JPS60173089A - Two step coal liquefaction - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Background of the invention The present invention relates to a method for liquefying coal.

In particular, it concerns a two-step process of hydrothermal and catalytic hydroliquefaction of granulated coal in a slurry with a solvent.

It is well known to hydrogenate a slurry of coal and solvent at high temperature and pressure in the presence of a hydrogenation catalyst to produce a liquid product. These properties present significant hindrances in the subsequent processing required, e.g., fines removal and/or catalytic hydrocracking.Rosenthal and Dahlberg have shown that granulated coal is F fully dissolved in the solvent in the presence of hydrogen and all effluents from the dissolution stage (gases, liquids and solids) are below the temperature of the dissolution zone and below 800''F. A two-stage process for the liquefaction of coal directly to a hydrocracking zone (U.S. Pat. No. 4.330.3).
No. 91) was found. This method requires an A of at least -6
A product with a specific gravity of PI is provided in high yield. In one embodiment, this process is known in the industry as "'ccLp," which stands for Chevron Coal Liquefaction Process.

In one preferred embodiment of COLP, the dissolution device and the contact reactor are tightly connected. Separation of solids occurs downstream of the reactor. The coal conversion rate and distillate yield are maximized. Product viscosity.

degree is low (as a result, solids separation is easier,
It can be done in a mixed state. After all, the melting equipment operates under more severe conditions, and at the stage of the hydrothermal melting equipment.

More decomposition products and lactic gases were produced. In addition, the distillate produced in the dissolver was further hydrogenated in a catalytic reactor, which improved the properties of the product but led to a further increase in hydrogen consumption.

In the high-temperature hydrothermal melting equipment that characterizes GOLP, an unstable mixture is formed with the remaining heavy undecomposed substances, which are considered to be mostly aromatic and some unsaturated, resulting in a saturated light product. generate things. The heavy portion of the liquor from coal contains asphaltenes which require aromatic carriers to dissolve.

Even if the substance alone may not have sufficient rinsing power,
To keep undecomposed heavier asphaltenes in solution, adding a solvent may increase the dissolving power through interaction. As a result, phase separation and asphaltene precipitation may occur as the temperature decreases from the dissolver stage to the lower temperature hydrocracking stage. US Patent No. 4
, 330.393, the physical structure of the dissolution zone is as follows:
In this area, the slurry is allowed to flow upward or downward.

U.S. Air Force 4! In the multi-stage coal liquefaction method of No. 411101192, it is advantageous to pass hydrogen and liquid in parallel from the melting zone to the contact treatment zone in the middle of the melting zone, while removing most of the waste from the melting zone. has been discovered.

The preferred embodiment of ICLF produces the most hydrogenated product of all the major coal liquefaction processes.

The product of CCLP has a higher hydrogen content throughout the boiling fraction and especially in the middle distillate region. While other coal mining processes cannot accept heavy fractions and solids upstream of the catalytic reactor (thus reducing liquid yield), CCLP, in its preferred embodiment, is the most The heavy components and solids are treated with a catalyst to obtain high efficiency. In this way, C0L
P is relatively high and requires more hydrogen. The hydrogen can be supplied in known manner from natural gas or coal. The cost of ccLp can be reduced without sacrificing its advantages if the following conditions are met:

The conditions are: (1) Light products that consume hydrogen in the catalytic reactor can be separated before the catalytic hydrocracking stage; beaten solids or heavy fractions are removed before the catalytic stage; and a slower operation than +m+ It is possible to choose the conditions.

It would be advantageous to improve the efficiency of hydrogen utilization in two-stage coal liquefaction processes, such as CICLP, by reducing the hydrogenation of the middle distillates of the two-stage process product. This could be achieved if the heavy fractions present in the middle distillates could be removed continuously at the dissolver stage.

The light product containing light saturated hydrocarbons found in the melter stage of the two-stage coal liquefaction process is water.

- Carbon oxides and other substances which cause instability and are harmful to the catalytic hydrogenolysis stage, if they can be continuously removed from the remaining liquid. Well, that would also be an advantage.

