CA1092045A - Coal deashing process having improved solvent recovery techniques - Google Patents
Coal deashing process having improved solvent recovery techniquesInfo
- Publication number
- CA1092045A CA1092045A CA279,526A CA279526A CA1092045A CA 1092045 A CA1092045 A CA 1092045A CA 279526 A CA279526 A CA 279526A CA 1092045 A CA1092045 A CA 1092045A
- Authority
- CA
- Canada
- Prior art keywords
- dissolving solvent
- mixture
- zone
- mixing
- coal
- 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.)
- Expired
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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
- C10G1/00—Production of liquid hydrocarbon mixtures from oil-shale, oil-sand, or non-melting solid carbonaceous or similar materials, e.g. wood, coal
- C10G1/04—Production of liquid hydrocarbon mixtures from oil-shale, oil-sand, or non-melting solid carbonaceous or similar materials, e.g. wood, coal by extraction
-
- 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
- C10G1/00—Production of liquid hydrocarbon mixtures from oil-shale, oil-sand, or non-melting solid carbonaceous or similar materials, e.g. wood, coal
- C10G1/006—Combinations of processes provided in groups C10G1/02 - C10G1/08
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
- C10L9/00—Treating solid fuels to improve their combustion
- C10L9/02—Treating solid fuels to improve their combustion by chemical means
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Wood Science & Technology (AREA)
- Combustion & Propulsion (AREA)
- Solid Fuels And Fuel-Associated Substances (AREA)
- Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)
Abstract
A COAL DEASHING PROCESS HAVING
IMPROVED SOLVENT RECOVERY TECHNIQUES
Abstract of Disclosure An improved coal deashing process wherein coal is mixed with a first dissolving solvent, solubilized and flashed to provide a prepared mixture, and the prepared mixture is mixed with a second dissolving solvent to produce a feed mixture. The insoluble coal products produced are separated from the feed mixture as a first heavy fraction in a first separation zone and the soluble coal products are recovered as a second heavy fraction from a second separation zone. The second dissolving solvent is recovered from the first heavy fraction and the second heavy fraction for recycling to aid in the production of the feed mixture.
The first dissolving solvent is recovered from the first and the second heavy fractions and recycled to aid in solubilization of the coal.
IMPROVED SOLVENT RECOVERY TECHNIQUES
Abstract of Disclosure An improved coal deashing process wherein coal is mixed with a first dissolving solvent, solubilized and flashed to provide a prepared mixture, and the prepared mixture is mixed with a second dissolving solvent to produce a feed mixture. The insoluble coal products produced are separated from the feed mixture as a first heavy fraction in a first separation zone and the soluble coal products are recovered as a second heavy fraction from a second separation zone. The second dissolving solvent is recovered from the first heavy fraction and the second heavy fraction for recycling to aid in the production of the feed mixture.
The first dissolving solvent is recovered from the first and the second heavy fractions and recycled to aid in solubilization of the coal.
Description
The present invention relates generally to coal deashing processes and, more particularly, bu-t not by way of limitation, to improved solvent recovery systems in coal deashing processes.
Various coal deashing processes have been developed in the past wherein coal has been treated with one or more solvents and processed to separate the resulting insoluble coal products from the soluble coal products, some systems including provisions for recovering and recycling the solvents. For example, coal is contacted with a solvent and the resulting mixture then is separated into a heavy phase containing the insoluble coal products and a light phase containing the soluble coal products.
In such processes, the light phase is withdrawn and passed to downstream fractionating vessels wherein the soluble coal product is separated into multiple fractions.
The present invention provides a process comprising:
mixing in a first mixing zone a first dissolving solvent with coal solubilizing the coal, and flashing the resultant mixture to produce a prepared mixture comprising the first dissolving solvent, -~
20 the soluble coal products and the insoluble coal products; mixing ;
the prepared mixture with a second dissolving solvent to provide a feed mixture; introducing the feed mixture into a first separ-ation zone; separating the feed mixture in the first separation zone into a first heavy fraction comprising the insoluble coal products, some of the first dissolving solvent and some of the second dissolving solvent, and into a first light fraction; -flashing the first heavy fraction to produce one stream comprising the insoluble coal products and one other stream comprising the first and the second dissolving solvents; separating the first dissolving solvent from the second dissolving solvent contained ~ .
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in the stream produced by flashing the first heavy fraction;
passing the first dissolving solvent separated from the first heavy fraction into the first mixing zone for mixing with the coal; and passing the second dissolving solvent separated from the first heavy fraction into the second mixing zone for mixing with the prepared mixture to aid in providing the feed mixture.
The accompanying drawing comprises a single figure diagrammatically and schematically showing a coal deashing system arranged in accordance with the present invention.
Referring now to the drawing, general reference `
numeral 10 designates a coal deashing system arranged in accordance with the present invention; reference letters indicate the principal process steps of the invention.
In general, coal to be processed in accordance with the ~;
present invention is contacted and mixed with a first dlssolving 15 solvent in a first mixing zone A and processed to provide a ,~
prepared mixture which is passed into a second mixing zone B. ~ ;
In the second mixing zone B, the prepared mixture is mixed with ~ -a second dissolving solvent to provide a feed mixture which is passed to a first separation zone C
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wherein the feed mixtu~e is separated into a first heavv fraction and a first light fraction. The first light frac-tion then is passed into a second separation zone D wherein it is separated into a second light fraction and a second heavy fraction. In accordance with the present invention, the first dissolving solvent is recovered from the first and the second heavy fractions and recycled to the first mixing zone A to aid in the solubilization of the coal. The second dissolving solvent is recovered from the first and the second heavy fractions and recycled to the second mixing zone ~ to aid in producing the feed mixture. The reooverv and re-utilization of the first and the second dissolving solvents reduces the amounts of make-up of first and second dissolv-ing solvents which must be added to the coal deashing pro-cess, thereby reducing the cost o~ processing the coal andproviding a process which i9 more economical in operation.
The term "insoluble coal products" as used herein refers to tbe undissolved coal, ash, other solid inorganic particulate matter and other such matter which is insoluble in the dissolving solvent. The term "soluble coal products"
as used herein refers to the constituents in the coal which are soluble in the dissolving solvent.
Referring to the coal deashing process 10 of the present invention as depicte~ in the drawing, the first dis-solving solvent is passed from a first solvent surge vesselor the like (not shown) through a ~oncluit 26 into the first mixing zone A.
Pulverized coal maintained in a coal storage vessel or the like (not shown) is passed into the first mixing zone A through a conduit 28 at a rate controlled by a solids feeder . .
..
