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WO1997016507A1 - Procede de reduction de la formation de depots de carbone - Google Patents

Procede de reduction de la formation de depots de carbone Download PDF

Info

Publication number
WO1997016507A1
WO1997016507A1 PCT/EP1996/004728 EP9604728W WO9716507A1 WO 1997016507 A1 WO1997016507 A1 WO 1997016507A1 EP 9604728 W EP9604728 W EP 9604728W WO 9716507 A1 WO9716507 A1 WO 9716507A1
Authority
WO
WIPO (PCT)
Prior art keywords
diffusion annealing
carried out
enrichment
atmosphere
plants
Prior art date
Application number
PCT/EP1996/004728
Other languages
English (en)
Inventor
Henricus Matthias Woerde
Gerhard Zimmermann
Claudin Steurbaut
Fritz R. Van Buren
Robertus Joannes Nicolaas Gommans
John J. Jones
Original Assignee
K.T.I. Group B.V.
Dsm N.V.
Dow Benelux N.V.
Paralloy Ltd.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from DE19542219A external-priority patent/DE19542219C2/de
Application filed by K.T.I. Group B.V., Dsm N.V., Dow Benelux N.V., Paralloy Ltd. filed Critical K.T.I. Group B.V.
Priority to AU74962/96A priority Critical patent/AU719778B2/en
Priority to KR1019980703087A priority patent/KR19990067141A/ko
Priority to DE69606654T priority patent/DE69606654D1/de
Priority to AT96937304T priority patent/ATE189693T1/de
Priority to EP96937304A priority patent/EP0858494B1/fr
Priority to JP9517072A priority patent/JPH11514681A/ja
Publication of WO1997016507A1 publication Critical patent/WO1997016507A1/fr
Priority to NO981943A priority patent/NO981943D0/no

Links

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
    • C10G9/14—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
    • 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
    • C10G9/18—Apparatus
    • C10G9/20—Tube furnaces
    • 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
    • C10G9/18—Apparatus
    • C10G9/20—Tube furnaces
    • C10G9/203—Tube furnaces chemical composition of the tubes