Using this method, the second stage would operate more efficiently and the product instability seen in asphaltene precipitation would be overcome. This and other advantages are achieved by the method of the present invention.

The present invention is a method for liquefying coal, which comprises mixing a solvent and granulated coal to form a coal solvent slurry.

In the hydrothermal decomposition-sdripping zone, the coal is sufficiently dissolved in the wetting agent to form a mixture consisting of solvent, molten coal, insoluble solids, and reformed products. on the other hand,
A light product, Tri-Bt, is stored from the mixture by simultaneously increasing the temperature and bringing the slurry into countercurrent contact with the first hydrogen gas stream. A gaseous stream consisting of light products is removed in a hydrothermal melting-slipping zone.

At least a substantial amount of undissolved solids in the residual mixture is contacted in the reaction zone with a second hydrogen gas stream and an externally supplied hydrocracking catalyst under hydrocracking conditions. An effluent stream having a portion that becomes liquid in the accelerated state is removed from the hydrocracking zone.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION In one preferred embodiment of the present invention, finely ground coal is slurried with a solvent in a coalescence zone. The effluent slurry from zone 10 is directed in line 15 to a hydrothermal melting-sdripping zone 20. The effluent slurry is in countercurrent contact, generally in a downward flow, with added hydrogen gas which enters the melt-striping zone 20 through line 25.

The slurry is heated to melt at least about 50 (by weight) 4'-cent coal in the presence of added hydrogen gas. This creates a mixture of solvent, molten coal, insoluble solids and light products. Hydrogen gas generally passes through zone 20 in an upward flow. A considerable amount of light product is then stripped from the mixture and removed from the melt-stripping zone via line 28.

The mixture from zone 20 is conducted through line 30 to zone 35 where it is cooled. At that time, it is preferable to
(below the temperature of the apparatus: 1 temperature, more preferably about 55°C to about 85°C below the temperature of the melter. Sometimes, some solids are removed from the mixture through line 36. The cooled mixture is then sent by line 40 to hydrocracking 'Hr Q 45, where it undergoes catalytic hydrocracking in the presence of hydrogen supplied by line 38. ,
It produces a relatively low viscosity liquid product that is easily separated from the remaining coal residue.

Referring to the figure in detail, the fine coal and solvent are mixed in zone 10 to form a pumpable slurry. In this invention, the basic raw material is solid granular coal, such as anthracite coal, al:blue coal, subtemperature coal, lignite, or a mixture thereof. Particularly preferred are bituminous and subbasinous coals.

The coal is produced by Tyler 5tand
Although it is also preferred that the coal be crushed and pulverized to a particle size smaller than 100 mesh, large particle coal may be processed in the present invention. The 6G agent used in zone 10 may be processed from and produced by any number of solvents known in the art of coal liquefaction technology.

Water IL-based bath additives are those known from the coal liquefaction technology, or are polycyclic aromatic compounds such as tetrahylonaphthalene or dihylonaphthalene, which can be at least partially combined with ionization. It consists of hydrocarbon water f. After hydrogenation, these solvents can donate or transfer the acquired hydrogen to hydrogen-deficient dissolved coal molecules.

In general, the best solvent can be obtained from many substances, including crude oil or a petroleum fraction with a boiling point of 200°C or higher, such as crude oil containing a lot of naphthenes distilled under atmospheric pressure; It is particularly preferred to use the vacuum distillation residue. Asphaltic or naphthenic crude oils are generally rich in aromatics and naphthenes when compared to paraffinic crude oils.

As a result, such crude oils are preferred over 7 and rough crude oils for use as solvents in the present invention. Such crude oil often contains paraffin-coated crude oil, yellow, odor, and metal-containing substances, which poses new problems when cleaning coffins. However, in the process of the present invention, higher metal contents can be achieved in the hydrocracking zone without prior demetalization or pretreatment precautions. % of the metals in the crude oil are combined with the coal residue suspended in the liquid feedstock, but are deposited and therefore are not deposited on the cracking catalyst.

It will be appreciated that suitable bath additives can be produced from a wide variety of raw materials, but on the other hand, the solvents obtained from the process, especially in the region of hydrocracking effluents, have a boiling point. 4
It is also preferred to use a portion of 00'F or higher.

