EP0100198A1 - Pech aus mit Dampf gecracktem Teer - Google Patents

Pech aus mit Dampf gecracktem Teer Download PDF

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Publication number
EP0100198A1
EP0100198A1 EP83304180A EP83304180A EP0100198A1 EP 0100198 A1 EP0100198 A1 EP 0100198A1 EP 83304180 A EP83304180 A EP 83304180A EP 83304180 A EP83304180 A EP 83304180A EP 0100198 A1 EP0100198 A1 EP 0100198A1
Authority
EP
European Patent Office
Prior art keywords
pitch
fraction
spinning
carbon fibers
steam cracker
Prior art date
Legal status (The legal status 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 status listed.)
Withdrawn
Application number
EP83304180A
Other languages
English (en)
French (fr)
Inventor
Ghazi Dickakian
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
EIDP Inc
Original Assignee
EI Du Pont de Nemours and Co
Exxon Research and Engineering Co
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
Application filed by EI Du Pont de Nemours and Co, Exxon Research and Engineering Co filed Critical EI Du Pont de Nemours and Co
Publication of EP0100198A1 publication Critical patent/EP0100198A1/de
Withdrawn legal-status Critical Current

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Classifications

    • D—TEXTILES; PAPER
    • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
    • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
    • D01F9/00—Artificial filaments or the like of other substances; Manufacture thereof; Apparatus specially adapted for the manufacture of carbon filaments
    • D01F9/08—Artificial filaments or the like of other substances; Manufacture thereof; Apparatus specially adapted for the manufacture of carbon filaments of inorganic material
    • D01F9/12—Carbon filaments; Apparatus specially adapted for the manufacture thereof
    • D01F9/14—Carbon filaments; Apparatus specially adapted for the manufacture thereof by decomposition of organic filaments
    • D01F9/145—Carbon filaments; Apparatus specially adapted for the manufacture thereof by decomposition of organic filaments from pitch or distillation residues
    • D01F9/155—Carbon filaments; Apparatus specially adapted for the manufacture thereof by decomposition of organic filaments from pitch or distillation residues from petroleum pitch
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10C—WORKING-UP PITCH, ASPHALT, BITUMEN, TAR; PYROLIGNEOUS ACID
    • C10C3/00—Working-up pitch, asphalt, bitumen

