CA1214419A - Coal slurry and deoxygenating process for coal liquefaction - Google Patents
Coal slurry and deoxygenating process for coal liquefactionInfo
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- CA1214419A CA1214419A CA000439947A CA439947A CA1214419A CA 1214419 A CA1214419 A CA 1214419A CA 000439947 A CA000439947 A CA 000439947A CA 439947 A CA439947 A CA 439947A CA 1214419 A CA1214419 A CA 1214419A
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- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
- C10G1/00—Production of liquid hydrocarbon mixtures from oil-shale, oil-sand, or non-melting solid carbonaceous or similar materials, e.g. wood, coal
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- General Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)
- Liquid Carbonaceous Fuels (AREA)
Abstract
ABSTRACT
A process for drying and deoxygenating coal-oil slurry prior to liquefaction of the coal. In the process, the coal having particle size of 30-375 mesh (U. S. Sieve Series) is mixed with a slurrying oil derived from a coal liquefaction process at 250-650°F mixing temperature and 0-150 psig pressure. During the mixing step, moisture in the coal is evolved to less than about 3.0 W % moisture remaining, along with substantial removal of the oxygen contained in the coal. The process produces a dried more reactive coal slurry for feed to a coal liquefaction process for achieving increased conversion of the coal and producing more desirable low boiling hydrocarbon liquid products.
A process for drying and deoxygenating coal-oil slurry prior to liquefaction of the coal. In the process, the coal having particle size of 30-375 mesh (U. S. Sieve Series) is mixed with a slurrying oil derived from a coal liquefaction process at 250-650°F mixing temperature and 0-150 psig pressure. During the mixing step, moisture in the coal is evolved to less than about 3.0 W % moisture remaining, along with substantial removal of the oxygen contained in the coal. The process produces a dried more reactive coal slurry for feed to a coal liquefaction process for achieving increased conversion of the coal and producing more desirable low boiling hydrocarbon liquid products.
Description
COAL SLURRY DRYING AMD DEOXYGENATIMG PROCESS, FOR COAL LIQUEFACTION
BACKGROU~ID OF INVENTIOM
This invention pertains to drying and deoxygenating coal by heating the coal in a hot slurrying oil It pertains particularly to a process for drying and deoxygenating coal in a coal slurry at 250-650~F temperature prior to feeding the slurry to a coal liquefaction process In coal liquefaction processes, the raw coal is ini-tially crushed and dried to remove surface and contained moisture down to Less than about 3 W % moisture remaining~
usually by using sensible heat such as by passing the coal through a drying tunnel. Also, the raw coal usually con-tains some undesired oxygen. A major disadvantage of high oxygen content in coal feed for liquefaction processes is that the oxygen cosnbines with expensive hydrogen to produce water of no commercial value. Also oxygenated compounds contained in the hydrocarbon liquid products from coal liquefaction processes are not pre~erred in liquid fuels for transportation uses. The oxygen compounds also contribute to regressive reaction~ and producP unreactive insoluble organic meterials.
Schafer has reported in Fuels 59, May, 1~80, pp. 295-304, that coal dried by pyrolysis procedures decarboxylate, i.e., rémovP COOH (carboxyl group), under increasing temper-ature condition~ to yield carbon dioxide, carbon monoxide and water. For each molecule of carbon dioxide produced, one molecule of tightly bound water was also lost from the dried coal. The effects of bound water and c~rbon dio~ide are more profound in lower rank coals, since th~y contain more carboxyl groups and hence more water than higher rank coals. Physical and chemical properties of low rank coals, as well as coal liquefaction process responses, are believed to ~e adversely i~fluenced by the presence of tightly-held water an~ carboxyl groups in the coal. These oxygen-containing species are known to decrease hydrogen partial pressure and coal conversion in the coal liquefaction reac~or, increa~e hydrogen consumption, affect diffusion properties, incr~ase separation and disposal requirements and hence adversely affect th~ economics of coal liquefac-tion processes.
In direct coal liquefaction processes a temperature controlled mixing vessel i~ utilized for blending the par-ticulate coal with a hot slurrying oil- The slurrying oil is usually processed derived, then treat~d for removal of gases, moisture and light naphtha, and cooled before being recycled to the slurrying step~ V. S. Patent No. 4,209,911 to Weber disclose~ a process for drying coal in a ~lurry mixing tank prior to coal li~uefaction. But Weber does not di~close any deoxygenation of the coal or increase~ in slurry reactivities at more severe drying conditions~as are provided by the present invention.
SUMMARY OF IMVENTION
The invention provides a process for drying and deoxy-.
genating coal in a coal~oil ~lurry mixing vessel, maintained at elevated temperatures. The invention compri~es a process for drying .and deoxygenating particulate coal to remove moi~ture and oxygen contained therein, comprisinq the steps of mixing a particulate coal feed with a hydrocarbon slur~y-ing oil in a mixing zone to provide a coal-oil slurry mix-ture having an oil/coal ratio of from aoout 1.2 to about
BACKGROU~ID OF INVENTIOM
This invention pertains to drying and deoxygenating coal by heating the coal in a hot slurrying oil It pertains particularly to a process for drying and deoxygenating coal in a coal slurry at 250-650~F temperature prior to feeding the slurry to a coal liquefaction process In coal liquefaction processes, the raw coal is ini-tially crushed and dried to remove surface and contained moisture down to Less than about 3 W % moisture remaining~
usually by using sensible heat such as by passing the coal through a drying tunnel. Also, the raw coal usually con-tains some undesired oxygen. A major disadvantage of high oxygen content in coal feed for liquefaction processes is that the oxygen cosnbines with expensive hydrogen to produce water of no commercial value. Also oxygenated compounds contained in the hydrocarbon liquid products from coal liquefaction processes are not pre~erred in liquid fuels for transportation uses. The oxygen compounds also contribute to regressive reaction~ and producP unreactive insoluble organic meterials.
Schafer has reported in Fuels 59, May, 1~80, pp. 295-304, that coal dried by pyrolysis procedures decarboxylate, i.e., rémovP COOH (carboxyl group), under increasing temper-ature condition~ to yield carbon dioxide, carbon monoxide and water. For each molecule of carbon dioxide produced, one molecule of tightly bound water was also lost from the dried coal. The effects of bound water and c~rbon dio~ide are more profound in lower rank coals, since th~y contain more carboxyl groups and hence more water than higher rank coals. Physical and chemical properties of low rank coals, as well as coal liquefaction process responses, are believed to ~e adversely i~fluenced by the presence of tightly-held water an~ carboxyl groups in the coal. These oxygen-containing species are known to decrease hydrogen partial pressure and coal conversion in the coal liquefaction reac~or, increa~e hydrogen consumption, affect diffusion properties, incr~ase separation and disposal requirements and hence adversely affect th~ economics of coal liquefac-tion processes.
In direct coal liquefaction processes a temperature controlled mixing vessel i~ utilized for blending the par-ticulate coal with a hot slurrying oil- The slurrying oil is usually processed derived, then treat~d for removal of gases, moisture and light naphtha, and cooled before being recycled to the slurrying step~ V. S. Patent No. 4,209,911 to Weber disclose~ a process for drying coal in a ~lurry mixing tank prior to coal li~uefaction. But Weber does not di~close any deoxygenation of the coal or increase~ in slurry reactivities at more severe drying conditions~as are provided by the present invention.
