WO1993002996A1 - Pyrolysis of naturally occuring cresylic acid mixtures - Google Patents
Pyrolysis of naturally occuring cresylic acid mixtures Download PDFInfo
- Publication number
- WO1993002996A1 WO1993002996A1 PCT/US1992/005763 US9205763W WO9302996A1 WO 1993002996 A1 WO1993002996 A1 WO 1993002996A1 US 9205763 W US9205763 W US 9205763W WO 9302996 A1 WO9302996 A1 WO 9302996A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- cresylic acid
- guaiacol
- pyrolysis
- stream
- temperature
- Prior art date
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C37/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring
- C07C37/68—Purification; separation; Use of additives, e.g. for stabilisation
- C07C37/70—Purification; separation; Use of additives, e.g. for stabilisation by physical treatment
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C37/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring
- C07C37/68—Purification; separation; Use of additives, e.g. for stabilisation
- C07C37/685—Processes comprising at least two steps in series
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C37/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring
- C07C37/68—Purification; separation; Use of additives, e.g. for stabilisation
- C07C37/86—Purification; separation; Use of additives, e.g. for stabilisation by treatment giving rise to a chemical modification
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C39/00—Compounds having at least one hydroxy or O-metal group bound to a carbon atom of a six-membered aromatic ring
- C07C39/02—Compounds having at least one hydroxy or O-metal group bound to a carbon atom of a six-membered aromatic ring monocyclic with no unsaturation outside the aromatic ring
- C07C39/06—Alkylated phenols
- C07C39/07—Alkylated phenols containing only methyl groups, e.g. cresols, xylenols
Definitions
- the present invention relates to a process for removing alkoxyaromatic impurities, particularly
- guaiacols from naturally occurring cresylic acid feeds by vapor phase pyrolysis.
- Cresylic acid is an important commercial product widely used in the manufacture of chemical, agrichemical, pharmaceutical and industrial intermediate products.
- the lowest molecular weight member of the cresylic acid family - phenol - is produced synthetically in very large
- cresylic acids recovered from these sources are heavily contaminated with aromatic organic compounds including hydrocarbons as well as those containing hetero-atoms such as nitrogen, sulfur and oxygen.
- Methoxy substituted phenols comprise a particularly troublesome group derived from some low grade coals such as brown coal or lignite. Guaiacol - methoxy phenol - boils near the boiling points of meta- and para-cresol and methyl guaiacols - methoxy cresols - boil in the range of the xylenols. Therefore, the guaiacol cannot be separated from the cresylic acid fractions by conventional distillation.
- cresylic acid must be separated from the other impurities and often from each other, and therein lies the problem because, heretofore there has been no simple process for physically separating guaiacols from cresylic acid. Therefore, the guaiacol must be destroyed in the presence of the cresylic acid which also presents a problem of cresylic acid yield loss.
- the crude cresylic acid mixture obtained from lignite contains larger amounts of guaiacol than the mixture obtained from coal, up to almost 4% by weight, or even more. Heretofore, such destruction has been accomplished only with difficulty and the resultant loss of cresylic acid yield to byproducts, most of them unwanted heavies and coke.
- the object of the present invention is to provide a process for the removal of guaiacol from crude cresylic acid feed streams.
- the present invention therefore provides a process for removing methoxyaromatic impurities from a vaporized feed stream of naturally occurring cresylic acid mixtures which comprises: passing the vaporized feed stream through a heated tubular reactor at a temperature of at least about 450°C at pyrolysis conditions to form a pyrolysis product stream, quenching the pyrolysis product stream to halt byproduct formation and condense cresylic acid, removing non-condensible gaseous compounds from the quenched pyrolysis product stream, and recovering the cresylic acid from such product stream.
- the present invention further provides a process for removing guaiacol from a naturally occurring cresylic acid mixture which comprises: filtering the cresylic acid mixture to remove pitch, distilling the mixture to remove phenol and impurities having low boiling points,
- cresylic acid mixture recycling from one-fourth to three-fourths of the cooled cresylic acid mixture to the condenser vessel, and recovering the rest of the cresylic acid.
- Fig. 1 is a schematic flow diagram of a preferred embodiment of this invention with common process
- Fig. 2 is a flow diagram, partially in schematic form, showing the test equipment used to perform the examples of this invention.
- This invention is the vapor phase pyrolysis of naturally occurring cresylic acid mixtures recovered from the pitch residual in removal of liquids from coal, coal tars, lignite or natural gas condensates.