Definitions

  • This invention pertains to an aromatic pitch containing a high liquid crystal (optically active) fraction, and more particularly to a pitch which can be directly spun into carbon fibers.
  • mesophase structurally ordered optically anisotropic spherical liquid crystal
  • mesophase structurally ordered optically anisotropic spherical liquid crystal
  • suitable feedstocks for carbon artifact manufacture, and in particular carbon fiber manufacture should have relatively low softening points and sufficient viscosity suitable for shaping and spinning into desirable articles and fibers.
  • feedstock for carbon artifact manufacture Another important characteristic of the feedstock for carbon artifact manufacture is its rate of conversion to a suitable optically anisotropic material.
  • 350°C is the minimum temperature generally required to produce mesophase from a carbonaceous pitch.
  • at least one week of heating is necessary to produce a mesophase content of about 40%, at that minimum temperature.
  • Mesophase of course, can be generated in shorter times by heating at higher temperatures.
  • incipient coking and other undesirable side reactions take place at temperatures in excess of about 425°C.
  • Cat cracker bottoms like all other heavy aromatic residues obtained from steam cracking, fluid cracking or coal processing are composed of two components: (1) a low molecular weight oil fraction which can be distilled; and (2) an undistillable fraction of high molecular weight.
  • This high molecular weight fraction is insoluble in paraffinic solvents such as n-heptane, iso-octane, pet ether, etc. This fraction is generally called "asphaltene".
  • asphaltene-free feed for the production of pitches.
  • These asphaltenes have a very high molecular weight (up to 10,000), a very high coking characteristic (coking value as high as 67.5 wt% coke yield at 550°C)., and a very high melting point (200-250°C).
  • asphaltene-free cat cracker bottom is free of ash, coke particles and other impurities.
  • the absence of asphaltene, ash, coke particles and other organic and inorganic impurities make the cat cracker bottom distillate an ideal feed for the production of an aromatic pitch with a very high content of liquid crystals.
  • This asphaltene-free cat cracker bottom can be prepared by two methods: (a) by a distillation process; e.g., vacuum or steam distillation; and (b) by deasphaltenation of the cat cracker bottom.
  • the deasphaltenation can be made readily by solvent extraction with a paraffinic solvent.
  • the present invention uses deasphaltenated feedstock fractions to provide a pitch having a high Ti content, and one which does not require Ti solvent extraction prior to spinning into fibers.
  • the deasphaltenated fractions of a feedstock in accordance with this invention is generally free of ash and impurities, and has the proper rheological properties to allow direct spinning into carbon fibers.
  • the pitch obtained from this fraction produces fibers which have high strength and performance.
  • a deasphaltenated cat cracker bottom fraction obtained in accordance with the present invention has virtually no coking value at 550°C compared with a 56% standard coking value for Ashland 240.
  • the deasphaltenated cat cracker bottom fraction is composed of 4, 5, and 6 polycondensed aromatic rings. This provides a uniform feed material which can be carefully controlled to produce a uniform product with a narrow molecular weight distribution.
  • the present invention pertains to a high Ti pitch for direct spinning into carbon fibers.
  • An aromatic pitch with a very high liquid crystal fraction (80-100%) can be prepared by thermally reacting a deasphaltenated fraction of either a cat cracker bottom, steam cracker tar or a coal distillate, that are respectively rich in (4, 5 and 6); (2, 3, 4 and 5); and (3, 4, 5 and 6) aromatic rings.
  • the various feedstocks are heat soaked in a temperature range from 420°C to 450°C at atmospheric pressure, and then vacuum stripped to remove at least a portion of the unreacted oils at a temperature in the approximate. range of from 320°C to 420°C at 0.1 to 100 mmHg, and preferably at greater than 400°C at 5.0 mmHg of pressure.
  • the fraction in the case of cat cracker bottoms the fraction is heat soaked at approximately 440°C for 2-4 hours at atmospheric pressure. In the case of steam cracker tars, the fraction is heat soaked at 430 o C for approximately 40 hours; and in the case of coal distillate, the fraction is heat soaked at approximately 440°C for 1/4 to 1/2 hour. All the heat soaked materials are then vacuum stripped and spun directly into carbon fibers.
  • the pitch of this invention is definable only in terms of deasphaltenated fractions of a feedstock.
  • deasphaltenated feedstock and/or “deasphaltenated middle fraction of a feedstock” shall mean: a deasphaltenated material obtained from a middle cut of a feedstock, and/or one caused to be relatively free of asphaltenes by means of obtaining a distillate portion of said feedstock which when further treated will form a precursor which can be spun into a carbon fiber and which has the following general characteristics:
  • a typical weight percentage of asphaltenes in a deasphaltenated stream cracker tar being in a range of approximately 0.5 to 2.0%.