Z0~5 or the like (not shownj interposed in the conduit 28. The feed rates of ~he first dissolving solvent and the pulverized coal preferably are controlled to maintain the weight ratio of the first dissolving solvent to coal in the first mixing zone A within the range of from about one-to one to about twenty-to-one. More particularly, it has been ound desir-able to maintain the weight ratio of first dissolving sol-vent to coal in the first-mixing zone A in a range of from about two-to-one to about five-to-one; and best results have been obtained when the weight ratio was maintained at about :~
three-to-one. ..
In the first mixing zone A, the coal and the first . :~
dissolving solvent are agitated or mixed with a stirring : :
mechanism (not sh.own) at about ambient temperature and pres-sure to form a slurry. That slurry is withdrawn from the ~ .:
first mixing zone A through a~conduit 30 and pumped (pump not shown) to a heater 32 where the slurry is heated. In one :
preferred embodiment, gaseous hydrogen is passed from a source .~.
(not shown) through a conduit 34 çonnected to the conduit 30, . .
the gaseous hydrogen being mixed with the slurry flowing .
through the conduit 30 and the resulting mixture being heated - :
in the heater 32. A valve 36 is interposed in the conduit 34 : . .
for controlling the flow of the gaseous hydrogen to be mixed : : ~ .
with the slurry flowing through the conduit 30. ;.
The slurry, which may include the gaseous hydrogen, is discharged from the heater 32 at a temperature of about 800 degress F. and passed through a conduit 38 into a lique~
faction zone 40 to effect solubilizati.on of aobut ninety percent of the moisture and ash-free coal values. In one embodiment, the pressure leve:l in liqueEaction zone 40 is --4-- .
:
.- . . . . . : ,. . . . .: , , . .. . . .: ; . . , : .
. . .
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greater than about 12 psig and preferably in the range of about 12 psig to about 2000 psig.
In the liquefaction zone 40, the first dissolving solvent is contacted with the coal at the elevated liquefac-tion temperature and pressure for a period of time sufficient to solubilize most of the coal and produce a mixture of coal ; liquefactlon products (the soluble coal products), the dis-solving solvent and the insoluble coal products. The in-soluble coal products consist largely of the ash mineral ' 10 fraction of the coal.
' The mixture of soluble coal products, insoluble ,, coal products, first dissolving solvent and gases is with-drawn from the liquefaction zone'40 and passed through a conduit 42 into a gas separation zone 44, which includes a degassing vessel or the like, wherein the mixture is degassed by permitting the excess hydrogen, other gases and vapors to be discharged through a conduit 46. In some operational em-bodiments, the h~drogen-containing gases are discharged through the conduit 46 and passed to a hydrogen recycle sys-tem-(not shown) for re-use in the process. In one embodi- '' ment, the temperature level of the mixture in the gas sepa-ration zone 44 is about 800 degrees F. and the pressure level is in the range of from about 1200 psig to about 1500 psig.
The degassed mixture is discharged from the gas separation zone 44 and passed through the conduit 48 into the ' ' first flash zone 50, which includes a ~lash vessel or the ~' like (not shown~. In the first flash ~one 50, the mixture discharged from the gas separation zone 44, which includes soluble and insoluble coal products, i!3 flashed producing ~ ' one stream comprising the prepared mixture which is passed ~\
~zo~s from the first flash z~ne 50 through the conduit 16 and one other overhead stream comprising the first dissolving solvent which is passed through line 52 back to line 26 for re-use in the system~
In the operational embodiment referred to before, the pressure level in the first flash zone 50 is less than ~ :
about 20 psig. In one preferred operation of the process, the tempera~ure in the first flash zone 50 is maintained be- :
low about 650 degrees Fo The mixture consisting essentially of the soluble ;.coal products, the insoluble coal products and any remaining ~irst dissolving solvent (referred to herein as the "prepared mixture"1, is pumped (pump not shown) from the first flash zone 50 through the conduit 16 into the second mixing zone B. .:.
].5 The second dissolving solvent is introduced into the second mixing zone s via a conduit 54. The second dissolving sol- :
vent may be contained in a second solvent surge vessel or .~
the like (no~ shown) and, in this embodiment, the second : .
dissolving solvent is withdrawn from such vessel and pumped ~ :
through the conduit 54 into the second mixing zone B. In the second mixing zone B, the mixture discharged from the first flash zone 50 is contacted by and mixed with the second dissolving solvent and the resulting mixture is discharged from the second mixing zone B into and through the conduit ~0, ~ :
such resulting mixture comprising and being referxed to here-in as the "feed mixture." .~ :
The embodiment shown. in the drawing contemplates the utilization of two, different dissolving solvents, one of the dissolving solvents being introduced into the first mixing zone A and referred to herein as the "first dissolving -;
,,, :. .......... .
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solvent", and one other dissolving solvent being introduced into the second mixing zone B and referred to herein as the "second dissolving solvent." In one embodiment of the pre-sent invention shown in the drawiny, the first dissolving solvent preferably is an organic solvent suitable for lique-fying coal in the manner herein described. Various solvents suitable for use as the first dissolving solvent are described in detail in U.S. Patents 3,607,716, 3,607,717, 3,607,718 and 3,642,608. The second dissolving solvent is of the type ;
sometimes described as a "light organic solvent" in the ~ust-mentioned patents and include, for example, pyridine, ben-zene and toluene.
In the first separation zone C, the feed mixture is subjecte~ to a temperature of from about 460 degrees F. to àbout ~ degrees F. and a pressure in the range o~ from about ~ô50 psig to aobut lO00 psig whereupon it separates into a first light fraction and a first heavy fraction.
The first light fraction comprises the soluble coal products, some of the first dissolving solvent and some of the second dissolving solvent. The first light fraction is withdrawn from the first separation zone C and is passed through a heater 55 and a conduit 24 into the second separa-tion zone D. The first light fraction is heated in heater 55 to a temperature in the range of from about 630 degrees F.
to about 900 degrees F. and a pressure level in, the range of from about 650 psig to about lO00 psig and separates in the second separation zone D into (1) a s~3cond light fraction comprising most of the second dissolving solvent and t2~ a second heavy fraction~comprising the soluble coal products, the first dissolving solvent and some of the second dissolving ., .
32(~9~5 solvent. The second light fraction is wi-thdrawn from the second separation zone D and passed through a conduit 56 and the conduit 54, into the second mixing zone B to aid in providing the feed mixture.
The first heavy fraction is withdrawn from the first separation zone C and passed through line 60 into a second - `~
flash zone 58 where the pressure level of the first heavy fraction is reduced to a level in the range of from ahout 0 -psig to about 50 psig to flash the~first heavy fraction and produce one stream comprising the first and the second dis-solving solvents and one stream comprising the insoluble coal products. The insoluble coal products are withdrawn from the second flash zone 58 through a conduit 62. The -first and the second dissolving solvents are withdrawn from the second flash zone 58 and passed through a conduit 63 to separa'cor 72.