SUMMARY OF IMVENTION
The invention provides a process for drying and deoxy-.
genating coal in a coal~oil ~lurry mixing vessel, maintained at elevated temperatures. The invention compri~es a process for drying .and deoxygenating particulate coal to remove moi~ture and oxygen contained therein, comprisinq the steps of mixing a particulate coal feed with a hydrocarbon slur~y-ing oil in a mixing zone to provide a coal-oil slurry mix-ture having an oil/coal ratio of from aoout 1.2 to about
2.5; heating said coal-oil slurry mixture to 230-650F tem-perature to evolve moisture and oxygen vapors ~rom the coal;
and withdrawing a dried coal-oil slurry mixture containing reduced moisture and oxygen contents. By using the inven-tion, the water and oxygen content of the coal ~lurry are lowered and the relative reactivity of coal slurries con-taining bituminous and low rank sub-bituminous coals and similar organic deposits are increased by raising the coal-oil slurry temperature in tha slurry mixing vessel to at least about 240F and usually not exceeding about 650F.
Moisture remaining in the heated coal oil slurry is reduced to less than about 3 W ~, and the oxygen content is reduced to less than about 7 W ~. Also, a more reactive slurry is provided which produce~ a higher hydrogen partial pressure in the reactor and increases coal total conversion to pro-duct oils. At a given total reaction pressure, the inven-tion will improve product quality, and decrease energy requirements of cooling the recycle streams.
This coal drying and deoxygenation step is usually ac-complished in a single mixing vessel, however if desired, two or three staged mixing vessels can be use~ at increasing temperature and pressure conditions. Although this coal drying and deoxygenation step can be used to provide a dried coal-oil slurry stream as a fuel, it is preferably used as a pretreatment step for a coal feedstream to a coal liquefaction process~ and more pre~erably provides a feedstream to ~ catalytic coal liquefaction process.
Accordingly, when this coal drying and deox~genation step is used in a coal liquefaction process, it is intended to decrease H2 consumption, increase coal conversion, im-prove product quality, decrease the energy requirements of cooling the recycle streams, and thus improve the economics of direct coal liquefaction or for lignin upgrading. ~ne same beneits are also expected when processing coals con-taining higher concentrations of mineral matter and which contain clay water by decreasing or eliminating condensation reaction products caused by evolution of steam vapor from the clay.
_ _ _ _ FIG. 1 shows a schematic flow diagram of a process for drying and deoxygen~ting coal-oil slurry in accordance with the invention.
FIG. 2 shows a schematic flow diagram of the coal slurry dr~ing step operated upstream of a catalytic coal liquefac-tion process.
FIG. 3 ~hows two graphs of coal deoxygenation and con-version results from increasing slurry tank temperatures.
FIG. 4 shows a graph of decreasing yield of residual oil (975F+ fraction) for increasing slurry mixing tank temperature.
DESCRIPTION OF INVENTION
_ _ This invention will be further described as a coal pre~
treatment step for a coal liquefaction process. As shown in FIG. 1, raw coal at 10 is crushed or ground and screened at 12 to provide a particle size range of 30 375 mesh ~U. S, Sieve Serie-~). If desired, the coal can also be cleaned or beneficiated to remove mineral matter. The particulate coal a~ 13 is then fed into slurry mixing tank 14, where it is mixed with a hydrocarbon slurrying oil 16 having a norm~l boiling ran~e of about 500-750Fo The tank pressure is main-tained at 0-150 psig and preferably at 0-50 psig pre~ure by a portion of process-derived recycle gas stream. Th~ par-ticulate coal at 13 can be fed to the ~ixing vessel 14 through a conventional pres~urized lock hopper or via a screw or star type feeder (not show~)..
Effective mixing of the particulate coal and slurrying oil is achieved by providing a liquid velocity within the tank 14 of at least about 2 ft/sec. The coal and oil in the atmospheric pressure or pressurized mixing tank can be mixed by u~ing an angled agitator or mixer, baffle plate(s) and recycle circulation lines or ~imilar mechanical devices o provide a well mixed coal-oil slurry. Such mixing ~an be effectively provided either by a rotary mixer 15 mounted in the tank, or by the recycle to the tank of a portion 17a of slurry stream 17 by pump 18, or by both arrangements.
The slurry temperature in mixing tank 14 is maintained at 250-650F by recycling the hot slurryin~ oil 16 usually at about 550-700F temperature. Th~ slurry tank temperature is preferably 35Q-50QF. The tank 14 is usually provided with ~ternal thermal insulation 14a to conserve heat and heIp maintain the desired ~lurry temperature therein. The re~idence time for the coal in tank 14 will depend on the moi~ture content of th~ coal feed and the extent of drying de~ir~d, and u~ually ranges from about 0.2 hours at high drying.temper~ture of 650F and up to about 3 hours for high -moisture coals and lower drying temperature of about 2iO~7.
Longer residence times can be used if desir~d or process control purposes. A vapor stream containing e~Jolv~d moisture and oxygen is withdrawn at 19. The resulting coal/oil slurry mixture at 17 which has appreciably reduced moisture and oxygen content, is pressurized at 20 and passed as stream 21 to a coal liquefaction process 24.
The temperature controlled slurry mixing tank 14 for coal and recycle slurrying oils for direct coal liquefaction is operated at 250-650F temperature and 0-150 psig pres-sure. If desired, any fine inorganic solids which settle in the slurry mix tank, such as clay soLids from which water has been removed, can be withdrawn separately at 14b from the tank 14. Such withdrawal is facilitat~d by having a tapered bottom portion provided for the tank into which such fine deposits can collect. Whenever the pressure of slurry mix tank 14 is at or near atmospheric pressure, vapors evolved from the tank at 19 may be removed by an eductor device and are passed to a gas, oil and ~ater recovery system (not shown).
The dried and deoxygenated slurry from the mixing tank 14 is then usually pa~sed through a preheater 22 into a coal liquefaction process 24, which can be a catalytic or non-catalytic process. In the process, the reacted effluent material is separated into overhead and bottom streams, and the overhead mat~rial is separated into recycle gas, naphtha and distillate oil fractions. The bottoms are flashed iso-thermally to 50-150 psig pressure and passed to a liquid-solids separation step such as by a hydroclone device. A
gas stream is withdrawn at 25, light hydrocarbon liquid pro-duct at 26, and heavy hydrocarbon liquid product at 27. A
liquid stream 16 having 250-650F temperature is recycled to the slurrying tank 14 as the coal slurrying oil. ~ne ro~l-oil mixing tank will usually be adequately heated by recycl-ing the 'not 'nydroclone overflow stream to it as stream 16, however, additional heat such as from electric heaters can be provided as needed, such as for process start-up pur-poses. A portion of recycle gas will be flashed at the mixing tank presSurQ prior to pressuring the coal 'nopper and mixing tank.
Although the coal drying and deoxygenating step is usu-ally and preferably accomplished in a single mixing tank, two or even more staged tanks could be used each operated at increased temperature and pressure conditions. The coal-oil slurry from the first mixing tank-would be pumped into the subsequant tank for further heating, and the vapor streams evolved from the tanks would be passed to a recovery system (not shown).