Definitions

  • the invention relates to a process for reducing the catalytically induced formation of carbon deposits (catalytical coking) on the surfaces of components designed as heat exchangers, containers or conduits and made of a heat-resistant material that consists of an alloy containing Cr and at least one of the two elements Fe and Ni, whereas the components are designated to be exposed to hot process gases in process plants for producing chemical substances, especially plants for converting hydrocarbons, for example, or other substances containing C, by means of thermal or catalytic cracking (e.g., for converting ethylene dichloride into vinyl chloride) or plants for producing a CO-rich reduction gas, wherein an Al-enrichment in the surface reg on is carried out by means of diffusion annealing in an atmosphere containing Al.
  • thermal or catalytic cracking e.g., for converting ethylene dichloride into vinyl chloride
  • CO-rich reduction gas e.g., for converting ethylene dichloride into vinyl chloride
  • the object of the invention is, firstly, to suggest an altemative process for reducing the tendency to catalytic coking in components of a process plant for producing chemical substances (raw materials for further processing and end products) and, secondly, to suggest components with a reduced catalytic coking tendency.
  • an alternative process for producing chemical substances is to be suggested in which the tendency to catalytic coking of the components is reduced.
  • This object is attained in a process for reducing the catalytically induced formation of carbon deposits (catalytic coking) on the surfaces of components designed as heat exchangers, containers or conduits and made of a heat-resistant material that consists of a heat-resistant alloy containing Cr and at least one of the two elements Fe and Ni, whereby the components during operation time are exposed to hot C containing process gases in plants for producing chemical substances, especially in plants for converting, e.g.
  • hydrocarbons or other C containing substances by thermal or catalytic cracking or in plants for producing a CO-rich reduction gas, wherein an Al-enrichment is carried out on the surface region of the components by means of diffusion annealing in an atmosphere containing Al, by virtue of the fact that the diffusion annealing takes place in the temperature range of 900 to 1200 °C at least for a part of the annealing time in an atmosphere containing Cr and sufficiently long as to achieve a Cr- enrichment with a penetration depth of at least 20 ⁇ m.
  • a metal component according to the invention especially being designed as heat exchanger or container or conduit for a process plant for producing chemical substances and made of a heat-resistant base material that contains Cr and at least one of the two elements Fe and Ni, is achievable by the aforementioned process, whereas an Al-enrichment in those regions of its surface, which during production of the chemical substances are exposed to a hot process medium containing C, is effected by means of diffusion annealing in an atmosphere containing Al.
  • Such metal component is characterized by the fact that the diffusion annealing was carried out in the temperature range of 900 to 1200 °C and at least for a part of the annealing time in an atmosphere containing Cr and sufficiently long as to achieve a Cr-enrichment with a penetration depth of at least 20 ⁇ m.
  • the diffusion annealing (which is known per se) for enriching the surface regions in question with inhibiting substances should be undertaken in two steps.
  • the diffusion annealing is carried out at a temperature within the range of approximately 900 to 1200 °C.
  • the annealing is carried out in a first step in an atmosphere containing Cr, so Cr diffuses into the base material from the outside.
  • the duration of this diffusion annealing is calculated as to achieve a penetration depth of at least 20 ⁇ m for the Cr-enrichment.
  • a further diffusion annealing is carried out in an atmosphere containing Al.
  • this lasts at least until a penetration depth of 20 ⁇ m, and especially of 50 ⁇ m, is achieved for the Al-enrichment.
  • Penetration depths of at least 30 ⁇ m for Cr and at least 100 - 150 ⁇ m for Al have proved to be especially advantageous. Especially good results can be achieved at penetration depth up to 200 ⁇ m.
  • greater values are technically possible, they are not advantageous, especially for reasons of cost, because they provide no improved effect. It is advisable to carry out the two diffusion annealing steps in the two-step manner in the described order, so no unwanted unevenness in respect to the distribution of the diffused Cr and Al atoms in the surface regions occurs.
  • a process according to the invention for producing chemical substances through thermal or catalytic cracking or steam reforming of hydrocarbons or through other conversion of feedstock material containing C is characterized by the fact that the production ist undertaken in a process plant that contains at least one part designed as a heat exchanger (e.g. cracking tube), container or conduit, which was treated by diffusion annealing in the above-described manner in those regions of its surface which are exposed to the hot C containing process gases, wheras such diffusion annealing has effected a Cr and Al-enrichment in the surface region by means of diffusion of Cr and Al into the base material.
  • a process in particular, may be a thermal or catalytic cracking process for hydrocarbons or other carbon-containing substances (e.g. conversion of ethylene dichloride into vinyl chloride or for conversion of naphtha into light hydrocarbons), a process for producing a reduction gas rich in CO or a process for steam reforming of hydrocarbons.
  • the enrichment of Cr and Al in the surface layer of heat exchangers, containers or conduits of process plants achieved by means of diffusion annealing according to the invention provides, compared to a corresponding treatment of the surface alone with Cr or alone with Al, a better result in respect to prevention of catalytic coking.
  • a diffusion annealing e.g. in a Cr atmosphere alone, does indeed produce good inhibition on the surface shortly after such treatment; however, after several operation cycles, this effect is reduced drastically, and then even poorer results are obtained than with an untreated surface.
  • a significant advantage of the invention is the long- lastingness of the protective effect, even when the components treated according to the invention are exposed to high temperatures.
  • the inhibiting effect declines drastically by decoking at 1100 °C after a total decoking time of only 100 hours; however, this ist not the case with the invention.
  • the surface layer enriched with Al and Cr according to the invention have proved to be extraordinarily long-lasting under normal operating conditions.
  • the sample sheet was subjected to a two-step diffusion annealing in an annealing furnace.
  • the first step which lasted for approximately 6 hours, the sample sheet was exposed at approximately 1100 °C to an atmosphere containing Cr.
  • the Cr containing atmosphere was prepared by introducing Cr compounds into the furnace, decomposition of the compounds at the given annealing temperature and releasing elementary Cr.
  • a second annealing step following directly after the first step and carried out at a lower temperature, c. 950 °C, the sample sheet was exposed for 6 hours to an atmosphere containing Al, prepared in a corresponding manner.
  • an enrichment of the Cr content up to c. 55 % to a depth of c. 35 ⁇ m and an enrichment of the Al content to c. 30 % up to a depth of c. 150 ⁇ m had occured, whereby the Ni content of the Cr-enriched diffusion layer dropped below 3 %.
  • the treated and the untreated sample sheets were first subjected to a surface activation treatment for achieving in the subsequent test a tilltime-lapse effect," i.e., a shortening of the test periods for clearly determinable coking.
  • both sample sheets were annealed for 5 hours at 970 ⁇ C in an N 2 atmosphere. After this, the heat treatment was continued for 1 hour at 850 °C in an H 2 atmosphere (H 2 supply 6 Nl/h).
  • H 2 supply 6 Nl/h H 2 supply 6 Nl/h
  • the sheet was exposed for varying durations at 850 °C to a process gas atmosphere consisting of isobutane and N 2 (weight ratio of 2:1). This revealed a clear reduction in the catalytically induced carbon deposits on the surface exposed to the process gas, in comparison to the sample sheet of the same material that was similarly activated but had not been treated according to the invention.
  • the carbon deposits were measured by means of a thermal scale. The results are given in Table 1.
  • Example 2 Prior to the tests the same activation treatment as in Example 1 was carried out, so standard conditions existed. The results are shown in Table 2. In contrast to the untreated sample sheet, which displayed an increasing coking tendency (known, for example, from Oil & Gas Journal, August 15, 1988, page 70) at later cycles, the coking rate of the treated sample sheet remained essentially constant, and at a very low rate.
  • a sample sheet treated according to the invention as in Example 1 was tested in a tube furnace in comparison to an untreated sample sheet of the same material.
  • both the sample sheet treated according to the invention and the untreated sample sheet were first exposed for 90 minutes at 820°C to an atmosphere of 22.5 % by volume ethane, 27.5 % by volume ethylene and 50 % by volume H 2 and then decoked at 800°C in air for 30 minutes. After this, the coking rate was measured during a 3-hour exposure, again at 820°C, in the aforementioned ethane/ethylene/H 2 atmosphere.
  • the untreated sample sheet the coking rate was 16.0 ⁇ g/cm 2 min, while the sample sheet treated according to the invention hat a substantially lower coking rate of only 0.6 ⁇ g/cm 2 min.
  • Example 1 A sample sheet with the same composition as in Example 1 and with the dimensions 20 x 15 x 5 mm was exposed, under conditions corresponding to those in Example 1 , to a diffusion annealing; however, in an atmosphere containing Ai alone.
  • an untreated comparison sheet of the same composition and form was provided. In order to activate the surface, both sheets were exposed for 90 minutes at 820°C to an atmosphere which hat the same composition as the ethane/ethylene/H 2 atmosphere in Example 3, and then decoked in air for 60 minutes at 800°C. After this, the coking rates of the sample sheets prepared in this manner were measured during a coking treatment by a 2-hour exposure in the aforementioned ethane/ethylene/H 2 atmosphere, again at 820°C.
  • Example 3 the coking rate of the treated sample sheet was in fact less than 4 % of the coking rate of the untreated sample sheet. This shows clearly the surprisingly high effectiveness of the invention.