- These naturally occurring cresylic acid-containing mixtures include several methoxyaromatic impurities, particularly guaiacol, which is often present in amounts up to about 4% and sometimes about 6% by weight, where the materials comes from a lignite source and about 2% where the cresylic acid mixture which forms the feed for the practice of this invention is recovered from coal, or a coal tar.
- the process of this invention would successfully operate to remove even greater amounts of guaiacols in naturally occurring feeds and should not be considered limited to one containing 4% by weight.
- the crude feed is usually treated to remove residual pitch and distilled to remove phenols and light low-boiling hydrocarbons; i.e., those materials which have boiling points below or near that of the phenol being removed.
- the feed is vaporized in any number of ways well-known to those skilled in the art and fed into a tubular reactor which is externally heated, much like steam in a boiler tube or in thermal cracking unit operations, such as in use for thermal cracking of naptha to obtain methylene in a boiler.
- the material preferably used for the tubular reactor would be steel, preferably stainless steel, such that the vapors flow smoothly through the zone being heated.
- the tubular reactor may optionally be packed with an inert packing such as beryl saddles, steel tower packing and the like to aid in uniform heat distribution.
- the tubular reactors may be oriented with the longitudinal axis either horizontal or vertical, as long as the heating is uniform.
- the reactor is operated at a temperature of at least about 450°C as long as the other conditions
- pressure and throughput result in pyrolysis conditions, satisfactorily at temperatures from about 475 - 625°C, preferably from about 500°C to about 600°C and most preferably from about 530°C to about 580°C.
- the pressure range for operating the pyrolysis of this process is from about atmospheric pressure to about four atmospheres, preferably about atmospheric pressure for cost considerations and product recovery. Operation of the pyrolysis process under slight pressure of from about 4 to about 12 psig had beneficial effects on
- guaiacol removal Operating under pressure significantly increases guaiacol removal while having little or no effect on gas production but would result in greater coke formation. This was the expected result since the
- residence time was increased by operating under pressure, (i.e., doubling the system pressure while maintaining constant mass flow rate would decrease the volumetric flow rate by one-half) allowing higher flow rates or lower operating temperatures to be used while achieving guaiacol removal similar to that obtained at atmospheric pressure.
- Equipment sizing in a commercial process might also be reduced by operating under pressure.
- Cresylic acid composition influenced guaiacol removal efficiency and byproducts. Byproduct formation was much more evident when using meta,para-cresol mixture as a feed than when full range acid feed was processed. Complete removal of guaiacol from dephenolized lignite based cresylic acid (4% guaiacol) was slightly more difficult to achieve than from meta, ⁇ ara-cresol mixtures spiked with guaiacol for test purposes or coal based feed. Meta,para-Cresol treated at 530°C and LHSV
- the quantity of off-gases and coke produced was proportional to the concentration of guaiacol in the feed. Comparing coal-based feed with lignite-based feed, doubling the guaiacol content in the feed more than dou led coke formation. Although the total quantity of off gases was also doubled, gas formation per pound of gua acol treated was the same for both feeds. Less gas was formed per pound of guaiacol when the source was rn,p cresol than from a full range acid feed. A slight quantity of coke and gas is produced from coal-based feed containing no guaiacol under pyrolysis conditions
- Water may be present in the cresylic acid feed stream as it is introduced into the reactor or added to the cresylic acid feed stream to inhibit coke formation even though its presence may inhibit guaiacol conversion slightly.
- 3% by weight or more of water may be present with the ultimate amount being determined by economic and commercial considerations with the preferred range from about 5 wt% to about 12 wt%.
- the feed enters a furnace 10 through a crude feed stream 12.
- the furnace 10 is fired with fuel, such as, for example, natural gas, entering in through lines 14 and 16 to burners (not shown). While any number of fuel points are commonly used, two are shown here for illustration, the fuel entering through line 14 warming a vaporization zone 18 where the crude feed entering through line 12 is vaporized.
- the vaporized crude cresylic acid stream containing guaiacol passes through the vaporization zone 18 through tubes 19 and exits through line 20 and proceeds to a knock-out drum 22 where the vaporized feed is
- the vapors exit the knock-out drum 22 through line 26 and re-enter the furnace 10 into the pyrolysis zone 28 where it passes through a tubular reactor 30 in the pyrolysis zone 28. It is here, operating at the pyrolysis conditions previously discussed, that the guaiacol and other methoxyaromatics are converted to pyrolysis reaction, or degradation, products.