The heating and drying coal-oil slurry step is pre-ferably used with a catalytic coal liquefaction process as shown in FIG. 2. In this preferred embodiment, the raw coal is crushed and sized similarly as for FIG 1 and introduced into hot slurry mix tank 14. From the hot slurrying mix tanX 14, the heated coal-oil slurry is pressurized by pump 20 to elevated pressure, such as 500-S000 psi, and is then passed through a preheater 22 into reac~or 30 containing catalyst bed 32. Recycled hydrogen at 28 can be reheated at 29 and provided to the reactor 30, together with fresh makeup hydrogen as needed at 28a, or alternatively can be passed as stream 28b to heater 22.
The coal-oil slurry and hydrogen streams then enter re-actor 30 contalning catalyst bed 32, passing uniformly up-wardly from the bottom -through flow distributor 31 at a flow rate and at temperature and pressure conditions to a~com-plish the desired hydrogenation reactions The catalyst in bed 32 should be selected from the group consisting of co-balt, iron, molybdenum, nickel, tin, and other hydrocarbon hydrogenation catalyst metals known in the art~ deposited on a base material selected from the group consisting of alu-mina, magnesia, silica, and similar materials. In addition, particulate hydrogenation catalyst may be added to rPactor 30 at connection 33 in the ratio of about 0.1 to 3.0 pounds of catalyst per ton of coal processed~
By concurrently flowing liquid and gasiform materials upwardly through the reactor containing a bed of solid par-ticles of specific catalyst as indicated above, and expand-ing the bed of solid particles by at least about 10%, and usually by 20 - 100~ over its settled height, the solid par-ticles are placed in random ebullated motion within the reactor by the upflowing streams. The characteristics of the ebullated bed at a particular degree of volume expansion can be such that finer, lighter particulate solids will pass upwardly ~hrough the catalyst bed, so that the contact par-ticles constituting the ebullated bed are retained in the reactor and the finer, lighter material pass from the reactor. The catalyst bed upper level 32a, above which few if any contact particles ascend, is the upper level of ebullation.
In general, the gross density of the mass of catalyst will be between about 25 to 200 pounds per cubic foot, the upward flow rate of the liquid will be between about 5 and 120 gallons per minute per square foot of horizontal cross-section area of the reactor, and the expanded volume of the ebullated bed usually will be not more t'nan double the volume of the settled mass. To maintain the desired super-ficial upward liquid velocity in the reactor, a portion of the liquid slurry is us~lally recycled to the reactor, such as llquid which is removed from above the upper level of ehullation 32a and recycled via downcomer conduit 34 and pump 35 to the bottom of the reactor 30, and then upwardly through flow distributor 31. Spent catalyst may be removed by drawoff at connection 36 to maintain the desired cataly-tic activity within the reaction zone.
Reactor operating conditions are maintained in the broad ranges o~ 700-930F temperature and 1000-5000 psi partial pressure of hydrogen, and preferably at 750-900F and 1000-4000 psi hydrogen partial pressure. Coal throughput or space velocity is in the range of 10 to 150 pounds coal per hour per cubic foot of reactor volume, so that the yield of unconverted coal as char is between about 4 and 10 W % of the moisture and ash-free coal feed. ~he relative size of the coal and catalyst particles and conditions of ebullation is such that catalyst is retained in the reactor while ash and unconverted coal or char particles are carried out with the liquid reaction products.
From reactor 30, an effluent stream 37 which is vir-tually free of solid catalyst particles is withdrawn, cooled at 38, and then passed to phase separator 40. From separa-tor 40, a light gas fraction stream is removed at 41 and passed to hydrogen purification step 42. A medium-purity hydrogen stream 43 is recovered from purification step 42, and recycled as stream 28 through heater 2~ to reactor 30 to provide a part of the hydrogen requirements therein as heated hydrogen s-tream 29a.
From separ~tor 40 a liquid fraction stream 44 is with-drawn, pressure-reduced at 45 and is passed to phase separa-tor 46~ This separator operates at near atmospheric pres-sure and 500-650F temperature and permits removal of a light hydrocarbon liquid stream at 47 and a heavy hydrocar-bon liquid ~tream at 48. Stream 47 contains naphtha and light distillate fractions and is passed o fractionation step 50, from which hydrocarbon gas p.-roducts are withdrawn at 51, light distillate product at 52 and m~dium distillate product at 53. m e hydrogenated f~ coal liquid fraction 48 u~ual~y having normal ~ iling range above about $50F and preerably 6Q0-950F and containing asphaltenes, preasphaltenes, unconverted coal and ash solids, is passed to liquid solids separation step 54, such as mult~ple hydroclones. An overflow 500F+ liquid stream containing reduced concentration of solids is removed at 56.
A portion 57 of liquid ~tream 56 is pas~ed to fractionator 50, and the remainder 5~ i~ pres~urized to reactor pressure at 59 and provides the slurrying oil 16 needed in slurry mix tank 14.
~~ . From separation step 54 underflow liquid ~tream 62, con-taining an incroased concentration of solids i~ removed and passed to vacuum distillation at 64. The resulting overhead liquid 65 from t~e vacuum still may be joined with stream 66 to provide a heavy distillate product stream 68. If dPsired, a por~ion of stream 68 can be used for slurrying oil 16. Also ~f desired, at least a portion 67 of the ~trealTI 66 can be passed to vacuum still 64. A he~vy vacuum bottoms stream 69 containing some asphaltenes, preasphalte-nes and unconverted coal and ash solids may be further pro-~G cessed by coking to recover oil product~, or by gasification to produce the makeup hydrogen need~d in the pr~cesC.
' ' 10 , .
4~
This invention will be further described 'cy reference f5 the following examples, which should not be construed as limiting in scope.
EX~MPLE _ Wyodak sub-bituminous particulate coal having 50-325 mesh particle size (U.S. Sieve Series) and containing 10-25 W ~ moisture was fed into a slurry mix tank maintained at a temperature range of 230-250F by hot hydrocarbon slurrying oil recycled to the tank from a coal liquefaction process unit. The initial moisture in the coal feed varied between 11 and 17.5 W ~, the residence time for the coal in the slurry tank was about 2 hours, and the water contained in the coal feed was substantially evaporated from the tanX as vapor. Averaged results of the slurry tank drying opera-tions over a period of several days are shown in Table 1.
WATER VAPORIZATION FROM COAL FEED IN SLURRY MIX TANK
_ _ Avg. Tank Temperature, F
Coal Feed Rate, lb/hx 211202 234 Slurrying Oil Feed, lb/hr 454429 428 Oil/Coal Weight Ratio 2.152.12 2.10 Initial Water in Slurry, W % Slurry6.5 5.S 4.0 Water in Slurry After Drying, W % Slurry 2.9 2.3 2.1 Water in Slurry, W % Coal 6.2 4.9 4.4 Water Removed by Slurry Tank, W % 45 42 52 These results show that even at the moderate slurry mix tank temperatures of 232-246F, between 42 and 52% of the moisture was removed from the coal feed initially containing 11-17,5 W % moisture down to about 4.4-6.2 W % of the dry coal. This dried coal-oil slurry material is suitable as a feedstream to a coal liquefaction process.
EX~PLE 2 A simulated slurry mixing tank stud~ of coal aeoxygena-tion was conducted in which the slurry consisted of r~7yodak coal containing 17-20 W % oxygen mixed with recycle oil derived from the Wyodak coal. The coal-oil slurry was treated in an autoclave at several temperatures between 350-500F and then analyzed. Results of coal deoxygenation and conversion vs. slurry tank temperature are shown in FIG.
and withdrawing a dried coal-oil slurry mixture containing reduced moisture and oxygen contents. By using the inven-tion, the water and oxygen content of the coal ~lurry are lowered and the relative reactivity of coal slurries con-taining bituminous and low rank sub-bituminous coals and similar organic deposits are increased by raising the coal-oil slurry temperature in tha slurry mixing vessel to at least about 240F and usually not exceeding about 650F.
