quenching chamber 4.
  • a separate and distinct, metered steam flow which may be diluted with a non-condensible carrier gas, preferably hydrogen, is admitted to a ceramic tube 6 passing through the same electrically heated re action chamber.
  • a non-condensible carrier gas preferably hydrogen
  • Thehydrocarbon feed suitably diluted with hydrogen which is either premixed therewith or fed separately, is withdrawn from storage, metered and passed through suitable control valves. The pressure of the feed is measured and this feed stream proceeds to the electrically heated reactor 3.
  • a metered stream of steam and carrier is admitted to the ceramictube 11 via lines 2 and 5 which tube passes through the reactor.
  • a suitable reactor for carrying out the herein described'process is seen in inside elevational view in FIG. 3 and in cross section in FIG. 4.
  • the reactor isseen to be FIG. 4
  • a concentric system of cylindrical tubes (or layers) which are progressively larger in diameter.
  • the smallest and innermost tube 101 is ceramic and carries the steam through the reactor to the vent point 102 where it is admixed with, the hydrocarbon product stream which flows in the annular space 104 between this innermost ceramic tube and the next size ceramic tube (i.e., the reactor tube) 103 concentric with it.
  • the vent point is conveniently located just upstream of the point at which the sheet of coke forms.
  • the ceramic steam and reactor tubes are 3/l6 inch outside diameter (OD) (101) and 5 4 inch inside diameter (I.D.) (103) respectively and the annulus 104 positioned between the larger diameter reactor tube and the smaller diameter steam tube thus constitutes the reactor cross section of 1/32 inch nominal width.
  • the narrow annulus 104 was not chosen because its performance I i.e., operating time: Time in Table 3) is the best, but because is very sensitive to coke and thus offers readily and quickly available comparisons of coking rates under different experimental conditions. Since it is unlikely that any production design would have smaller clearances, the operating times presented in Table 3 may be considered in the minimal ranges of those which would be encountered in larger reactors.
  • the ceramic reactor tube (alumina) is positioned within the graphite resistance element 105 designed to use low voltage electrical power up to 3.5KVA, thus providing sufficient heat to effect the maximum temperature within the reactor and steam tubes so described hereinabove, e.g., l,750C. the optimum temperature for production of acetylene.
  • Successive cylindrical walls of refractory 106 and insulation 107 are refractory walls of zirconia 106 and aluminum silicate insulation 107 within a furnace outer wall 108 of aluminum are desirably employed.
  • the outer walls of the reactor are preferably water cooled.
  • a window 7 FIG. 2) is positioned in the outer cylindrical wall 108 of the reactor to permit observation by an optical pyrometer sighting on the outer wall of the ceramic reactor tube (through slits in the insulation, refractory and graphite resistance element); thus a means for determining the temperature thereof is conveniently provided.
  • the combined effluent stream containing product and byproduct, steam and carrier enters the quenching chamher 4 where rapid cooling of the hot effluent gas to a ture reduction by dilution. Additional cooling in a water cooled heat exchanger 10 for example further reduces the temperature of the effluent to ambient temperatures thus causing further condensation of the steam. Condensate and soot are desirably separated from the effluent; for instance this can be accomplished in Cyclone separator 9. Analysis of the gaseous effluent components'is accomplished by gas chromotography.
  • the temperature of the steam at the point it is admixed with the product effluent is the same as the reaction zone temperature at this point, this is not necessarily a requirement for operation of the invention and to obtain its advantages it is required only that the injected gas, e.g., steam, be hot, i.e., over 750C. If steam temperature is higher than the reactor temperature, the production of carbon oxides is increased.
  • the injected gas e.g., steam
  • the gas e.g., steam
  • the gas comes in parallel, but separate from the feed.
  • Other means for introducing this steam are also suitable and may be used; illustrative of but not intended to be limitative thereof, are countercurrent injection through the reactor exit (quench zone), and also, through a break in the reactor wall such that the gas enters the reactor perpendicular to the direction of feed flow from outside the reactor.
  • parallel flow is the least desirable technique.
  • the point of secondary gas injection is best determined by experimentally conducting a short pyrolysis cycle until the pressure drop across the reactor (inlet to quench) is about one-eighth of the pressure in the reactor.
  • Table 3 shows the operating conditions and results obtained during three sets of experimental runs 2a, b, and c; 3a, b, and c; and 4a, b, and 0.
  • the pyrolysis cycle with steam is substantially longer than the cycle with hydrogen and both are much longer than that with no gas injected other than the feed.
  • the pyrolysis cycle time with hydrogen injection alone is increased over a range of 60 to 150 percent and the improvement with steam increased over a range of 100 to 200 percent as compared to the reactor operation without the invention. All times taken are that time to reach a pressure drop of one-half psi.
  • the yield of CO can easily be limited to less than 5 percent of feed disappearance where a substantial portion of feed disappearance over percent, in all examples, has been converted to acetylene.