The second heavv fraction is withdrawn from the second separation zone D and passed into a third flash zone 64 via a conduit 66. In the third~flash zone 64, the pres-sure level of the second heavy fraction is reduced to a level in the range of from about 0 psig to about 50 psig to flash the second heavy fraction to produce one stream comprising the first and the second dissolviny solvents and one other -stream comprising the soluble coal products. The soluble coal products in the second heavy fraction are withdrawn from the third flash zone 64 through a conduit 68 for utilization or sale. The first and the second dissolving solvents in the second heavv fraction are withdrawn from t~e third flash zone 66 and passed thrvugh a conduit 70 to separator 72.
The streams (comprising the first and the second :.
.. . . . . . . . . .
.: . ' . , ,
Various coal deashing processes have been developed in the past wherein coal has been treated with one or more solvents and processed to separate the resulting insoluble coal products from the soluble coal products, some systems including provisions for recovering and recycling the solvents. For example, coal is contacted with a solvent and the resulting mixture then is separated into a heavy phase containing the insoluble coal products and a light phase containing the soluble coal products.
In such processes, the light phase is withdrawn and passed to downstream fractionating vessels wherein the soluble coal product is separated into multiple fractions.
The present invention provides a process comprising:
mixing in a first mixing zone a first dissolving solvent with coal solubilizing the coal, and flashing the resultant mixture to produce a prepared mixture comprising the first dissolving solvent, -~
20 the soluble coal products and the insoluble coal products; mixing ;
the prepared mixture with a second dissolving solvent to provide a feed mixture; introducing the feed mixture into a first separ-ation zone; separating the feed mixture in the first separation zone into a first heavy fraction comprising the insoluble coal products, some of the first dissolving solvent and some of the second dissolving solvent, and into a first light fraction; -flashing the first heavy fraction to produce one stream comprising the insoluble coal products and one other stream comprising the first and the second dissolving solvents; separating the first dissolving solvent from the second dissolving solvent contained ~ .
? , .
'' ' '' . ': ' ", ' , '' ', '' ,' " . ' ' ~
.. !, : ! ~
l$
in the stream produced by flashing the first heavy fraction;
passing the first dissolving solvent separated from the first heavy fraction into the first mixing zone for mixing with the coal; and passing the second dissolving solvent separated from the first heavy fraction into the second mixing zone for mixing with the prepared mixture to aid in providing the feed mixture.
The accompanying drawing comprises a single figure diagrammatically and schematically showing a coal deashing system arranged in accordance with the present invention.
Referring now to the drawing, general reference `
numeral 10 designates a coal deashing system arranged in accordance with the present invention; reference letters indicate the principal process steps of the invention.
In general, coal to be processed in accordance with the ~;
present invention is contacted and mixed with a first dlssolving 15 solvent in a first mixing zone A and processed to provide a ,~
prepared mixture which is passed into a second mixing zone B. ~ ;
In the second mixing zone B, the prepared mixture is mixed with ~ -a second dissolving solvent to provide a feed mixture which is passed to a first separation zone C
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' . . ' ' . ' . ' :lg~Z04S
wherein the feed mixtu~e is separated into a first heavv fraction and a first light fraction. The first light frac-tion then is passed into a second separation zone D wherein it is separated into a second light fraction and a second heavy fraction. In accordance with the present invention, the first dissolving solvent is recovered from the first and the second heavy fractions and recycled to the first mixing zone A to aid in the solubilization of the coal. The second dissolving solvent is recovered from the first and the second heavy fractions and recycled to the second mixing zone ~ to aid in producing the feed mixture. The reooverv and re-utilization of the first and the second dissolving solvents reduces the amounts of make-up of first and second dissolv-ing solvents which must be added to the coal deashing pro-cess, thereby reducing the cost o~ processing the coal andproviding a process which i9 more economical in operation.
The term "insoluble coal products" as used herein refers to tbe undissolved coal, ash, other solid inorganic particulate matter and other such matter which is insoluble in the dissolving solvent. The term "soluble coal products"
as used herein refers to the constituents in the coal which are soluble in the dissolving solvent.
Referring to the coal deashing process 10 of the present invention as depicte~ in the drawing, the first dis-solving solvent is passed from a first solvent surge vesselor the like (not shown) through a ~oncluit 26 into the first mixing zone A.
Pulverized coal maintained in a coal storage vessel or the like (not shown) is passed into the first mixing zone A through a conduit 28 at a rate controlled by a solids feeder . .
..
Z0~5 or the like (not shownj interposed in the conduit 28. The feed rates of ~he first dissolving solvent and the pulverized coal preferably are controlled to maintain the weight ratio of the first dissolving solvent to coal in the first mixing zone A within the range of from about one-to one to about twenty-to-one. More particularly, it has been ound desir-able to maintain the weight ratio of first dissolving sol-vent to coal in the first-mixing zone A in a range of from about two-to-one to about five-to-one; and best results have been obtained when the weight ratio was maintained at about :~
three-to-one. ..
In the first mixing zone A, the coal and the first . :~
dissolving solvent are agitated or mixed with a stirring : :
mechanism (not sh.own) at about ambient temperature and pres-sure to form a slurry. That slurry is withdrawn from the ~ .:
first mixing zone A through a~conduit 30 and pumped (pump not shown) to a heater 32 where the slurry is heated. In one :
preferred embodiment, gaseous hydrogen is passed from a source .~.
(not shown) through a conduit 34 çonnected to the conduit 30, . .
the gaseous hydrogen being mixed with the slurry flowing .
through the conduit 30 and the resulting mixture being heated - :
in the heater 32. A valve 36 is interposed in the conduit 34 : . .
for controlling the flow of the gaseous hydrogen to be mixed : : ~ .
with the slurry flowing through the conduit 30. ;.
The slurry, which may include the gaseous hydrogen, is discharged from the heater 32 at a temperature of about 800 degress F. and passed through a conduit 38 into a lique~
faction zone 40 to effect solubilizati.on of aobut ninety percent of the moisture and ash-free coal values. In one embodiment, the pressure leve:l in liqueEaction zone 40 is --4-- .
:
.- . . . . . : ,. . . . .: , , . .. . . .: ; . . , : .
. . .
1~9~l)4S
greater than about 12 psig and preferably in the range of about 12 psig to about 2000 psig.
In the liquefaction zone 40, the first dissolving solvent is contacted with the coal at the elevated liquefac-tion temperature and pressure for a period of time sufficient to solubilize most of the coal and produce a mixture of coal ; liquefactlon products (the soluble coal products), the dis-solving solvent and the insoluble coal products. The in-soluble coal products consist largely of the ash mineral ' 10 fraction of the coal.