Moisture remaining in the heated coal oil slurry is reduced to less than about 3 W ~, and the oxygen content is reduced to less than about 7 W ~. Also, a more reactive slurry is provided which produce~ a higher hydrogen partial pressure in the reactor and increases coal total conversion to pro-duct oils. At a given total reaction pressure, the inven-tion will improve product quality, and decrease energy requirements of cooling the recycle streams.
This coal drying and deoxygenation step is usually ac-complished in a single mixing vessel, however if desired, two or three staged mixing vessels can be use~ at increasing temperature and pressure conditions. Although this coal drying and deoxygenation step can be used to provide a dried coal-oil slurry stream as a fuel, it is preferably used as a pretreatment step for a coal feedstream to a coal liquefaction process~ and more pre~erably provides a feedstream to ~ catalytic coal liquefaction process.
Accordingly, when this coal drying and deox~genation step is used in a coal liquefaction process, it is intended to decrease H2 consumption, increase coal conversion, im-prove product quality, decrease the energy requirements of cooling the recycle streams, and thus improve the economics of direct coal liquefaction or for lignin upgrading. ~ne same beneits are also expected when processing coals con-taining higher concentrations of mineral matter and which contain clay water by decreasing or eliminating condensation reaction products caused by evolution of steam vapor from the clay.
_ _ _ _ FIG. 1 shows a schematic flow diagram of a process for drying and deoxygen~ting coal-oil slurry in accordance with the invention.
FIG. 2 shows a schematic flow diagram of the coal slurry dr~ing step operated upstream of a catalytic coal liquefac-tion process.
FIG. 3 ~hows two graphs of coal deoxygenation and con-version results from increasing slurry tank temperatures.
FIG. 4 shows a graph of decreasing yield of residual oil (975F+ fraction) for increasing slurry mixing tank temperature.
DESCRIPTION OF INVENTION
_ _ This invention will be further described as a coal pre~
treatment step for a coal liquefaction process. As shown in FIG. 1, raw coal at 10 is crushed or ground and screened at 12 to provide a particle size range of 30 375 mesh ~U. S, Sieve Serie-~). If desired, the coal can also be cleaned or beneficiated to remove mineral matter. The particulate coal a~ 13 is then fed into slurry mixing tank 14, where it is mixed with a hydrocarbon slurrying oil 16 having a norm~l boiling ran~e of about 500-750Fo The tank pressure is main-tained at 0-150 psig and preferably at 0-50 psig pre~ure by a portion of process-derived recycle gas stream. Th~ par-ticulate coal at 13 can be fed to the ~ixing vessel 14 through a conventional pres~urized lock hopper or via a screw or star type feeder (not show~)..
Effective mixing of the particulate coal and slurrying oil is achieved by providing a liquid velocity within the tank 14 of at least about 2 ft/sec. The coal and oil in the atmospheric pressure or pressurized mixing tank can be mixed by u~ing an angled agitator or mixer, baffle plate(s) and recycle circulation lines or ~imilar mechanical devices o provide a well mixed coal-oil slurry. Such mixing ~an be effectively provided either by a rotary mixer 15 mounted in the tank, or by the recycle to the tank of a portion 17a of slurry stream 17 by pump 18, or by both arrangements.
The slurry temperature in mixing tank 14 is maintained at 250-650F by recycling the hot slurryin~ oil 16 usually at about 550-700F temperature. Th~ slurry tank temperature is preferably 35Q-50QF. The tank 14 is usually provided with ~ternal thermal insulation 14a to conserve heat and heIp maintain the desired ~lurry temperature therein. The re~idence time for the coal in tank 14 will depend on the moi~ture content of th~ coal feed and the extent of drying de~ir~d, and u~ually ranges from about 0.2 hours at high drying.temper~ture of 650F and up to about 3 hours for high -moisture coals and lower drying temperature of about 2iO~7.
Longer residence times can be used if desir~d or process control purposes. A vapor stream containing e~Jolv~d moisture and oxygen is withdrawn at 19. The resulting coal/oil slurry mixture at 17 which has appreciably reduced moisture and oxygen content, is pressurized at 20 and passed as stream 21 to a coal liquefaction process 24.
The temperature controlled slurry mixing tank 14 for coal and recycle slurrying oils for direct coal liquefaction is operated at 250-650F temperature and 0-150 psig pres-sure. If desired, any fine inorganic solids which settle in the slurry mix tank, such as clay soLids from which water has been removed, can be withdrawn separately at 14b from the tank 14. Such withdrawal is facilitat~d by having a tapered bottom portion provided for the tank into which such fine deposits can collect. Whenever the pressure of slurry mix tank 14 is at or near atmospheric pressure, vapors evolved from the tank at 19 may be removed by an eductor device and are passed to a gas, oil and ~ater recovery system (not shown).
The dried and deoxygenated slurry from the mixing tank 14 is then usually pa~sed through a preheater 22 into a coal liquefaction process 24, which can be a catalytic or non-catalytic process. In the process, the reacted effluent material is separated into overhead and bottom streams, and the overhead mat~rial is separated into recycle gas, naphtha and distillate oil fractions. The bottoms are flashed iso-thermally to 50-150 psig pressure and passed to a liquid-solids separation step such as by a hydroclone device. A
gas stream is withdrawn at 25, light hydrocarbon liquid pro-duct at 26, and heavy hydrocarbon liquid product at 27. A
liquid stream 16 having 250-650F temperature is recycled to the slurrying tank 14 as the coal slurrying oil. ~ne ro~l-oil mixing tank will usually be adequately heated by recycl-ing the 'not 'nydroclone overflow stream to it as stream 16, however, additional heat such as from electric heaters can be provided as needed, such as for process start-up pur-poses. A portion of recycle gas will be flashed at the mixing tank presSurQ prior to pressuring the coal 'nopper and mixing tank.
Although the coal drying and deoxygenating step is usu-ally and preferably accomplished in a single mixing tank, two or even more staged tanks could be used each operated at increased temperature and pressure conditions. The coal-oil slurry from the first mixing tank-would be pumped into the subsequant tank for further heating, and the vapor streams evolved from the tanks would be passed to a recovery system (not shown).
The heating and drying coal-oil slurry step is pre-ferably used with a catalytic coal liquefaction process as shown in FIG. 2. In this preferred embodiment, the raw coal is crushed and sized similarly as for FIG 1 and introduced into hot slurry mix tank 14. From the hot slurrying mix tanX 14, the heated coal-oil slurry is pressurized by pump 20 to elevated pressure, such as 500-S000 psi, and is then passed through a preheater 22 into reac~or 30 containing catalyst bed 32. Recycled hydrogen at 28 can be reheated at 29 and provided to the reactor 30, together with fresh makeup hydrogen as needed at 28a, or alternatively can be passed as stream 28b to heater 22.