The granulated coal has a 1-i ratio of solvent to coal of about 1:2 to about 5.
．． It is mixed with the solvent in a ratio of 0:1, preferably about 1=2 to about 5:1, more preferably about 1=1 to about 2:1. The slurry from zone 10 is processed using conventional methods (not shown), such as a 70-process heat exchanger, a steam evaporator (
It may be heated by a coil or a furnace. The slurry is fed or pumped along line 15 to a hydrothermal melting and dripping zone 20 consisting of one or more melting devices. In the melting device-stripping device, the slurry is
Approximately 40
0°C to 480°0 (750°F or l-1900°F
), preferably from about 425°C to 4°55°O (800°C
850°F (°F to 850°F) with added hydrogen. 1. Dry charcoal decalcification base blood. Coal of less than 50%, preferably 70% or more, most preferably 90% or more, is in Zone 2.
0, thereby forming a mixture of molten coal, cold bath solids and monolithic product. Ophthalmic products are organic gases, such as carbon oxides, light saturated F.
hydrogen oxides, such as methane, ethane, butane, and middle distillates (4j% ip4 up to about 670°0 (700°F)
It contains the more rodent fractions of hydrocarbon oils, including those commonly known as (boiling point) oils.

It is usually important that the slurry be heated to at least about 400°C (750°F) in order to dissolve 501 percent of the coal. In addition, the overall yield of liquid product at stand point will be considerably reduced.
I 1. To prevent thermal decomposition, 480°0 (9
It is usually required that the product not be heated to temperatures warmer than 00°F.

Hydrothermal melting) The IJ topping band J$, 20 basically consists of one or more elongated tubes.

The vessel preferably contains no externally added catalyst or contacting material, and the slurry flows downwardly in the zone (in one vessel, the hydrogen gas is mixed with the coal water in the heated slurry or bath). A vessel used for continuous contact of the mixture with hydrogen gas, designed to flow upward in countercurrent (contact) with the mixture resulting from hot melting, is filled with a solid packing. A column in which the mixture is sprayed into the column, an empty column through which the gas passes, or a column with many foam or pulp type trays, and the difference in concentration is In order to obtain the maximum driving force exerted on the unit and therefore the maximum velocity of de-sealing, e.g. in strippig, the gas and mixture will flow in sufficient countercurrent contact with each other. Design factors in operation are discussed in the 4th edition of the 5th edition of The Chemical Engineer's Handbook by Berry and Chilton, published by McGraw-Hill.
, Chapters 14 and 18 are incorporated herein in their entirety.

The hydrothermal melting-dripping zone 20 may also consist of one or more melting pipes in which the slurry and added hydrogen flow countercurrently or cocurrently. but,
It is assumed that at least 4% of the mixture of hydrothermal products of the coal-bath agent slurry is present in the hydrogen gas stream.
It is important that it consists of a stripping bath. Common understanding - A dripping tank is a liquid-filled tank with a level control mechanism to maintain a constant level of the liquid mixture in the tank and thus regulate the residence time of the mixture in the hydrothermal zone. It will be operated as a tank. Regarding level control,
The latter mode of operation is preferred under conditions where significant back-mixing is not detrimental to Norothes and its products, as exemplified by Berry and Chilton's No. 22 (see above), which are incorporated herein in their entirety. be. Preferably,
Common practice - The dripping vessel is preferably operated as a continuous multi-stage reactor of the vertical type (Berry and Chilton, supra, pp. 4-21), using the reactor internals described above. The latter mode of operation is preferred under claimed conditions characterized by back-mixing.