  • a directly spinnable pitch of this invention has the proper rheological properties characterized by a glass transition temperature (Tg) in the approximate range of 180°C to 250 o C at atmospheric pressure, and/or a viscosity of less than approximately 2,500 cps in a temperature range of approximately 300°C, to 360°C, at atmospheric pressure.
  • Tg glass transition temperature
  • the steam cracker tar which is used as a starting material in the process of the present invention is defined as the bottoms product obtained by cracking gas oils, particularly virgin gas oils, such as naphtha, at temperatures of from about 700°C to about 1000°C.
  • the tar is obtained as a bottoms product.
  • a gas oil is, of course, a liquid petroleum distillate with a viscosity and boiling range between kerosene and lubricating oil, and having a boiling range between about 200 o C and 400 o C.
  • Naphtha is a generic term for a refined, partly refined or unrefined liquid petroleum product of natural gas wherein not less than 10% distills below 175°c and not less than 95% distills below 240°C, as determined by ASTM Method D-86.
  • Steam cracker tars typically consist of alkyl substituted polycondensed aromatic compounds.
  • the steam cracker tars are distilled by heating to elevated temperatures at reduced pressures.
  • the stream cracker tar is heated to temperatures in the range of 130 o C to 320°C at an approximate pressure of 10 mm of mercury.
  • the steam cracker tar is separated into a middle distillate fraction having a boiling point at 760 mm mercury in the range of from about 270°C to about 490°C.
  • the distillate fraction of the steam cracker tar which is employed in forming a suitable carbonaceous pitch for carbon artifact manufacture is that fraction boiling in the range of about 370° to about 490°C at 760 mm of mercury.
  • the middle fraction distillate taken at 370-490°c @ 760 mmHg has high aromaticity and narrow molecular weight. It contains no ash or solid particulate and does not contain high coking asphaltene. Chemically it is composed of polycondensed 2, 3, 4 and 5 aromatic rings. Table 3 below gives the physical and chemical characteristics of a typical middle distillate fraction of a steam cracker tar:
  • Another method to prepare an asphaltene-free steam cracker tar fraction is by removing the asphaltene from steam cracker tar by a solvent extraction of the asphaltene with a paraffinic solvent such as n-heptane, iso-octane, n-pentene, or pet-ether.
  • a paraffinic solvent such as n-heptane, iso-octane, n-pentene, or pet-ether.
  • the middle fraction distillate is heat soaked at temperatures of about 430 o C at atmospheric pressure. In general, heat soaking is conducted for about-forty (40) hours. In the practice of the present invention, it is particularly preferred that heat soaking be done in an atmosphere such as nitrogen, or alternatively in hydrogen atmosphere.
  • the heat soaked distillate is then heated in a vacuum at temperatures generally about 400°C and typically in the range of about 370°C to 420°C, at pressures below atmospheric pressure, generally in the range of about 1.0 to 100 mm mercury. This additional heating removes at least part of the oil present in the heat soaked distillate. Typically, from about 90 to 100% of the oil which is present in the heat soaked distillate is removed.
  • the severity of the heat soaking conditions outlined above will affect the nature of the pitch produced. The higher the temperature chosen for heat soaking, and the longer the duration of the heat soaking process, the greater the amount of toluene insoluble components that will be generated in the pitch.
  • the inventive process can prepare pitches with a very high toluene insolubles content (80-100% by weight), and one which can be spun directly into carbon fibers, as shown in Figure 1.
  • the pitch of this invention si definable in terms of deasphaltenated fractions of a feedstock ( Figure 1).
  • pitches used for direct spinning are of great importance to obtain good spinnability. It is desired to have pitches with low viscosity at the spinning temperature which is prefer- rably below around 400°C, in order to avoid pitch cracking and volatilization which could lead to serious foaming of the fiber and substantial reduction in the fiber strength.
  • the pitch for direct spinning is also desired to be less sensitive to heat, i.e. does not change its viscosity too much when changing temperature. The sensitivity of the pitch to temperature variation can be determined from viscosity - temperature curves.
  • Differential Scanning Calorimetry is used to obtain information on glass transition and softening characteristics of pitches.
  • An OMINITHERM Corp. DSC Model (QC25) is used to obtain the glass transition (Tg) data.
  • the method comprises heating a small sample of the pitch in the DSC pan, allowed to cool and the DSC trace was then obtained by heating at the rate of 10 0 C/min under nitrogen (30cc/min). From the DSC trace three DSC data points are determined; the onset of Tg (Ti), the termination of Tg (Tf), and the Tg point which is at the midway between the Ti and Tf point. It has been reported that there is a relationship between the Tg of the pitch and its softening point as determined by the traditional method such as the ring and ball method. The softening point is higher by around 60°C than the Tg.
  • Figure 2 depicts a glass transition temperature scan for Example B in Table 7 above.
  • Table 8 illustrates glass transition temperatures for the previous examples A-D (Table 7):