The coal-oil slurry and hydrogen streams then enter re-actor 30 contalning catalyst bed 32, passing uniformly up-wardly from the bottom -through flow distributor 31 at a flow rate and at temperature and pressure conditions to a~com-plish the desired hydrogenation reactions The catalyst in bed 32 should be selected from the group consisting of co-balt, iron, molybdenum, nickel, tin, and other hydrocarbon hydrogenation catalyst metals known in the art~ deposited on a base material selected from the group consisting of alu-mina, magnesia, silica, and similar materials. In addition, particulate hydrogenation catalyst may be added to rPactor 30 at connection 33 in the ratio of about 0.1 to 3.0 pounds of catalyst per ton of coal processed~
By concurrently flowing liquid and gasiform materials upwardly through the reactor containing a bed of solid par-ticles of specific catalyst as indicated above, and expand-ing the bed of solid particles by at least about 10%, and usually by 20 - 100~ over its settled height, the solid par-ticles are placed in random ebullated motion within the reactor by the upflowing streams. The characteristics of the ebullated bed at a particular degree of volume expansion can be such that finer, lighter particulate solids will pass upwardly ~hrough the catalyst bed, so that the contact par-ticles constituting the ebullated bed are retained in the reactor and the finer, lighter material pass from the reactor. The catalyst bed upper level 32a, above which few if any contact particles ascend, is the upper level of ebullation.
In general, the gross density of the mass of catalyst will be between about 25 to 200 pounds per cubic foot, the upward flow rate of the liquid will be between about 5 and 120 gallons per minute per square foot of horizontal cross-section area of the reactor, and the expanded volume of the ebullated bed usually will be not more t'nan double the volume of the settled mass. To maintain the desired super-ficial upward liquid velocity in the reactor, a portion of the liquid slurry is us~lally recycled to the reactor, such as llquid which is removed from above the upper level of ehullation 32a and recycled via downcomer conduit 34 and pump 35 to the bottom of the reactor 30, and then upwardly through flow distributor 31. Spent catalyst may be removed by drawoff at connection 36 to maintain the desired cataly-tic activity within the reaction zone.
Reactor operating conditions are maintained in the broad ranges o~ 700-930F temperature and 1000-5000 psi partial pressure of hydrogen, and preferably at 750-900F and 1000-4000 psi hydrogen partial pressure. Coal throughput or space velocity is in the range of 10 to 150 pounds coal per hour per cubic foot of reactor volume, so that the yield of unconverted coal as char is between about 4 and 10 W % of the moisture and ash-free coal feed. ~he relative size of the coal and catalyst particles and conditions of ebullation is such that catalyst is retained in the reactor while ash and unconverted coal or char particles are carried out with the liquid reaction products.
From reactor 30, an effluent stream 37 which is vir-tually free of solid catalyst particles is withdrawn, cooled at 38, and then passed to phase separator 40. From separa-tor 40, a light gas fraction stream is removed at 41 and passed to hydrogen purification step 42. A medium-purity hydrogen stream 43 is recovered from purification step 42, and recycled as stream 28 through heater 2~ to reactor 30 to provide a part of the hydrogen requirements therein as heated hydrogen s-tream 29a.
From separ~tor 40 a liquid fraction stream 44 is with-drawn, pressure-reduced at 45 and is passed to phase separa-tor 46~ This separator operates at near atmospheric pres-sure and 500-650F temperature and permits removal of a light hydrocarbon liquid stream at 47 and a heavy hydrocar-bon liquid ~tream at 48. Stream 47 contains naphtha and light distillate fractions and is passed o fractionation step 50, from which hydrocarbon gas p.-roducts are withdrawn at 51, light distillate product at 52 and m~dium distillate product at 53. m e hydrogenated f~ coal liquid fraction 48 u~ual~y having normal ~ iling range above about $50F and preerably 6Q0-950F and containing asphaltenes, preasphaltenes, unconverted coal and ash solids, is passed to liquid solids separation step 54, such as mult~ple hydroclones. An overflow 500F+ liquid stream containing reduced concentration of solids is removed at 56.
A portion 57 of liquid ~tream 56 is pas~ed to fractionator 50, and the remainder 5~ i~ pres~urized to reactor pressure at 59 and provides the slurrying oil 16 needed in slurry mix tank 14.
~~ . From separation step 54 underflow liquid ~tream 62, con-taining an incroased concentration of solids i~ removed and passed to vacuum distillation at 64. The resulting overhead liquid 65 from t~e vacuum still may be joined with stream 66 to provide a heavy distillate product stream 68. If dPsired, a por~ion of stream 68 can be used for slurrying oil 16. Also ~f desired, at least a portion 67 of the ~trealTI 66 can be passed to vacuum still 64. A he~vy vacuum bottoms stream 69 containing some asphaltenes, preasphalte-nes and unconverted coal and ash solids may be further pro-~G cessed by coking to recover oil product~, or by gasification to produce the makeup hydrogen need~d in the pr~cesC.
' ' 10 , .
4~
This invention will be further described 'cy reference f5 the following examples, which should not be construed as limiting in scope.
EX~MPLE _ Wyodak sub-bituminous particulate coal having 50-325 mesh particle size (U.S. Sieve Series) and containing 10-25 W ~ moisture was fed into a slurry mix tank maintained at a temperature range of 230-250F by hot hydrocarbon slurrying oil recycled to the tank from a coal liquefaction process unit. The initial moisture in the coal feed varied between 11 and 17.5 W ~, the residence time for the coal in the slurry tank was about 2 hours, and the water contained in the coal feed was substantially evaporated from the tanX as vapor. Averaged results of the slurry tank drying opera-tions over a period of several days are shown in Table 1.
WATER VAPORIZATION FROM COAL FEED IN SLURRY MIX TANK
_ _ Avg. Tank Temperature, F
Coal Feed Rate, lb/hx 211202 234 Slurrying Oil Feed, lb/hr 454429 428 Oil/Coal Weight Ratio 2.152.12 2.10 Initial Water in Slurry, W % Slurry6.5 5.S 4.0 Water in Slurry After Drying, W % Slurry 2.9 2.3 2.1 Water in Slurry, W % Coal 6.2 4.9 4.4 Water Removed by Slurry Tank, W % 45 42 52 These results show that even at the moderate slurry mix tank temperatures of 232-246F, between 42 and 52% of the moisture was removed from the coal feed initially containing 11-17,5 W % moisture down to about 4.4-6.2 W % of the dry coal. This dried coal-oil slurry material is suitable as a feedstream to a coal liquefaction process.
EX~PLE 2 A simulated slurry mixing tank stud~ of coal aeoxygena-tion was conducted in which the slurry consisted of r~7yodak coal containing 17-20 W % oxygen mixed with recycle oil derived from the Wyodak coal. The coal-oil slurry was treated in an autoclave at several temperatures between 350-500F and then analyzed. Results of coal deoxygenation and conversion vs. slurry tank temperature are shown in FIG.
3. It was noted that as the slurry tank temperature was increased from about 230F up to 500F, increased deoxygenation and decarboxylation of the coal occurred and the treated slurry became relatively more reactive, as indi-cated by the increased coal conversion achieved. It is believed that the more reactive slurry was produced due to the loss of carboxyl and water molecules contained in the coal. A more reactive slurry for direct coal liquefaction not only increases coal conversion, but is believed to also change the yield distribution favorably to produce more low boiling hydrocarbon liquid fractions. Also, the hydrogen partial pressure in a hydrogenation reactor would increase due ~o the loss of carbon dioxide and water molecules from the slurry mix tank instead of their remaining in the reac-tor feed stream.