' The mixture of soluble coal products, insoluble ,, coal products, first dissolving solvent and gases is with-drawn from the liquefaction zone'40 and passed through a conduit 42 into a gas separation zone 44, which includes a degassing vessel or the like, wherein the mixture is degassed by permitting the excess hydrogen, other gases and vapors to be discharged through a conduit 46. In some operational em-bodiments, the h~drogen-containing gases are discharged through the conduit 46 and passed to a hydrogen recycle sys-tem-(not shown) for re-use in the process. In one embodi- '' ment, the temperature level of the mixture in the gas sepa-ration zone 44 is about 800 degrees F. and the pressure level is in the range of from about 1200 psig to about 1500 psig.
The degassed mixture is discharged from the gas separation zone 44 and passed through the conduit 48 into the ' ' first flash zone 50, which includes a ~lash vessel or the ~' like (not shown~. In the first flash ~one 50, the mixture discharged from the gas separation zone 44, which includes soluble and insoluble coal products, i!3 flashed producing ~ ' one stream comprising the prepared mixture which is passed ~\
~zo~s from the first flash z~ne 50 through the conduit 16 and one other overhead stream comprising the first dissolving solvent which is passed through line 52 back to line 26 for re-use in the system~
In the operational embodiment referred to before, the pressure level in the first flash zone 50 is less than ~ :
about 20 psig. In one preferred operation of the process, the tempera~ure in the first flash zone 50 is maintained be- :
low about 650 degrees Fo The mixture consisting essentially of the soluble ;.coal products, the insoluble coal products and any remaining ~irst dissolving solvent (referred to herein as the "prepared mixture"1, is pumped (pump not shown) from the first flash zone 50 through the conduit 16 into the second mixing zone B. .:.
].5 The second dissolving solvent is introduced into the second mixing zone s via a conduit 54. The second dissolving sol- :
vent may be contained in a second solvent surge vessel or .~
the like (no~ shown) and, in this embodiment, the second : .
dissolving solvent is withdrawn from such vessel and pumped ~ :
through the conduit 54 into the second mixing zone B. In the second mixing zone B, the mixture discharged from the first flash zone 50 is contacted by and mixed with the second dissolving solvent and the resulting mixture is discharged from the second mixing zone B into and through the conduit ~0, ~ :
such resulting mixture comprising and being referxed to here-in as the "feed mixture." .~ :
The embodiment shown. in the drawing contemplates the utilization of two, different dissolving solvents, one of the dissolving solvents being introduced into the first mixing zone A and referred to herein as the "first dissolving -;
,,, :. .......... .
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. . . .... . ...
:1(39~(~4S
solvent", and one other dissolving solvent being introduced into the second mixing zone B and referred to herein as the "second dissolving solvent." In one embodiment of the pre-sent invention shown in the drawiny, the first dissolving solvent preferably is an organic solvent suitable for lique-fying coal in the manner herein described. Various solvents suitable for use as the first dissolving solvent are described in detail in U.S. Patents 3,607,716, 3,607,717, 3,607,718 and 3,642,608. The second dissolving solvent is of the type ;
sometimes described as a "light organic solvent" in the ~ust-mentioned patents and include, for example, pyridine, ben-zene and toluene.
In the first separation zone C, the feed mixture is subjecte~ to a temperature of from about 460 degrees F. to àbout ~ degrees F. and a pressure in the range o~ from about ~ô50 psig to aobut lO00 psig whereupon it separates into a first light fraction and a first heavy fraction.
The first light fraction comprises the soluble coal products, some of the first dissolving solvent and some of the second dissolving solvent. The first light fraction is withdrawn from the first separation zone C and is passed through a heater 55 and a conduit 24 into the second separa-tion zone D. The first light fraction is heated in heater 55 to a temperature in the range of from about 630 degrees F.
to about 900 degrees F. and a pressure level in, the range of from about 650 psig to about lO00 psig and separates in the second separation zone D into (1) a s~3cond light fraction comprising most of the second dissolving solvent and t2~ a second heavy fraction~comprising the soluble coal products, the first dissolving solvent and some of the second dissolving ., .
32(~9~5 solvent. The second light fraction is wi-thdrawn from the second separation zone D and passed through a conduit 56 and the conduit 54, into the second mixing zone B to aid in providing the feed mixture.
The first heavy fraction is withdrawn from the first separation zone C and passed through line 60 into a second - `~
flash zone 58 where the pressure level of the first heavy fraction is reduced to a level in the range of from ahout 0 -psig to about 50 psig to flash the~first heavy fraction and produce one stream comprising the first and the second dis-solving solvents and one stream comprising the insoluble coal products. The insoluble coal products are withdrawn from the second flash zone 58 through a conduit 62. The -first and the second dissolving solvents are withdrawn from the second flash zone 58 and passed through a conduit 63 to separa'cor 72.
The second heavv fraction is withdrawn from the second separation zone D and passed into a third flash zone 64 via a conduit 66. In the third~flash zone 64, the pres-sure level of the second heavy fraction is reduced to a level in the range of from about 0 psig to about 50 psig to flash the second heavy fraction to produce one stream comprising the first and the second dissolviny solvents and one other -stream comprising the soluble coal products. The soluble coal products in the second heavy fraction are withdrawn from the third flash zone 64 through a conduit 68 for utilization or sale. The first and the second dissolving solvents in the second heavv fraction are withdrawn from t~e third flash zone 66 and passed thrvugh a conduit 70 to separator 72.
The streams (comprising the first and the second :.
.. . . . . . . . . .
.: . ' . , ,
2(~S
dissolving solvents) enter a separator 72 where the first dissolving solvent is separated from the second dissolving solvent, for e~mple, by desti]lation. The first dissolving solvent is withdrawn from the separator 72 and passed through a conduit 74, which is connected to the conduit 62, into the first mixing zone A. The second dissolving solvent is with-drawn from the separator 72 and passed through a conduit 76, which is connected to the conduit 54, into the second mixing zone B. While a single separator, is illustrated in the drawing, it will be understood of course, that more than one may be employed in practicing the process of this invention.
Thus, the first dissolving solvent is separated from the second dissolving solvent in the separator 72 and the first dissolving solvent is recovered and recycled into the first mixing zone A via conduits 74 and 26 for mixing with the coal. The second dissolving solvent is recovered ,~ .
and recycled into the second mixing zone B for mixing with the prepared mixture to aid in providing the feed mixture.
The recovery and xecycling of the ~irst and the second dis-solving solvents reduces the amounts of make-up first and second dissolving solvents which must be added to the coal deashing process 10, thereby reducing the operating cost and providing a more economical coal deashing system. Further, the enhanced recovery of the first dissolving solvent re-sults in a reduction in the consumption of hyclrogen requiredin the coal dissolution step. Tha~ is, since the hydro-genated first dissolving solvent has been recovered for re-use, less fresh first dissol~ing solvent is needed, therefore less hydrogen is needed. Yet another advantage of this pro-cess i8 that it produces a deashed coal product which meets ~0920~S
~ , .
today's ecological requirements. The combination of bene~ficial aspects of the above described deashing process re-sults in a superior overall process.