- the pyrolyzed vapor stream leaves the pyrolysis zone 28 through line 32 where it enters a quench condenser 34.
- the pyrolysis products are contacted with quench stream, preferably cooled condensed cresylic acid entering the quench condenser 34 through line 36.
- Prompt quenching serves the primary purposes of halting all reactions occurring in the pyrolysis and liquefying the cresylic acid.
- Non-condensible gases such as, for example, carbon monoxide, methane and
- the amount of cooled cresylic acid mixture to be recycled may be readily calculated using the thermodynamic properties of the pyrolysis product stream readily available to the skilled engineer. Usually from about one-fourth to about three-fourths of the stream exiting the heat exchanger 42 will be recycled to the condenser 34. Preferably, from about 40% to 60% will be recycled, depending upon the thermodynamics of the stream.
- a treated product of cresylic acid, substantially free of the troublesome guaiacol, is bled from line 44 through line 46 and is carried thence to a storage tank for further processing for sale or use.
- the quench condenser 34 is operated at
- the quench is operated for the dual purpose to halt the pyrolysis reaction to prevent the formation of byproducts and reduction of cresylic acid yield which would otherwise be lost through the formation of a heavies stream.
- the treated product exiting through line 46 then may be more refined by flash distillation, not shown. Recovery of treated flash distillation
- Vapor phase pyrolysis of guaiacol tests were run in a 3/4" internal diameter X 28" long 316 stainless steel pipe reactor tube 110, shown schematically in Fig. 2.
- the pipe was packed with inert materials 112 (stainless steel packing, glass spheres, or MgO pellets) to paid heat transfer.
- a fluidized sand bath 114 held by an outer pipe 115 and heated by two 1500 watt nichrome heaters 116, in turn heated the reactor 110 and provided even
- Air to fluidize the sand bath entered through line 118 and was preheated to 500-600°C in a 1" X 12" pipe, packed with alloy 20 skived fibers, placed in a Lindberg tube furnace 119.
- Thermocouples 120 measured the sand temperature and reactor internal
- the feed stream 122 joined by an optional air or nitrogen diluent stream 123 were pumped into the reactor 110 with a MPL Series 2 micropump (not shown) at 100-300 ml/hour to perform the tests which are described later.
- the feed entering line 122 passed through heated sand 114 where the feed was vaporized.
- the top of the tubular reactor 110c was packed with alloy 20
- Residue was determined on selected composite samples by flashing at 100 mm Hg until the overhead temperature began to drop (generally ⁇ 165 °C). Residue remaining in the flask was weighted and reported as a percentage of the cresylics charged. Coke formation was calculated by weighing the reactor tube before and after the run, with any residual cresylic acid having been removed by a steam purge of the system. While the above described methods and apparatus were used to conduct the tests described in Examples I through IV which follow any comparable test procedures and instruments, known in the art are
- a mixture of m,p-cresol containing 4% guaiacol was a prepared and passed through a vaporizer assembly and tubular reactor packed with an inert material for heat transfer, as described above and shown in Fig. 2.
- the reactor in a fluidized sand bath was heated to 500-600°C and operated at atmospheric pressure.
- the cresylic acid flow corresponded to a LHSV of 0.6 - 1.7hr -1 .
- Coal-based cresylic acid containing ⁇ 4% guaiacol (added to form mixture) was passed through the reactor in the same way as in Example I at 530°C to give 0.02% unreacted guaiacol at 0.6%hr -1 LHSV and 0.18% guaiacol at 1.2hr -1 .
- Treating the coal-based cresylic acid feed at 550°C reduced guaiacol to trace levels at 0.6hr -1 and to ⁇ 0.01% at 1.2hr -1 .
- the quartz reactor configuration was similar to that of the stainless steel reactor described above.
- the reactor was operated as isothermal conditions to the condenser by wrapping with heat tape and using an additional temperature controller.
- the amount of catechol produced was higher at atmospheric pressure. At 25 psig, the amount of phenol produced was higher than at
- Methane and carbon monoxide were the predominant non-condensible gases.
- the rate of coke formation was determined to be 0.011 wt.% of the feed.
- meta-cresol was pyrolyzed in two stainless steel reactors at 500°C and atmospheric pressure and in a quartz
- pyrolysis is a simple, efficient method for removing guaiacol from lignite-based feed as well as the other naturally- occurring sources of cresylic acid.