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Civil Engineering (AREA)
  • Structural Engineering (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Textile Engineering (AREA)
  • Inorganic Fibers (AREA)
  • Working-Up Tar And Pitch (AREA)
EP83304180A 1982-07-19 1983-07-19 Pech aus mit Dampf gecracktem Teer Withdrawn EP0100198A1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US39975182A 1982-07-19 1982-07-19
US399751 1982-07-19

Publications (1)

Publication Number Publication Date
EP0100198A1 true EP0100198A1 (de) 1984-02-08

Family

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Family Applications (1)

Application Number Title Priority Date Filing Date
EP83304180A Withdrawn EP0100198A1 (de) 1982-07-19 1983-07-19 Pech aus mit Dampf gecracktem Teer

Country Status (4)

Country Link
EP (1) EP0100198A1 (de)
JP (1) JPS5933385A (de)
AU (1) AU558404B2 (de)
CA (1) CA1199758A (de)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2008027139A1 (en) * 2006-08-31 2008-03-06 Exxonmobil Chemical Patents Inc. Method for upgrading steam cracker tar using pox /cocker
US7846324B2 (en) 2007-03-02 2010-12-07 Exxonmobil Chemical Patents Inc. Use of heat exchanger in a process to deasphalt tar
US8083930B2 (en) 2006-08-31 2011-12-27 Exxonmobil Chemical Patents Inc. VPS tar separation
US8709233B2 (en) 2006-08-31 2014-04-29 Exxonmobil Chemical Patents Inc. Disposition of steam cracked tar

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5982417A (ja) * 1982-11-04 1984-05-12 Mitsubishi Oil Co Ltd 炭素繊維原料ピッチの製造方法
JPS61148244U (de) * 1985-03-02 1986-09-12
EP4209569A4 (de) * 2020-09-03 2024-09-11 Resonac Corporation Verfahren zur herstellung von pech

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4086156A (en) * 1974-12-13 1978-04-25 Exxon Research & Engineering Co. Pitch bonded carbon electrode
GB2020310A (en) * 1978-05-05 1979-11-14 Exxon Research Engineering Co Carbonaceous pitches
US4208267A (en) * 1977-07-08 1980-06-17 Exxon Research & Engineering Co. Forming optically anisotropic pitches
US4219404A (en) * 1979-06-14 1980-08-26 Exxon Research & Engineering Co. Vacuum or steam stripping aromatic oils from petroleum pitch
US4271006A (en) * 1980-04-23 1981-06-02 Exxon Research And Engineering Company Process for production of carbon artifact precursor
US4363715A (en) * 1981-01-14 1982-12-14 Exxon Research And Engineering Co. Production of carbon artifact precursors
EP0087749A1 (de) * 1982-02-23 1983-09-07 Mitsubishi Oil Company, Limited Pech als Rohstoff zur Herstellung von Kohlenstoffäden und Verfahren zur Herstellung derselben

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4086156A (en) * 1974-12-13 1978-04-25 Exxon Research & Engineering Co. Pitch bonded carbon electrode
US4208267A (en) * 1977-07-08 1980-06-17 Exxon Research & Engineering Co. Forming optically anisotropic pitches
GB2020310A (en) * 1978-05-05 1979-11-14 Exxon Research Engineering Co Carbonaceous pitches
US4219404A (en) * 1979-06-14 1980-08-26 Exxon Research & Engineering Co. Vacuum or steam stripping aromatic oils from petroleum pitch
US4271006A (en) * 1980-04-23 1981-06-02 Exxon Research And Engineering Company Process for production of carbon artifact precursor
US4363715A (en) * 1981-01-14 1982-12-14 Exxon Research And Engineering Co. Production of carbon artifact precursors
EP0087749A1 (de) * 1982-02-23 1983-09-07 Mitsubishi Oil Company, Limited Pech als Rohstoff zur Herstellung von Kohlenstoffäden und Verfahren zur Herstellung derselben

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2008027139A1 (en) * 2006-08-31 2008-03-06 Exxonmobil Chemical Patents Inc. Method for upgrading steam cracker tar using pox /cocker
US8083931B2 (en) 2006-08-31 2011-12-27 Exxonmobil Chemical Patents Inc. Upgrading of tar using POX/coker
US8083930B2 (en) 2006-08-31 2011-12-27 Exxonmobil Chemical Patents Inc. VPS tar separation
US8709233B2 (en) 2006-08-31 2014-04-29 Exxonmobil Chemical Patents Inc. Disposition of steam cracked tar
US7846324B2 (en) 2007-03-02 2010-12-07 Exxonmobil Chemical Patents Inc. Use of heat exchanger in a process to deasphalt tar

Also Published As

Publication number Publication date
AU558404B2 (en) 1987-01-29
AU1695483A (en) 1984-01-26
CA1199758A (en) 1986-01-28
JPS5933385A (ja) 1984-02-23

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PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

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Effective date: 19880131

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Inventor name: DICKAKIAN, GHAZI