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  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Organic Chemistry (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Engineering & Computer Science (AREA)
  • Inorganic Chemistry (AREA)
  • Combustion & Propulsion (AREA)
  • General Health & Medical Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • General Chemical & Material Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)
  • Physical Or Chemical Processes And Apparatus (AREA)
US00225719A 1972-02-14 1972-02-14 Controlling coke in the pyrolysis of hydrocarbons to acetylene and hydrogen Expired - Lifetime US3843744A (en)

Priority Applications (8)

Application Number Priority Date Filing Date Title
BE795403D BE795403A (fr) 1972-02-14 Procede pour empecher la formation de coke au cours de la pyrolyse d'hydrocarbures en acetylene et hydrogene
US00225719A US3843744A (en) 1972-02-14 1972-02-14 Controlling coke in the pyrolysis of hydrocarbons to acetylene and hydrogen
FR7304885A FR2172148B1 (enrdf_load_stackoverflow) 1972-02-14 1973-02-12
JP48017131A JPS5238002B2 (enrdf_load_stackoverflow) 1972-02-14 1973-02-13
NL7301998A NL7301998A (enrdf_load_stackoverflow) 1972-02-14 1973-02-13
IT20297/73A IT979033B (it) 1972-02-14 1973-02-13 Procedimento perfezionato per il controllo della formazione di coke nella pirolisi di idrocarbu ri in acetilene e idrogeno
BR731095A BR7301095D0 (pt) 1972-02-14 1973-02-14 Um processo aperfeicoado para controlar e diminuir a formacao de coque yas paredes de reatores de pirolise
DE19732307300 DE2307300A1 (de) 1972-02-14 1973-02-14 Verfahren zur verminderung einer bildung von koks an waenden von reaktoren fuer die thermische spaltung von kohlenwasserstoffen

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US00225719A US3843744A (en) 1972-02-14 1972-02-14 Controlling coke in the pyrolysis of hydrocarbons to acetylene and hydrogen

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JP (1) JPS5238002B2 (enrdf_load_stackoverflow)
BE (1) BE795403A (enrdf_load_stackoverflow)
BR (1) BR7301095D0 (enrdf_load_stackoverflow)
DE (1) DE2307300A1 (enrdf_load_stackoverflow)
FR (1) FR2172148B1 (enrdf_load_stackoverflow)
IT (1) IT979033B (enrdf_load_stackoverflow)
NL (1) NL7301998A (enrdf_load_stackoverflow)

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4012457A (en) * 1975-10-06 1977-03-15 Shell Development Company Thermal cracking method for the production of ethylene and propylene in a molten metal bath
US4166830A (en) * 1978-06-21 1979-09-04 Arand John K Diacritic cracking of hydrocarbon feeds for selective production of ethylene and synthesis gas
US4248692A (en) * 1979-08-29 1981-02-03 Kerr-Mcgee Chemical Corporation Process for the discharge of ash concentrate from a coal deashing system
US5346133A (en) * 1993-03-25 1994-09-13 The M. W. Kellogg Company High temperature liquid injection apparatus
WO1997002223A3 (en) * 1995-06-30 1997-02-13 Vitaly Lissianski Method for producing ethylene and other chemicals
US5942652A (en) * 1994-09-30 1999-08-24 Institut Français Du Petrole Ethane pyrolysis
US6406613B1 (en) 1999-11-12 2002-06-18 Exxonmobil Research And Engineering Co. Mitigation of coke deposits in refinery reactor units
US6585883B1 (en) 1999-11-12 2003-07-01 Exxonmobil Research And Engineering Company Mitigation and gasification of coke deposits
WO2003093206A1 (de) * 2002-05-02 2003-11-13 Uhde Gmbh Verfahren zur herstellung ungesättigter halogenhaltiger kohlenwasserstoffe sowie dafür geeignete vorrichtung
US6787024B2 (en) * 2001-07-10 2004-09-07 Exxonmobil Research And Engineering Company Process for reducing coke agglomeration in coking processes
WO2014111396A1 (de) * 2013-01-16 2014-07-24 Basf Se Verfahren zur herstellung von acetylen und synthesegas
US9802875B2 (en) 2013-08-29 2017-10-31 Basf Se Apparatus and process for preparing acetylene and synthesis gas
RU2637708C2 (ru) * 2012-06-14 2017-12-06 Басф Се Способ получения ацетилена и синтез-газа