EX~MPLE 3 Illinois No. 6 bituminous coal initially containing about io w ~ moisture and having particle size range of 50-200 mesh (U.S. Sieve Series) was mixed with a recycled csal-derived oil in a ratio in the range of 1.~-1.8. The recycled oil temperature was 450-600F. Initial mixing of the coal and oil occurred in a tank at 160-200F temperature for 3 hours average residence time to produce a slurr-~source and to remove a substantial portion of the moisture from the coal. The resulting coal/oil slurry was then transferred into a second mixing tank maintained at a constant slurry level and in which the mixing temperature was maintained at 450F by electric heaters for an average residence time of 1.9 hours. The remaining oxygen contained in the coal was evolved from the second mix tank and a vapor stream was removed containing moisture and oxygen. The re-sulting coal/oil slurry stream containing reduced moisture and oxygen content was withdrawn from -the lower end of the tank.
The reactivity o the heated coal-oil slurry was deter-mined by microautoclave analysis. Samples of the coal-oil slurry were obtained before and after treatment in the hot slurry mix tank, and the slurry material was then reacted thermally in a microautoclave at 850F for 30 minutes. The resulting reacted material was then extracted separat~ly with cyclohexane, with toluene, and with tetrahydroEuran (THF), and results are shown in Table 2.
CONVERSION OF ILLINOIS NO. 6 COAL~OIL SLURRY, W % SLURRY
Before After Solvent Used Coal Treatment Coal Treatment*
Cyclohexane 57.9 64.3 Toluene ~1.0 66.5 THF 80.3 84.1 At 450F for 1.9 hours Based on the above results, it is noted that an incrG~se in slurry reactivity occurred with increased slurry ~ix tar.~
temperature of 450F. Thus, the solubility and reactivity of the coal/oil slurry was increased, as shown by the increased conversion of the coal achieved at otherwise equivalent reaction conditions.
EX~MPLE 4 Illinois No. 6 bituminous coal similar to that in Exam-ple 3 was mixed with a coal-derived hydrocarbon liquid or slurrying oil in a coal/oil ratio in the range of 1.6-1. a .
The recycled oil temperature was 450-600F. Initial mixing of the particulate coal and oil occurred in a tank at 160-200F temperature for 3 hours average residence time for the coal. The resulting mixed coal/oil slurry was then transferred into a second mixing tank in which the mixing temperature was maintained at 450F by means of electric heaters and in which the average residence time for the coal was 1.9 hours. Moisture and oxygen originally contained in the coal were evolved from the second slurry mixing tank and a vapor stream was removed containing moisture and oxygen, The resulting coal/oil slurry containing reduced moisture and oxygen was withdrawn from the tank and passed to a bench scale coal catalytic hydrogenation process. Operating con-ditions for the process and results achieved are shown in Table 3 and also in FIG. 4.
COMPARATIVE LIQUEFACTION PROCESS PEP~ORMANCE ~JS.
_ . __ _ SLURRY MIX TANK TEMPERATURE
Conventional Operation Per Operation This Invention Slurry Mix Tank Temp. F 250 450 Moisture in coal, W % 10 10 Reaction Conditions Temperaturë, F 850 850 Total Pressure, psi~2250 2250 Feed Rate, lb/hr/ft~31.2 31.2 Catalyst Age, lb coal/lb cat. 1400 1400 Yields, W % of Coal Feed Cl-C3 Gas -- 8 . 5 C4-400F Naphtha - 20.3 20.5 400-975F Distillate 31.6 35 8 975F+ Residuum 14.6 10.8 Unconverted Coal 4.4 5.1 Ash 11.5 11.5 Water 8.9 9.4 CO~CO2 0.8 0.4 NH3~H2S 3.3 3 5 C4-975F Material 51.8 56.3 Coal Conversion, W % M.A.F. Coal 95.094.3 It is noted that as the-slurry mix tank temperature was increased from 250F to 450F during an 8-day period of operation, the yield of 400-975F fraction increased from 31.6 to 35.8 W %ras shown in Table 3. Also, during this ime, the residual oil produc-t yield (975F+ fraction) dry decreased from 14.6 to 10.8 W % of/ coal feed for otherwise equivalent operating conditions. Also, the decrease in CO
and CO2 in the product yields from the liquefaction at the higher slurry mix tank temperature indicates that increased oxygen was removed from the coal in the hot slurry mix tank.
S~ch decrease in residual oil yields with increasing slurry mix tank temperature is further shown in FIG~ 4.
Wyodak sub-bituminous coal initially containing abou~
14-17 W % moisture ~nd 17-19 W % oxygen and having particle si~e of 50~200 mesh (U.S. Sieve Series~ is mi~ed wi~h an oil derived from the coal in a liquefac~ion and hydrogena-tion process. The oil temperature used is ~50-600F and the weigh~ ratio of oil to coal is 105-1.6, The coal/oil mix-ture is maintained at a temperature of about 450F by elec-tric heaters for an verage coal residence time of 1.9 0 hours.
Moisture and oxy~en contained in the coal re èvolYed from the mix tank and a vapor strea~. removed containing moi~ture and oxygen. The resulting coal/oil slurry csn7 taining a substantially reduced concentrat.ion of both mois-ture and oxygen are withdrawn from the hot slurry mix tank and fed to a coal liquefaction process for producing hydro-carbon liquid product~ while requirin~ reduced hydrogen consump~ion as compared ~o a liquefaction process having conventional slurry mix tank temperature of ~00-250F.
Although this invention has been described broadly and in terms sf certain preferred embodiments, it will be understood ~at modifications and variations to the.process can be made within the ~pirit and ~cope of the invention, which is defined by the following claims.
EX~MPLE 3 Illinois No. 6 bituminous coal initially containing about io w ~ moisture and having particle size range of 50-200 mesh (U.S. Sieve Series) was mixed with a recycled csal-derived oil in a ratio in the range of 1.~-1.8. The recycled oil temperature was 450-600F. Initial mixing of the coal and oil occurred in a tank at 160-200F temperature for 3 hours average residence time to produce a slurr-~source and to remove a substantial portion of the moisture from the coal. The resulting coal/oil slurry was then transferred into a second mixing tank maintained at a constant slurry level and in which the mixing temperature was maintained at 450F by electric heaters for an average residence time of 1.9 hours. The remaining oxygen contained in the coal was evolved from the second mix tank and a vapor stream was removed containing moisture and oxygen. The re-sulting coal/oil slurry stream containing reduced moisture and oxygen content was withdrawn from -the lower end of the tank.
The reactivity o the heated coal-oil slurry was deter-mined by microautoclave analysis. Samples of the coal-oil slurry were obtained before and after treatment in the hot slurry mix tank, and the slurry material was then reacted thermally in a microautoclave at 850F for 30 minutes. The resulting reacted material was then extracted separat~ly with cyclohexane, with toluene, and with tetrahydroEuran (THF), and results are shown in Table 2.
CONVERSION OF ILLINOIS NO. 6 COAL~OIL SLURRY, W % SLURRY
Before After Solvent Used Coal Treatment Coal Treatment*
Cyclohexane 57.9 64.3 Toluene ~1.0 66.5 THF 80.3 84.1 At 450F for 1.9 hours Based on the above results, it is noted that an incrG~se in slurry reactivity occurred with increased slurry ~ix tar.~
temperature of 450F. Thus, the solubility and reactivity of the coal/oil slurry was increased, as shown by the increased conversion of the coal achieved at otherwise equivalent reaction conditions.