- the advantages of the process of this invention can be achieved by adjusting operating conditions in accordance with the above
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)
Abstract
Description
Claims
Priority Applications (7)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP92914678A EP0597882B1 (en) | 1991-08-09 | 1992-07-09 | Pyrolysis of naturally occuring cresylic acid mixtures |
AU23106/92A AU662754B2 (en) | 1991-08-09 | 1992-07-09 | Pyrolysis of naturally occuring cresylic acid mixtures |
DE69211138T DE69211138T2 (en) | 1991-08-09 | 1992-07-09 | PYROLYSIS OF NATURALLY APPLICABLE CRESYLIC ACID MIXTURES |
PL92302349A PL169132B1 (en) | 1991-08-09 | 1992-07-09 | Method of removing in natural way methooxyaromatic impurities from cresylic acid mixtures |
KR1019940700441A KR940702151A (en) | 1991-08-09 | 1992-07-09 | Pyrolysis of naturally ccuring cresylio acid mixtures |
UA94005296A UA37193C2 (en) | 1991-08-09 | 1992-07-09 | method for purification of cresylic acid |
SK141-94A SK280080B6 (en) | 1991-08-09 | 1992-07-09 | Process of removing methoxyaromatic impurities from vapour phase of naturally occuring cresolic acid mixtures |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US07/743,077 US5146010A (en) | 1991-08-09 | 1991-08-09 | Pyrolysis of naturally occurring cresylic acid mixtures |
US743,077 | 1991-08-09 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1993002996A1 true WO1993002996A1 (en) | 1993-02-18 |
Family
ID=24987429
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US1992/005763 WO1993002996A1 (en) | 1991-08-09 | 1992-07-09 | Pyrolysis of naturally occuring cresylic acid mixtures |
Country Status (19)
Country | Link |
---|---|
US (1) | US5146010A (en) |
EP (1) | EP0597882B1 (en) |
JP (1) | JP3190433B2 (en) |
KR (2) | KR940702151A (en) |
AT (1) | ATE138632T1 (en) |
AU (1) | AU662754B2 (en) |
CA (1) | CA2070754C (en) |
CZ (1) | CZ282619B6 (en) |
DE (2) | DE4221598A1 (en) |
ES (1) | ES2090665T3 (en) |
FR (1) | FR2680170B1 (en) |
GB (1) | GB2258463B (en) |
GE (1) | GEP19991789B (en) |
PL (1) | PL169132B1 (en) |
SK (1) | SK280080B6 (en) |
TW (1) | TW204338B (en) |
UA (1) | UA37193C2 (en) |
WO (1) | WO1993002996A1 (en) |
ZA (1) | ZA924361B (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR20040019145A (en) * | 2002-08-26 | 2004-03-05 | 주식회사 이코바이오 | Natural Mouthwash Formulation |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5254750A (en) * | 1993-04-05 | 1993-10-19 | Merichem Company | Removal of guaiacol from cresylic acid by heating with a strong base |
JP5892277B2 (en) * | 2012-11-30 | 2016-03-23 | トヨタ自動車株式会社 | Catalyst for demethylation or demethoxylation reaction in a liquid phase of a mixture containing guaiacol as a main component, and method for producing phenol or catechol using the same |
Family Cites Families (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE204474C (en) * | ||||
US3375283A (en) * | 1965-07-29 | 1968-03-26 | Crown Zellerbach Corp | Preparation of methoxy phenols from spent pulping liquors |
US4208350A (en) * | 1978-03-06 | 1980-06-17 | Boise Cascade Corporation | Separating phenols from alkaline pulping spent liquors |
US4420642A (en) * | 1982-02-18 | 1983-12-13 | Fmc Corporation | Selective removal and recovery of catechol mixed with 2-methallyloxyphenol |
DD204474A1 (en) * | 1982-03-09 | 1983-11-30 | Leuna Werke Veb | REMOVAL OF GUAJACOL FROM CRESOL MIXTURES |
SU1235860A1 (en) * | 1984-12-10 | 1986-06-07 | Институт горючих ископаемых | Method of producing phenol and isopropylenebenzol |