It should be noted that it has been found that by lowering or reducing the temperature level in the first flash zone 50 it increases the amounts of the first dissolv- :-~
ing solvent in the prepared mixture, passed from the first ~ :
flash zone 50.
Changes may be made in the process apparatus or in -~ :
the steps of the process or in the sequence of the steps of ~ :
the process of the present invention without departing from the scope of the lnven~lon as defined in the eppended cleime.
' ' . ' .
:.
: ~ .
~ .
.
~ 10--' ' :
:.~ . :.. , . . , :
dissolving solvents) enter a separator 72 where the first dissolving solvent is separated from the second dissolving solvent, for e~mple, by desti]lation. The first dissolving solvent is withdrawn from the separator 72 and passed through a conduit 74, which is connected to the conduit 62, into the first mixing zone A. The second dissolving solvent is with-drawn from the separator 72 and passed through a conduit 76, which is connected to the conduit 54, into the second mixing zone B. While a single separator, is illustrated in the drawing, it will be understood of course, that more than one may be employed in practicing the process of this invention.
Thus, the first dissolving solvent is separated from the second dissolving solvent in the separator 72 and the first dissolving solvent is recovered and recycled into the first mixing zone A via conduits 74 and 26 for mixing with the coal. The second dissolving solvent is recovered ,~ .
and recycled into the second mixing zone B for mixing with the prepared mixture to aid in providing the feed mixture.
The recovery and xecycling of the ~irst and the second dis-solving solvents reduces the amounts of make-up first and second dissolving solvents which must be added to the coal deashing process 10, thereby reducing the operating cost and providing a more economical coal deashing system. Further, the enhanced recovery of the first dissolving solvent re-sults in a reduction in the consumption of hyclrogen requiredin the coal dissolution step. Tha~ is, since the hydro-genated first dissolving solvent has been recovered for re-use, less fresh first dissol~ing solvent is needed, therefore less hydrogen is needed. Yet another advantage of this pro-cess i8 that it produces a deashed coal product which meets ~0920~S
~ , .
today's ecological requirements. The combination of bene~ficial aspects of the above described deashing process re-sults in a superior overall process.
It should be noted that it has been found that by lowering or reducing the temperature level in the first flash zone 50 it increases the amounts of the first dissolv- :-~
ing solvent in the prepared mixture, passed from the first ~ :
flash zone 50.
Changes may be made in the process apparatus or in -~ :
the steps of the process or in the sequence of the steps of ~ :
the process of the present invention without departing from the scope of the lnven~lon as defined in the eppended cleime.
' ' . ' .
:.
: ~ .
~ .
.
~ 10--' ' :
:.~ . :.. , . . , :
Claims (8)
1. A process comprising: mixing in a first mixing zone a first dissolving solvent with coal at elevated temperature and pressure, and flashing the resultant mixture to produce a prepared mixture comprising the first dissolving solvent, the soluble coal products and the insoluble coal products;
mixing the prepared mixture with a second dissolving solvent in a second mixing zone to provide a feed mixture, said second solvent consisting essentially of at least one substance having a critical temperature below 800°F. selected from the group consisting of aromatic hydrocarbons having a single benzene nucleus and normal boiling points about 310°F.
cycloparaffin hydrocarbons having normal points below 310°F., open chain mono-olefin hydrocarbons having normal boiling points below about 310°F , open chain saturated hydrocarbons having normal boiling points below about 310°F., mono-di, and tri-open chain amines containing from about 2-8 carbon atoms, carbocyclic amines having a monocyclic structure containing from about 6-9 carbon atoms, heterocyclic amines containing from about 5-9 carbon atoms, and phenols containing from about 6-9 carbon atoms and their homologs; introducing the feed mixture into a first separation zone; maintaining the temperature level in the first separation zone in the range of from about 460°F. to about 620°F., and maintaining the pressure level in the first separation zone in the range of about 650 psig to about 1000 psig; separating the feed mixture in the first separation zone into a first heavy fraction comprising the insoluble coal products, some of the first dissolving solvent and some of the second dissolving solvent, and into a first light fraction: withdrawing the first light fraction from the first separation zone;
introducing the first light fraction into a second separation zone maintaining the temperature level in the second separation zone in the range of from about 630°F, to about 900°F. and the pressure level in the second separation zone in the range of from about 650 psig to about 1000 psig;
separating the first light fraction in the second separation zone into a second light fraction comprising the second dissolving solvent, and a second heavy fraction; withdrawing the second light fraction comprising the second dissolving solvent from the second separation zone; passing the second light fraction comprising the second dissolving solvent into the second mixing zone for mixing with the prepared mixture to aid in providing feed mixture, withdrawing the first heavy fraction from the first separation zone; flashing the first heavy fraction to produce one stream comprising the insoluble coal products and one other stream comprising the first and the second dissolving solvents; separating the first dissolving solvent from the second dissolving solvent contained in the stream which was produced by flashing the first heavy fraction;
passing the thus separated first dissolving solvent into the first mixing zone for mixing with the coal; and passing the thus separated second dissolving solvent into the second mixing zone for mixing with the prepared mixture to aid in providing the feed mixture.
mixing the prepared mixture with a second dissolving solvent in a second mixing zone to provide a feed mixture, said second solvent consisting essentially of at least one substance having a critical temperature below 800°F. selected from the group consisting of aromatic hydrocarbons having a single benzene nucleus and normal boiling points about 310°F.
cycloparaffin hydrocarbons having normal points below 310°F., open chain mono-olefin hydrocarbons having normal boiling points below about 310°F , open chain saturated hydrocarbons having normal boiling points below about 310°F., mono-di, and tri-open chain amines containing from about 2-8 carbon atoms, carbocyclic amines having a monocyclic structure containing from about 6-9 carbon atoms, heterocyclic amines containing from about 5-9 carbon atoms, and phenols containing from about 6-9 carbon atoms and their homologs; introducing the feed mixture into a first separation zone; maintaining the temperature level in the first separation zone in the range of from about 460°F. to about 620°F., and maintaining the pressure level in the first separation zone in the range of about 650 psig to about 1000 psig; separating the feed mixture in the first separation zone into a first heavy fraction comprising the insoluble coal products, some of the first dissolving solvent and some of the second dissolving solvent, and into a first light fraction: withdrawing the first light fraction from the first separation zone;
introducing the first light fraction into a second separation zone maintaining the temperature level in the second separation zone in the range of from about 630°F, to about 900°F. and the pressure level in the second separation zone in the range of from about 650 psig to about 1000 psig;
separating the first light fraction in the second separation zone into a second light fraction comprising the second dissolving solvent, and a second heavy fraction; withdrawing the second light fraction comprising the second dissolving solvent from the second separation zone; passing the second light fraction comprising the second dissolving solvent into the second mixing zone for mixing with the prepared mixture to aid in providing feed mixture, withdrawing the first heavy fraction from the first separation zone; flashing the first heavy fraction to produce one stream comprising the insoluble coal products and one other stream comprising the first and the second dissolving solvents; separating the first dissolving solvent from the second dissolving solvent contained in the stream which was produced by flashing the first heavy fraction;
passing the thus separated first dissolving solvent into the first mixing zone for mixing with the coal; and passing the thus separated second dissolving solvent into the second mixing zone for mixing with the prepared mixture to aid in providing the feed mixture.