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  • Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Thermal Sciences (AREA)
  • Organic Chemistry (AREA)
  • Catalysts (AREA)
  • Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)
  • Carbon And Carbon Compounds (AREA)
  • Solid-Phase Diffusion Into Metallic Material Surfaces (AREA)
  • Physical Or Chemical Processes And Apparatus (AREA)

Abstract

L'invention concerne un procédé de réduction de la formation de dépôts de carbone (carbonisation) induits de manière catalytique sur les surfaces d'éléments conçus en tant qu'échangeurs de chaleur, conduits ou contenants et réalisés dans un matériau thermorésistant consistant en un alliage thermorésistant contenant Cr ainsi que l'un au moins des deux éléments Fe et Ni, lorsque ces éléments sont exposés à des gaz chauds de processus carbonés dans des installations de traitement destinées à produire des substances chimiques, notamment des installations destinées à convertir des hydrocarbures ou autres substances contenant C au moyen d'un craquage thermique ou catalytique ou au moyen d'un reformage à la vapeur, ou des installations destinées à produire un gaz de réduction riche en CO. Le procédé de réduction selon l'invention consiste à effectuer un enrichissement en Al, sur la région superficielle des éléments, à l'aide d'un recuit d'homogénéisation et dans une atmosphère contenant Al. Le processus du recuit d'homogénéisation s'effectue dans une plage de températures se situant entre 900 et 1200 °C, au moins pendant une partie du temps de traitement dans une atmosphère contenant Cr, jusqu'à l'obtention d'un enrichissement en Cr présentant une profondeur de pénétration d'au moins 20 νm.
PCT/EP1996/004728 1995-10-31 1996-10-31 Procede de reduction de la formation de depots de carbone WO1997016507A1 (fr)

Priority Applications (7)

Application Number Priority Date Filing Date Title
AU74962/96A AU719778B2 (en) 1995-10-31 1996-10-31 Process for reducing the formation of carbon deposits
KR1019980703087A KR19990067141A (ko) 1995-10-31 1996-10-31 카본 디포짓 형성의 저감 프로세스
DE69606654T DE69606654D1 (de) 1995-10-31 1996-10-31 Verfahren zur verringerung von kohlenstoffablagerungen, metallischer stoff und verfahren zur herstellung von chemischen substanzen
AT96937304T ATE189693T1 (de) 1995-10-31 1996-10-31 Verfahren zur verringerung von kohlenstoffablagerungen, metallischer stoff und verfahren zur herstellung von chemischen substanzen
EP96937304A EP0858494B1 (fr) 1995-10-31 1996-10-31 Procede de reduction de la formation de depots de carbone, compose metallique et procede de production de produits chimiques
JP9517072A JPH11514681A (ja) 1995-10-31 1996-10-31 炭素付着物の生成を減少させる方法
NO981943A NO981943D0 (no) 1995-10-31 1998-04-29 FremgangsmÕte for reduksjon av karbonavsetninger