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS57205258U (enrdf_load_stackoverflow) * 1981-06-19 1982-12-27
US5565087A (en) * 1995-03-23 1996-10-15 Phillips Petroleum Company Method for providing a tube having coke formation and carbon monoxide inhibiting properties when used for the thermal cracking of hydrocarbons
WO2012062784A1 (de) 2010-11-11 2012-05-18 Basf Se Verfahren und vorrichtung zur herstellung von acetylen und synthesegas
RU2591940C2 (ru) 2010-11-11 2016-07-20 Басф Се Способ и устройство для изготовления ацетилена и синтез-газа

Cited By (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4012457A (en) * 1975-10-06 1977-03-15 Shell Development Company Thermal cracking method for the production of ethylene and propylene in a molten metal bath
US4166830A (en) * 1978-06-21 1979-09-04 Arand John K Diacritic cracking of hydrocarbon feeds for selective production of ethylene and synthesis gas
US4248692A (en) * 1979-08-29 1981-02-03 Kerr-Mcgee Chemical Corporation Process for the discharge of ash concentrate from a coal deashing system
US5346133A (en) * 1993-03-25 1994-09-13 The M. W. Kellogg Company High temperature liquid injection apparatus
US5942652A (en) * 1994-09-30 1999-08-24 Institut Français Du Petrole Ethane pyrolysis
WO1997002223A3 (en) * 1995-06-30 1997-02-13 Vitaly Lissianski Method for producing ethylene and other chemicals
US6406613B1 (en) 1999-11-12 2002-06-18 Exxonmobil Research And Engineering Co. Mitigation of coke deposits in refinery reactor units
US6585883B1 (en) 1999-11-12 2003-07-01 Exxonmobil Research And Engineering Company Mitigation and gasification of coke deposits
US6787024B2 (en) * 2001-07-10 2004-09-07 Exxonmobil Research And Engineering Company Process for reducing coke agglomeration in coking processes
WO2003093206A1 (de) * 2002-05-02 2003-11-13 Uhde Gmbh Verfahren zur herstellung ungesättigter halogenhaltiger kohlenwasserstoffe sowie dafür geeignete vorrichtung
RU2637708C2 (ru) * 2012-06-14 2017-12-06 Басф Се Способ получения ацетилена и синтез-газа
WO2014111396A1 (de) * 2013-01-16 2014-07-24 Basf Se Verfahren zur herstellung von acetylen und synthesegas
CN104918879A (zh) * 2013-01-16 2015-09-16 巴斯夫欧洲公司 生产乙炔和合成气的方法
US20150336858A1 (en) * 2013-01-16 2015-11-26 Basf Se Method for producing acetylenes and syngas
US9580312B2 (en) * 2013-01-16 2017-02-28 Basf Se Method for producing acetylenes and syngas
CN104918879B (zh) * 2013-01-16 2017-07-14 巴斯夫欧洲公司 生产乙炔和合成气的方法
RU2648327C2 (ru) * 2013-01-16 2018-03-23 Басф Се Способ получения ацетилена и синтез-газа
US9802875B2 (en) 2013-08-29 2017-10-31 Basf Se Apparatus and process for preparing acetylene and synthesis gas

Also Published As

Publication number Publication date
JPS5238002B2 (enrdf_load_stackoverflow) 1977-09-27
BR7301095D0 (pt) 1973-11-01
NL7301998A (enrdf_load_stackoverflow) 1973-08-16
JPS4891001A (enrdf_load_stackoverflow) 1973-11-27
FR2172148A1 (enrdf_load_stackoverflow) 1973-09-28
IT979033B (it) 1974-09-30
DE2307300A1 (de) 1973-08-23
BE795403A (fr) 1973-08-14
FR2172148B1 (enrdf_load_stackoverflow) 1976-11-05

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