2. The process of claim 1 defined further to include the step of: heating the first light fraction withdrawn from the first separation zone before introducing the first light fraction into the second separation zone.
3. The process of claim 1 wherein the step of solubi-lizing and flashing the mixture to provide the prepared mixture is defined further to include the steps of: heating the mixture of coal and the first dissolving solvent with-drawn from the first mixing zone; adding gaseous hydrogen to the mixture of coal and first dissolving solvent;
liquefying the mixture of coal, gaseous hydrogen and the first dissolving solvent in a liquefaction zone by heating the mixture to a temperature of about 800° F. and maintaining the pressure level in the range of from about 1200 psig to about 2000 psig to solubilize the coal to produce a mixture comprising the soluble coal products, the insoluble coal products, the first dissolving solvent and the gaseous hydrogen; withdrawing the mixture from the liquefaction zone; introducing the mixture withdrawn from the liquefaction zone into a gas separation zone; separating the gaseous hydrogen from the mixture withdrawn from the liquefaction zone in the gas separation zone; and flashing the degassed mixture in a first flash zone to produce at least one stream comprising the prepared mixture.
liquefying the mixture of coal, gaseous hydrogen and the first dissolving solvent in a liquefaction zone by heating the mixture to a temperature of about 800° F. and maintaining the pressure level in the range of from about 1200 psig to about 2000 psig to solubilize the coal to produce a mixture comprising the soluble coal products, the insoluble coal products, the first dissolving solvent and the gaseous hydrogen; withdrawing the mixture from the liquefaction zone; introducing the mixture withdrawn from the liquefaction zone into a gas separation zone; separating the gaseous hydrogen from the mixture withdrawn from the liquefaction zone in the gas separation zone; and flashing the degassed mixture in a first flash zone to produce at least one stream comprising the prepared mixture.
4. A process comprising: mixing in a first mixing zone a first dissolving solvent with coal, solubilizing the coal at elevated temperature and pressure, and flashing the resultant mixture to produce a prepared mixture comprising the first dissolving solvent, the soluble coal products and the insoluble coal products; mixing the prepared mixture with a second dissolving solvent in a second zone to provide a feed mixture, said second dissolving solvent consisting essentially of at least one substance having a critical temperature below 800° F. selected from the group consisting of aromatic hydrocarbons having a single benzene nucleus and normal boiling points below about 310°F., cycloparaffin hydrocarbons having normal boiling points below about 310°F., open chain mono-olefin hydrocarbons having normal boiling points below about 310°F., open chain saturated hydrocarbons having normal boiling points below about 310°F., mono-, di, and tri-open chain amines containing from about 2-8 carbon atoms, carbocyclic amines having a monocyclic structure containing from about 6-9 carbon atoms, heterocyclic amines containing from about 5-9 carbon atoms, and phenols containing from about 6-9 carbon atoms and their homologs;
introducing the feed mixture into a first separation zone;
maintaining the temperature level in the first separation zone in the range of from about 460°F. to about 620°F., and maintaining the pressure level in the first separation zone in the range of from 650 psig to about 1000 psig; separating the feed mixture in the first separation zone into a first heavy fraction comprising the insoluble coal products, some of the first dissolving solvent and some of the second dissolving solvent, and into a first light fraction; withdrawing the first heavy fraction from the first separation zone; flashing the first heavy fraction to produce one stream comprising the insoluble coal products and one other stream comprising the first and the second dissolving solvents; separating the first dissolving solvent from the second dissolving solvent contained in the stream which was produced by flashing the first heavy fraction;
passing the thus separated first dissolving solvent into the first mixing zone for mixing with the coal; passing the thus separated second dissolving solvent into the second mixing zone for mixing with the prepared mixture to aid in providing the feed mixture; withdrawing the first light fraction from the first separation zone; introducing the first light fraction into a second separation zone;
maintaining the temperature level in the second separation zone in the range of from about 630°F. to about 900°F.
and the pressure level in the second separation zone in the range. of from about 650 psig to about 1000 psig; separating the first light fraction in the second separation zone into a second light fraction and a second heavy fraction comprising the soluble coal products, some of the second dissolving solvents and some of the first dissolving solvent; withdraw-ing the second heavy fraction from the second separation zone;
flashing the second heavy fraction to produce one stream comprising the first and the second dissolving solvents and one other stream comprising the soluble coal products;
separating the first dissolving solvent from the second dissolving solvent contained in the stream which was produced by flashing from the second heavy fraction; passing the second dissolving solvent thus separated into the second mixing zone for mixing with the prepared mixture to aid in producing the feed mixture; and passing the first dissolving solvent thus separated into the first mixing zone for mixing with the coal.
introducing the feed mixture into a first separation zone;
maintaining the temperature level in the first separation zone in the range of from about 460°F. to about 620°F., and maintaining the pressure level in the first separation zone in the range of from 650 psig to about 1000 psig; separating the feed mixture in the first separation zone into a first heavy fraction comprising the insoluble coal products, some of the first dissolving solvent and some of the second dissolving solvent, and into a first light fraction; withdrawing the first heavy fraction from the first separation zone; flashing the first heavy fraction to produce one stream comprising the insoluble coal products and one other stream comprising the first and the second dissolving solvents; separating the first dissolving solvent from the second dissolving solvent contained in the stream which was produced by flashing the first heavy fraction;
passing the thus separated first dissolving solvent into the first mixing zone for mixing with the coal; passing the thus separated second dissolving solvent into the second mixing zone for mixing with the prepared mixture to aid in providing the feed mixture; withdrawing the first light fraction from the first separation zone; introducing the first light fraction into a second separation zone;
maintaining the temperature level in the second separation zone in the range of from about 630°F. to about 900°F.
and the pressure level in the second separation zone in the range. of from about 650 psig to about 1000 psig; separating the first light fraction in the second separation zone into a second light fraction and a second heavy fraction comprising the soluble coal products, some of the second dissolving solvents and some of the first dissolving solvent; withdraw-ing the second heavy fraction from the second separation zone;
flashing the second heavy fraction to produce one stream comprising the first and the second dissolving solvents and one other stream comprising the soluble coal products;
separating the first dissolving solvent from the second dissolving solvent contained in the stream which was produced by flashing from the second heavy fraction; passing the second dissolving solvent thus separated into the second mixing zone for mixing with the prepared mixture to aid in producing the feed mixture; and passing the first dissolving solvent thus separated into the first mixing zone for mixing with the coal.