EX~MPLE 4 Illinois No. 6 bituminous coal similar to that in Exam-ple 3 was mixed with a coal-derived hydrocarbon liquid or slurrying oil in a coal/oil ratio in the range of 1.6-1. a .
The recycled oil temperature was 450-600F. Initial mixing of the particulate coal and oil occurred in a tank at 160-200F temperature for 3 hours average residence time for the coal. The resulting mixed coal/oil slurry was then transferred into a second mixing tank in which the mixing temperature was maintained at 450F by means of electric heaters and in which the average residence time for the coal was 1.9 hours. Moisture and oxygen originally contained in the coal were evolved from the second slurry mixing tank and a vapor stream was removed containing moisture and oxygen, The resulting coal/oil slurry containing reduced moisture and oxygen was withdrawn from the tank and passed to a bench scale coal catalytic hydrogenation process. Operating con-ditions for the process and results achieved are shown in Table 3 and also in FIG. 4.
COMPARATIVE LIQUEFACTION PROCESS PEP~ORMANCE ~JS.
_ . __ _ SLURRY MIX TANK TEMPERATURE
Conventional Operation Per Operation This Invention Slurry Mix Tank Temp. F 250 450 Moisture in coal, W % 10 10 Reaction Conditions Temperaturë, F 850 850 Total Pressure, psi~2250 2250 Feed Rate, lb/hr/ft~31.2 31.2 Catalyst Age, lb coal/lb cat. 1400 1400 Yields, W % of Coal Feed Cl-C3 Gas -- 8 . 5 C4-400F Naphtha - 20.3 20.5 400-975F Distillate 31.6 35 8 975F+ Residuum 14.6 10.8 Unconverted Coal 4.4 5.1 Ash 11.5 11.5 Water 8.9 9.4 CO~CO2 0.8 0.4 NH3~H2S 3.3 3 5 C4-975F Material 51.8 56.3 Coal Conversion, W % M.A.F. Coal 95.094.3 It is noted that as the-slurry mix tank temperature was increased from 250F to 450F during an 8-day period of operation, the yield of 400-975F fraction increased from 31.6 to 35.8 W %ras shown in Table 3. Also, during this ime, the residual oil produc-t yield (975F+ fraction) dry decreased from 14.6 to 10.8 W % of/ coal feed for otherwise equivalent operating conditions. Also, the decrease in CO
and CO2 in the product yields from the liquefaction at the higher slurry mix tank temperature indicates that increased oxygen was removed from the coal in the hot slurry mix tank.
S~ch decrease in residual oil yields with increasing slurry mix tank temperature is further shown in FIG~ 4.
Wyodak sub-bituminous coal initially containing abou~
14-17 W % moisture ~nd 17-19 W % oxygen and having particle si~e of 50~200 mesh (U.S. Sieve Series~ is mi~ed wi~h an oil derived from the coal in a liquefac~ion and hydrogena-tion process. The oil temperature used is ~50-600F and the weigh~ ratio of oil to coal is 105-1.6, The coal/oil mix-ture is maintained at a temperature of about 450F by elec-tric heaters for an verage coal residence time of 1.9 0 hours.
Moisture and oxy~en contained in the coal re èvolYed from the mix tank and a vapor strea~. removed containing moi~ture and oxygen. The resulting coal/oil slurry csn7 taining a substantially reduced concentrat.ion of both mois-ture and oxygen are withdrawn from the hot slurry mix tank and fed to a coal liquefaction process for producing hydro-carbon liquid product~ while requirin~ reduced hydrogen consump~ion as compared ~o a liquefaction process having conventional slurry mix tank temperature of ~00-250F.
Although this invention has been described broadly and in terms sf certain preferred embodiments, it will be understood ~at modifications and variations to the.process can be made within the ~pirit and ~cope of the invention, which is defined by the following claims.
Claims (18)
1. A process for drying and deoxygenating particulate coal to remove moisture and oxygen contained therein, comprising the steps of:
(a) mixing a particulate coal feed with a hydrocarbon slurrying oil in a mixing zone to provide a coal-oil slurry mixture having an oil/coal ratio of from about 1.2 to about 2.5;
(b) heating said coal-oil slurry mixture to 230-650°F
temperature to evolve moisture and oxygen vapors from the coal; and (c) withdrawing a dried coal-oil slurry mixture con-taining reduced moisture and oxygen contents
(a) mixing a particulate coal feed with a hydrocarbon slurrying oil in a mixing zone to provide a coal-oil slurry mixture having an oil/coal ratio of from about 1.2 to about 2.5;
(b) heating said coal-oil slurry mixture to 230-650°F
temperature to evolve moisture and oxygen vapors from the coal; and (c) withdrawing a dried coal-oil slurry mixture con-taining reduced moisture and oxygen contents
2. The process of claim 1, wherein said particulate coal feed initially contains 5-30 W % moisture.
3. The process of claim 1, wherein said coal feed has a particle size of 30-375 mesh (U.S. Sieve Series).
4. The process of claim 1, wherein said slurrying oil is derived from a coal liquefaction process and has a tem-perature of 500-675°F prior to said mixing with the par-ticulate coal.
5. The process of claim 1, wherein the coal-oil slurry temperature is maintained at 250-650°F temperature during the mixing step (a).
6. The process of claim 1, wherein said mixing of the coal and slurrying oil occurs at 0-150 psig pressure.
7. The process of claim 4, wherein the slurrying oil contains at least about 10 W % particulate solids consisting essentially of unconverted coal and mineral matter.
8. The process of claim 1, wherein inorganic solids are withdrawn separately from the mixing zone.
9. The process of claim 1, wherein the coal feed is bituminous coal containing 5-15 W % moisture.
10. The process of claim 1, wherein the coal feed is sub-bituminous coal containing 10-30 W % moisture.
11. The process of claim 1, wherein the coal feed is lignite containing 15-35 W % moisture.
12. The process of claim 1, wherein said coal-oil mixing is sufficient to produce liquid velocities within said mixing zone of at least about 2 ft/sec.
13. The process of claim 1, wherein the coal residence time in said mixing zone is from about 1 to about 3 hours.
14. The process of claim 1, wherein said dried and deoxygenated coal-oil slurry mixture contains less than about 3 W % moisture and less than about 7 W % oxygen.
15. The process of claim 4, wherein hydrocarbon slurrying oil is at least partially hydroclone overhead liquid recycled from said coal liquefaction process.
16. The process of claim 1, wherein said heated coal-oil slurry mixture is fed into a coal liquefaction process, and increasing the temperature of the coal-oil slurry mix-ture from about 240°F to about 650°F results in increased conversion of the coal feed to hydrocarbon liquid and gas products in the coal liquefaction process.
17. A process for drying and deoxygenating particulate coal to remove moisture and oxygen contained therein, comprising the steps of:
(a) mixing a particulate coal feed initially containing 5-30 W % moisture with a hydrocarbon slurrying oil in a mixing zone maintained at 0-150 psig pressure to provide a coal-oil slurry mixture having an oil/coal ratio of from about 1.2 to about 2.5;
(b) heating said coal-oil slurry mixture to 230-650°F
temperature with a slurrying oil derived from a coal liquefaction process, said oil having a tem-perature of 500-675°F to evolve moisture and oxygen from the coal; and (c) withdrawing a dried and deoxygenated coal-oil slurry mixture containing less than about 3.0 W %
moisture and less than about 7 W % oxygen.