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
DE19542219.8 1995-10-31
DE19542219A DE19542219C2 (de) 1995-10-31 1995-10-31 Verfahren zur Verminderung der Bildung von Kohlenstoffablagerungen
US1140196P 1996-02-09 1996-02-09
US60/011,401 1996-02-09

Publications (1)

Publication Number Publication Date
WO1997016507A1 true WO1997016507A1 (fr) 1997-05-09

Family

ID=26020325

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP1996/004728 WO1997016507A1 (fr) 1995-10-31 1996-10-31 Procede de reduction de la formation de depots de carbone

Country Status (11)

Country Link
EP (1) EP0858494B1 (fr)
JP (1) JPH11514681A (fr)
KR (1) KR19990067141A (fr)
CN (1) CN1201480A (fr)
AT (1) ATE189693T1 (fr)
AU (1) AU719778B2 (fr)
CA (1) CA2236091A1 (fr)
HU (1) HUP9900820A3 (fr)
NO (1) NO981943D0 (fr)
PL (1) PL326370A1 (fr)
WO (1) WO1997016507A1 (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1998007806A1 (fr) * 1996-08-23 1998-02-26 Alon, Inc. Tubes-foyers a revetement applique par diffusion, pour production d'ethylene
EP0889146A1 (fr) * 1997-07-04 1999-01-07 Institut Français du Pétrole Acier réfractaire chromisé, son procédé d'obtention et ses utilisations dans des applications anti-cokage
US6537388B1 (en) 1996-08-23 2003-03-25 Alon, Inc. Surface alloy system conversion for high temperature applications
WO2009036776A1 (fr) * 2007-09-13 2009-03-26 Siemens Aktiengesellschaft Produit sidérurgique résistant à la corrosion pour récipients sous pression, procédé pour sa fabrication, et élément de turbine à gaz

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE529444C2 (sv) * 2005-12-02 2007-08-14 Sandvik Intellectual Property Rör och användning av röret

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1995018849A1 (fr) * 1994-01-04 1995-07-13 Chevron Chemical Company Procedes de craquage

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1995018849A1 (fr) * 1994-01-04 1995-07-13 Chevron Chemical Company Procedes de craquage

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
ALBRIGHT ET AL: "Aluminized ethylene furnace tubes extend operating life", OIL AND GAS JOURNAL, 31 August 1987 (1987-08-31), TULSA, OKLAHOMA, pages 46 - 50, XP000616749 *

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1998007806A1 (fr) * 1996-08-23 1998-02-26 Alon, Inc. Tubes-foyers a revetement applique par diffusion, pour production d'ethylene
US6537388B1 (en) 1996-08-23 2003-03-25 Alon, Inc. Surface alloy system conversion for high temperature applications
EP0889146A1 (fr) * 1997-07-04 1999-01-07 Institut Français du Pétrole Acier réfractaire chromisé, son procédé d'obtention et ses utilisations dans des applications anti-cokage
FR2765594A1 (fr) * 1997-07-04 1999-01-08 Inst Francais Du Petrole Acier refractaire chromise, son procede d'obtention et ses utilisations dans des applications anti-cokage
US6348145B1 (en) 1997-07-04 2002-02-19 Institut Francais Du Petrole Chromized refractory steel, a process for its production and its uses in anti-coking applications
WO2009036776A1 (fr) * 2007-09-13 2009-03-26 Siemens Aktiengesellschaft Produit sidérurgique résistant à la corrosion pour récipients sous pression, procédé pour sa fabrication, et élément de turbine à gaz

Also Published As

Publication number Publication date
EP0858494A1 (fr) 1998-08-19
ATE189693T1 (de) 2000-02-15
HUP9900820A3 (en) 2001-02-28
KR19990067141A (ko) 1999-08-16
AU7496296A (en) 1997-05-22
AU719778B2 (en) 2000-05-18
NO981943L (no) 1998-04-29
CN1201480A (zh) 1998-12-09
PL326370A1 (en) 1998-09-14
NO981943D0 (no) 1998-04-29
EP0858494B1 (fr) 2000-02-09
HUP9900820A1 (hu) 1999-06-28
CA2236091A1 (fr) 1997-05-09
JPH11514681A (ja) 1999-12-14

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