5. The process of claim 4 wherein the steps of separating the first dissolving solvent from the second dissolving solvent contained in the streams produced by flashing the first and the second heavy fractions are defined further to include; introducing the stream comprising the first and the second dissolving solvents which was produced by flashing the first heavy fraction into a separator; introducing the stream comprising the first and the second dissolving solvents which was produced by flashing the second heavy fraction into a separator; separating in the separator the first dissolving solvent from the second dissolving solvent;
withdrawing the first dissolving solvent from the separa-tor; and withdrawing the second dissolving solvent from the separator; and wherein the step of passing the first dis-solving solvent separated from the first heavy fraction into the first mixing zone is defined further as passing the first dis-solving solvent withdrawn from the separator into the first mixing zone for mixing with the coal; and wherein the first step of passing the second dissolving solvent separated from the first heavy fraction into the second mixing zone is defined further as passing the second dis-solving solvent withdrawn from the separator into the second mixing zone for mixing with the prepared mixture to aid in producing the feed mixture; and wherein the step of passing the second dissolving solvent separated from the second heavy fraction into the second mixing zone is de-fined further as passing the second dissolving solvent withdrawn from the separator into the second mixing zone for mixing with the prepared mixture to aid in producing the feed mixture; and wherein the step of passing the first dissolving solvent separated from the second heavy fraction into the first mixing zone is defined further as passing the first dissolving solvent into the first mixing zone for mixing with coal to aid in producing the feed mixture.
withdrawing the first dissolving solvent from the separa-tor; and withdrawing the second dissolving solvent from the separator; and wherein the step of passing the first dis-solving solvent separated from the first heavy fraction into the first mixing zone is defined further as passing the first dis-solving solvent withdrawn from the separator into the first mixing zone for mixing with the coal; and wherein the first step of passing the second dissolving solvent separated from the first heavy fraction into the second mixing zone is defined further as passing the second dis-solving solvent withdrawn from the separator into the second mixing zone for mixing with the prepared mixture to aid in producing the feed mixture; and wherein the step of passing the second dissolving solvent separated from the second heavy fraction into the second mixing zone is de-fined further as passing the second dissolving solvent withdrawn from the separator into the second mixing zone for mixing with the prepared mixture to aid in producing the feed mixture; and wherein the step of passing the first dissolving solvent separated from the second heavy fraction into the first mixing zone is defined further as passing the first dissolving solvent into the first mixing zone for mixing with coal to aid in producing the feed mixture.
6. The process of claim 4 defined further to include the step of: heating the first light fraction withdrawn from the first separation zone before introducing the first light fraction into the second separation zone.
7. The process of claim 4 wherein the step of solubi-lizing the flashing the mixture to provide the prepared mixture is defined further to include the steps of:
heating the mixture of coal and the first dissolving solvent withdrawn from the first mixing zone; adding gaseous hydrogen to the mixture of coal and first dissolving solvent;
liquefying the mixture of coal, gaseous hydrogen and the first dissolving solvent in a liquefaction zone by heating the mixture to a temperature of about 800° F. and maintaining the pressure level in the range of from about 1200 to about 2000 psig to solubilize the coal to produce a mixture comprising the soluble coal products, the insoluble coal products, the first dissolving solvent and the gaseous hydrogen; withdrawing the mixture from the liquefaction zone; introducing the mixture withdrawn from the liquefaction zone into a gas separation zone; separating the gaseous hydrogen from the mixture withdrawn from the liquefaction zone in the gas separation zone; and flashing the degassed mixture in a first flash zone to produce at least one stream comprising the prepared mixture.
heating the mixture of coal and the first dissolving solvent withdrawn from the first mixing zone; adding gaseous hydrogen to the mixture of coal and first dissolving solvent;
liquefying the mixture of coal, gaseous hydrogen and the first dissolving solvent in a liquefaction zone by heating the mixture to a temperature of about 800° F. and maintaining the pressure level in the range of from about 1200 to about 2000 psig to solubilize the coal to produce a mixture comprising the soluble coal products, the insoluble coal products, the first dissolving solvent and the gaseous hydrogen; withdrawing the mixture from the liquefaction zone; introducing the mixture withdrawn from the liquefaction zone into a gas separation zone; separating the gaseous hydrogen from the mixture withdrawn from the liquefaction zone in the gas separation zone; and flashing the degassed mixture in a first flash zone to produce at least one stream comprising the prepared mixture.
8. A process comprising: Mixing in a first mixing zone a first dissolving solvent with coal; solubilizing the coal at elevated temperatures and pressures and flashing the resultant mixture to produce a prepared mixture comprising the first dissolving solvent, the soluble coal products, and the insoluble coal products;
mixing the prepared mixture with a second dissolving solvent in a second mixing zone to provide a feed mixture, said second dissolving solvent consisteing essentially of at least one substance having a critical temperature below 800° F.
selected from the group consisting of aromatic hydrocarbons having a single benzene nucleus and normal boiling points below about 310° F., cycloparaffin hydrocarbons having normal boiling points below about 310° F., open chain mono-olefin hydrocarbons having normal boiling points below about 310°
F., open chain saturated hydrocarbons having normal boiling points below about 310° F., mono-di, and tri-open chain amines containing from about 2-8 carbon atoms, carbocyclic amines having a monocyclic structure containing from about 6-9 carbon atoms heterocyclic amines containing from about 5-9 carbon atoms, and phenols containing from about 6-9 carbon atoms and their homologs; introducing the feed mixture into a first separation zone; maintaining the temperature level in the first separation zone in a range of from about 460° F., to about 620° F., and maintaining the pressure level in the first separation zone in the range of from about 650 psig to about 1000 psig;
separating the feed mixture in the first separation zone into a first heavy fraction and into a first light fraction comprising the soluble coal products, some of the first dissolving solvent, and some of the second dissolving solvent; withdrawing the first light fraction from the first separation zone; introducing the first light fraction into a second separation zone; maintaining the temperature level in the second separation zone in the range of from about 630° F. to about 900° F. and the pressure level in the second separation zone in the range of from about 650 psig to about 1000 psig; separating the first light fraction in the second separation zone into a second light fraction and into a second heavy fraction comprising the soluble coal products, some of the first dissolving solvent and some of the second dissolving solvent; withdrawing the second heavy fraction from the second separation zone;
flashing the second heavy fraction to produce one stream comprising the first and the second dissolving solvents and one other stream comprising the soluble coal products;
separating the first dissolving solvent from the second dissolving solvent contained in the stream which was produced by flashing the second heavy fraction; passing the second dissolving solvent thus separated into the second mixing zone for mixing with the prepared mixture to aid in producing the feed mixture; and passing the first dissolving solvent thus separated into the first mixing zone for mixing with coal.