(a) mixing a particulate coal feed initially containing 5-30 W % moisture with a hydrocarbon slurrying oil in a mixing zone maintained at 0-150 psig pressure to provide a coal-oil slurry mixture having an oil/coal ratio of from about 1.2 to about 2.5;
(b) heating said coal-oil slurry mixture to 230-650°F
temperature with a slurrying oil derived from a coal liquefaction process, said oil having a tem-perature of 500-675°F to evolve moisture and oxygen from the coal; and (c) withdrawing a dried and deoxygenated coal-oil slurry mixture containing less than about 3.0 W %
moisture and less than about 7 W % oxygen.
18. A process for drying and deoxygenating particulate coal to remove moisture and oxygen contained therein, comprising the steps of:
(a) mixing a particulate coal feed initially containing 5-30 W % moisture with a hydrocarbon slurrying oil in a mixing zone maintained at 0-150 psig pressure to provide a coal-oil slurry mixture having an oil/coal ratio of from about 1.2 to about 2.5;
(b) heating said coal-oil slurry mixture to 230-650°F
temperature with a slurrying oil derived from a coal liquefaction process, said oil having a tem-perature of 500-675 °F to evolve moisture and oxygen from the coal; and (c) withdrawing a dried and deoxygenated coal-oil slurry mixture from said mixing zone; and (d) feeding the slurry to a catalytic coal liquefaction process wherein increasing the temperature of the coal-oil slurry from about 240°F to about 650°F
results in increased conversion of the coal to hydrocarbon liquid and gas products in the coal liquefaction process.
(a) mixing a particulate coal feed initially containing 5-30 W % moisture with a hydrocarbon slurrying oil in a mixing zone maintained at 0-150 psig pressure to provide a coal-oil slurry mixture having an oil/coal ratio of from about 1.2 to about 2.5;
(b) heating said coal-oil slurry mixture to 230-650°F
temperature with a slurrying oil derived from a coal liquefaction process, said oil having a tem-perature of 500-675 °F to evolve moisture and oxygen from the coal; and (c) withdrawing a dried and deoxygenated coal-oil slurry mixture from said mixing zone; and (d) feeding the slurry to a catalytic coal liquefaction process wherein increasing the temperature of the coal-oil slurry from about 240°F to about 650°F
results in increased conversion of the coal to hydrocarbon liquid and gas products in the coal liquefaction process.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US43759482A | 1982-10-29 | 1982-10-29 | |
| US437,594 | 1982-10-29 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1214419A true CA1214419A (en) | 1986-11-25 |
Family
ID=23737086
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000439947A Expired CA1214419A (en) | 1982-10-29 | 1983-10-28 | Coal slurry and deoxygenating process for coal liquefaction |
Country Status (6)
| Country | Link |
|---|---|
| JP (1) | JPS59108087A (en) |
| AU (1) | AU569480B2 (en) |
| CA (1) | CA1214419A (en) |
| DE (1) | DE3339139A1 (en) |
| GB (1) | GB2129438B (en) |
| ZA (1) | ZA837887B (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA1183349A (en) * | 1983-02-22 | 1985-03-05 | Brian Y. Wong | Beneficiation of low-rank coals by immersion in residuum |
| JPH04122934U (en) * | 1991-04-18 | 1992-11-05 | 株式会社富士通ゼネラル | oil hot water boiler |
| AU668328B2 (en) * | 1993-12-27 | 1996-04-26 | Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel Ltd) | Solid fuel made from porous coal and production process and production apparatus therefore |
| JP4586783B2 (en) * | 2006-09-22 | 2010-11-24 | 東洋インキ製造株式会社 | Photosensitive coloring composition and color filter |
| CN101987962B (en) * | 2010-11-12 | 2014-01-15 | 煤炭科学研究总院 | Method for liquefying high-oxygen content coal by adopting direct hydrogenation |
Family Cites Families (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1925005A (en) * | 1926-03-25 | 1933-08-29 | Koppers Co Inc | Coal treatment process |
| GB309231A (en) * | 1928-08-13 | 1929-04-11 | William Mcintyre Cranston | Improvements relating to the low temperature carbonisation of coal |
| GB407360A (en) * | 1932-07-09 | 1934-03-09 | John Lloyd Strevens | Improvements in or relating to the extraction of oil from solid fuels, shales, torbanites and the like |
| GB449619A (en) * | 1934-12-31 | 1936-06-30 | Nelson Consitt | Improvements in or relating to distilling and coking mixtures of solid carbonaceous materials and hydrocarbon oils |
| GB446357A (en) * | 1935-01-21 | 1936-04-29 | Erwin Bluemner | Process of and apparatus for the production of a truly colloidal fuel |
| GB547029A (en) * | 1940-10-16 | 1942-08-11 | Reginald Percy Fraser | Improvements relating to combustible mixtures of liquid and pulverized solid materials |
| GB779901A (en) * | 1954-08-06 | 1957-07-24 | Erwin Bluemner | Improvements relating to the cracking of coal oil mixtures |
| GB975687A (en) * | 1962-04-27 | 1964-11-18 | British Petroleum Co | Improvements relating to the preparation of coal-oil slurries |
| US4209911A (en) * | 1978-09-22 | 1980-07-01 | Hydrocarbon Research, Inc. | Method and apparatus for drying a moisture-containing particulate material |
| JPS5543037A (en) * | 1978-09-25 | 1980-03-26 | Nisshinbo Ind Inc | Concentrated lime sulfur mixture |
| JPS56147888A (en) * | 1980-04-18 | 1981-11-17 | Mitsui Cokes Kogyo Kk | Liquefaction of water-containing coals |
| JPS6032668B2 (en) * | 1980-09-19 | 1985-07-29 | 電源開発株式会社 | Liquefaction method of lignite |
| US4400261A (en) * | 1981-10-05 | 1983-08-23 | International Coal Refining Company | Process for coal liquefaction by separation of entrained gases from slurry exiting staged dissolvers |
| GB2114591B (en) * | 1982-02-08 | 1985-10-23 | Pittsburgh Midway Coal Mining | Method for coal feed slurry preparation |
| US4397732A (en) * | 1982-02-11 | 1983-08-09 | International Coal Refining Company | Process for coal liquefaction employing selective coal feed |
-
1983
- 1983-10-20 GB GB08328089A patent/GB2129438B/en not_active Expired
- 1983-10-24 ZA ZA837887A patent/ZA837887B/en unknown
- 1983-10-25 AU AU20545/83A patent/AU569480B2/en not_active Ceased
- 1983-10-28 CA CA000439947A patent/CA1214419A/en not_active Expired
- 1983-10-28 DE DE19833339139 patent/DE3339139A1/en not_active Withdrawn
- 1983-10-29 JP JP58201932A patent/JPS59108087A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| GB8328089D0 (en) | 1983-11-23 |
| AU2054583A (en) | 1984-05-03 |
| AU569480B2 (en) | 1988-02-04 |
| ZA837887B (en) | 1984-06-27 |
| DE3339139A1 (en) | 1984-05-03 |
| GB2129438B (en) | 1987-04-29 |
| JPS59108087A (en) | 1984-06-22 |
| JPH047399B2 (en) | 1992-02-10 |
| GB2129438A (en) | 1984-05-16 |
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