JPS6479127A (en) * | 1987-09-21 | 1989-03-24 | Jgc Corp | Production of phenols from lignin |
-
1991
- 1991-08-09 US US07/743,077 patent/US5146010A/en not_active Expired - Lifetime
-
1992
- 1992-06-09 GB GB9212141A patent/GB2258463B/en not_active Expired - Lifetime
- 1992-06-09 CA CA002070754A patent/CA2070754C/en not_active Expired - Lifetime
- 1992-06-15 ZA ZA924361A patent/ZA924361B/en unknown
- 1992-06-30 TW TW081105187A patent/TW204338B/zh not_active IP Right Cessation
- 1992-07-01 DE DE4221598A patent/DE4221598A1/en not_active Withdrawn
- 1992-07-01 FR FR9208094A patent/FR2680170B1/en not_active Expired - Lifetime
- 1992-07-01 JP JP17455592A patent/JP3190433B2/en not_active Expired - Lifetime
- 1992-07-09 ES ES92914678T patent/ES2090665T3/en not_active Expired - Lifetime
- 1992-07-09 KR KR1019940700441A patent/KR940702151A/en not_active IP Right Cessation
- 1992-07-09 GE GEAP19922689A patent/GEP19991789B/en unknown
- 1992-07-09 AT AT92914678T patent/ATE138632T1/en not_active IP Right Cessation
- 1992-07-09 DE DE69211138T patent/DE69211138T2/en not_active Expired - Lifetime
- 1992-07-09 AU AU23106/92A patent/AU662754B2/en not_active Expired
- 1992-07-09 WO PCT/US1992/005763 patent/WO1993002996A1/en active IP Right Grant
- 1992-07-09 CZ CZ94256A patent/CZ282619B6/en not_active IP Right Cessation
- 1992-07-09 UA UA94005296A patent/UA37193C2/en unknown
- 1992-07-09 EP EP92914678A patent/EP0597882B1/en not_active Expired - Lifetime
- 1992-07-09 SK SK141-94A patent/SK280080B6/en not_active IP Right Cessation
- 1992-07-09 PL PL92302349A patent/PL169132B1/en unknown
- 1992-07-09 KR KR1019940700441A patent/KR0144110B1/en active
Non-Patent Citations (4)
Title |
---|
CHEMICAL ABSTRACTS, vol. 100, no. 23, 4 June 1984, Columbus, Ohio, US; abstract no. 191566E, W. HOERINGKLEE ET AL.: 'Separation of guaiacol from cresol mixtures.' page 552 ;column 2 ; * |
CHEMICAL ABSTRACTS, vol. 66, no. 9, 27 February 1965, Columbus, Ohio, US; abstract no. 37557A, Y.K. SHAPOSHNIKOV ET AL.: 'Pyrolysis of methyl ethers of pyrocatechol and pyrogallol.' page 3561 ;column 1 ; * |
CHEMICAL ABSTRACTS, vol. 77, no. 26, 25 December 1972, Columbus, Ohio, US; abstract no. 166403Y, A.N. KISLITSYN ET AL.: 'Thermal decomposition of guaiacol.' page 99 ;column 2 ; * |
See also references of EP0597882A1 * |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR20040019145A (en) * | 2002-08-26 | 2004-03-05 | 주식회사 이코바이오 | Natural Mouthwash Formulation |
Also Published As
Publication number | Publication date |
---|---|
ATE138632T1 (en) | 1996-06-15 |
CA2070754C (en) | 2002-02-26 |
DE69211138D1 (en) | 1996-07-04 |
GB9212141D0 (en) | 1992-07-22 |
US5146010A (en) | 1992-09-08 |
SK280080B6 (en) | 1999-07-12 |
SK14194A3 (en) | 1994-09-07 |
ES2090665T3 (en) | 1996-10-16 |
EP0597882B1 (en) | 1996-05-29 |
EP0597882A1 (en) | 1994-05-25 |
CZ25694A3 (en) | 1994-05-18 |
JP3190433B2 (en) | 2001-07-23 |
FR2680170B1 (en) | 1994-10-07 |
PL169132B1 (en) | 1996-06-28 |
GB2258463B (en) | 1995-04-05 |
KR940702151A (en) | 1994-07-28 |
UA37193C2 (en) | 2001-05-15 |
GB2258463A (en) | 1993-02-10 |
DE69211138T2 (en) | 1997-01-23 |
AU2310692A (en) | 1993-03-02 |
AU662754B2 (en) | 1995-09-14 |
DE4221598A1 (en) | 1993-02-18 |
GEP19991789B (en) | 1999-10-05 |
CA2070754A1 (en) | 1993-02-10 |
ZA924361B (en) | 1993-08-17 |
TW204338B (en) | 1993-04-21 |
JPH05201901A (en) | 1993-08-10 |
KR0144110B1 (en) | 1998-07-15 |
CZ282619B6 (en) | 1997-08-13 |
FR2680170A1 (en) | 1993-02-12 |
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