mixing the prepared mixture with a second dissolving solvent in a second mixing zone to provide a feed mixture, said second dissolving solvent consisteing essentially of at least one substance having a critical temperature below 800° F.
selected from the group consisting of aromatic hydrocarbons having a single benzene nucleus and normal boiling points below about 310° F., cycloparaffin hydrocarbons having normal boiling points below about 310° F., open chain mono-olefin hydrocarbons having normal boiling points below about 310°
F., open chain saturated hydrocarbons having normal boiling points below about 310° F., mono-di, and tri-open chain amines containing from about 2-8 carbon atoms, carbocyclic amines having a monocyclic structure containing from about 6-9 carbon atoms heterocyclic amines containing from about 5-9 carbon atoms, and phenols containing from about 6-9 carbon atoms and their homologs; introducing the feed mixture into a first separation zone; maintaining the temperature level in the first separation zone in a range of from about 460° F., to about 620° F., and maintaining the pressure level in the first separation zone in the range of from about 650 psig to about 1000 psig;
separating the feed mixture in the first separation zone into a first heavy fraction and into a first light fraction comprising the soluble coal products, some of the first dissolving solvent, and some of the second dissolving solvent; withdrawing the first light fraction from the first separation zone; introducing the first light fraction into a second separation zone; maintaining the temperature level in the second separation zone in the range of from about 630° F. to about 900° F. and the pressure level in the second separation zone in the range of from about 650 psig to about 1000 psig; separating the first light fraction in the second separation zone into a second light fraction and into a second heavy fraction comprising the soluble coal products, some of the first dissolving solvent and some of the second dissolving solvent; withdrawing the second heavy fraction from the second separation zone;
flashing the second heavy fraction to produce one stream comprising the first and the second dissolving solvents and one other stream comprising the soluble coal products;
separating the first dissolving solvent from the second dissolving solvent contained in the stream which was produced by flashing the second heavy fraction; passing the second dissolving solvent thus separated into the second mixing zone for mixing with the prepared mixture to aid in producing the feed mixture; and passing the first dissolving solvent thus separated into the first mixing zone for mixing with coal.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US05/691,575 US4119524A (en) | 1976-06-01 | 1976-06-01 | Coal deashing process having improved solvent recovery techniques |
| US691,575 | 1985-01-15 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1092045A true CA1092045A (en) | 1980-12-23 |
Family
ID=24777091
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA279,526A Expired CA1092045A (en) | 1976-06-01 | 1977-05-31 | Coal deashing process having improved solvent recovery techniques |
Country Status (7)
| Country | Link |
|---|---|
| US (1) | US4119524A (en) |
| JP (1) | JPS5316704A (en) |
| AU (1) | AU504761B2 (en) |
| CA (1) | CA1092045A (en) |
| DE (1) | DE2725022A1 (en) |
| GB (1) | GB1543457A (en) |
| ZA (1) | ZA773145B (en) |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4244812A (en) * | 1978-12-28 | 1981-01-13 | Kerr-Mcgee Corporation | System for producing a powdery composition comprising coal products in a coal deashing process |
| US4272501A (en) * | 1980-03-03 | 1981-06-09 | International Coal Refining Company | Carbon fibers from SRC pitch |
| US4313819A (en) * | 1980-05-22 | 1982-02-02 | Kerr-Mcgee Corporation | Process for recovering deashing solvent from insoluble coal products |
| US4374015A (en) * | 1981-03-09 | 1983-02-15 | Kerr-Mcgee Corporation | Process for the liquefaction of coal |
| US4405437A (en) * | 1982-01-11 | 1983-09-20 | Electric Power Research Institute | Process for coal liquefaction employing a superior coal liquefaction process solvent |
| US4476009A (en) * | 1983-03-24 | 1984-10-09 | Texaco Inc. | Process for improving the hydrogen donor properties of a coal liquefaction solvent |
| US4534847A (en) * | 1984-01-16 | 1985-08-13 | International Coal Refining Company | Process for producing low-sulfur boiler fuel by hydrotreatment of solvent deashed SRC |
| JPH0160904U (en) * | 1987-10-14 | 1989-04-18 | ||
| JP2014189740A (en) * | 2013-03-28 | 2014-10-06 | Kobe Steel Ltd | Apparatus and method for production of ashless coal |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2476999A (en) * | 1947-07-24 | 1949-07-26 | Orchin Milton | Solvation and depolymerization of coal |
| US3607716A (en) * | 1970-01-09 | 1971-09-21 | Kerr Mc Gee Chem Corp | Fractionation of coal liquefaction products in a mixture of heavy and light organic solvents |
| US3607717A (en) * | 1970-01-09 | 1971-09-21 | Kerr Mc Gee Chem Corp | Fractionating coal liquefaction products with light organic solvents |
| US3974073A (en) * | 1974-09-06 | 1976-08-10 | The Lummus Company | Coal liquefaction |
| US3852183A (en) * | 1972-12-29 | 1974-12-03 | Lummus Co | Coal liquefaction |
| US3791956A (en) * | 1973-02-16 | 1974-02-12 | Consolidation Coal Co | Conversion of coal to clean fuel |
| US3954595A (en) * | 1974-03-18 | 1976-05-04 | The Lummus Company | Coal liquefaction |
| US3997425A (en) * | 1974-12-26 | 1976-12-14 | Universal Oil Products Company | Process for the liquefaction of coal |
-
1976
- 1976-06-01 US US05/691,575 patent/US4119524A/en not_active Expired - Lifetime
-
1977
- 1977-05-24 GB GB21865/77A patent/GB1543457A/en not_active Expired
- 1977-05-25 ZA ZA00773145A patent/ZA773145B/en unknown
- 1977-05-25 AU AU25510/77A patent/AU504761B2/en not_active Expired
- 1977-05-31 CA CA279,526A patent/CA1092045A/en not_active Expired
- 1977-05-31 DE DE19772725022 patent/DE2725022A1/en not_active Ceased
- 1977-06-01 JP JP6456277A patent/JPS5316704A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| AU2551077A (en) | 1978-11-30 |
| GB1543457A (en) | 1979-04-04 |
| JPS5614708B2 (en) | 1981-04-06 |
| ZA773145B (en) | 1978-04-26 |
| AU504761B2 (en) | 1979-10-25 |
| DE2725022A1 (en) | 1977-12-22 |
| JPS5316704A (en) | 1978-02-16 |
| US4119524A (en) | 1978-10-10 |
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