The yield profile of the product obtained from the hydrothermal melting-stripping tank zone 20 is such that the temperature of the zone 20 is stepped in series with temperature, i.e., the temperature near the entrance to zone 20 of line 15 is are arranged from the holding tank to a tank with a lower temperature near the outlet of the zone 20 of the line 30,
An improvement would be achieved if all temperatures in zone 20 fell within the aforementioned ranges. That is, under light standard conditions, the production of gaseous products is reduced. band 20
Decreasing the temperature towards the exit of zone 35 and 4
As in step 5, lower temperatures are preferred in subsequent stages, not only to prepare the mixture for it, but also to suppress the decomposition and decomposition reactions.Temperature control along the sequence of decomposition tanks. This can be easily achieved by intercooling between the tanks using a heat exchanger or a quench gas injection method.A similar effect can be achieved in the IJ Zubing zone 20 using the above-mentioned method. It can be obtained using a continuous multi-stage reactor. Internally multi-staged reactors that eliminate or reduce backmixing can be used, for example, by utilizing a descending preheated coal-magent slurry 15 and an ascending cooling hydrogen gas stream 25. - A gradually decreasing temperature distribution is obtained in the dripping tank. In another embodiment, hydrogen gas may be injected from the vertically elongated stripping zone (Id). In another embodiment, the temperature in the stripping zone is If staged and within the specified temperature range, a cooling step may not be necessary to obtain the lower temperature preferred for the hydrocracking step 45.

Given the operating conditions and the design factors described by those skilled in the art in mR, a countercurrent flow of hydrogen gas consisting of hydrogen flowing back in line 25, freshly supplied, and recycled hydrogen. is the amount of light product stripped and the normal boiling point of the light product stripped from the mixture,
Apply strips of mixture either deeply or shallowly. Virtually all gases, i.e., approximately 0°C (32'F')
Substances with lower normal boiling points can be dissolved in hydrothermal solutions 1.
Stripped from ripping band 20 and line 28
It is preferable that it be removed through a process. In other embodiments, about 2
It is also preferred that a significant amount of the total heavy fraction having a temperature point below 70 ff be stripped from the hydrothermal decomposition zone 20 and removed via line 28. Other sensitivity ranges from about 65 degrees Celsius to about 260 degrees Celsius.
Preferably, a substantial amount of all materials having normal boiling points below 100'F (100'F or even 500'F) are stripped from the hydrothermal stripping zone 20 and removed via line 28. In embodiments, a substantial amount of the middle distillate, i.e., the fraction boiling below about 260°0 (500F), is stripped, separated, and optionally recycled as a solvent. The light hydrocarbon products in the outgoing stream 28 should be fractionated and put to direct use; That will be further processed.

The operating conditions of the hydrothermal decomposition-sdripping zone can vary over a wide range, except for temperature, since the coal content is at least 50% by weight or more. Other reaction characteristics of the IJ wrapping zone include a residence time of about 0.01 to 6.0 hours, preferably about 0.1 hours.
to 1.0 hours: Pressure is approximately 0 to 10,000 psi
g, preferably about 1,500 to 5.000 psi
g, more preferably 1,500 to 2#500 psi
g ; Hydrogen gas amount is approximately 500 to 20,000 cubic feet (Nf) per barrel of slurry under standard conditions.
t3) (SCF/BBL), preferably 500
to 10,000 CF/BBL; most preferably about 500 to 4,000 seF/BBL; hourly superficial velocity of the slurry about 0.3 to 100 □'tf
r-1. Preferably it is about 1 to 1 Q hr-1.

A significant advantage of the process of the invention is that the melting zone 2
and that hydrogen can be supplied to the hydrocracking zone 45 separately. As a result, the hydrogen pressure and II gas supplied to the hydrothermal dissolution zone 20 can be arbitrarily employed, while the simultaneous
Different values can be used for the hydrogen pressure and the amount of gas supplied to the reactor 4. In processes where the hydrogen gas flow and the liquid flow in parallel, this 15-channel flow is not current.Generally, the hydrogen gas flow rate is lower than the water (≦chemical separation zone 20 By installing a pump (not shown) in line 40, it is possible to operate at a lower hydrogen pressure in zone 20 and at a simpler pressure in zone 45. can.

The dissolution zone generally has no external catalyst, but the minerals contained in the coal may have a certain spreading media effect. Not limited to residual light products, bath additives 1
The mixture of molten coal and molten solids is preferably sent via line 30 to a cooling zone 35. cooling zone 35
The melter typically has a heat exchanger or similar means in which the effluent from the melter is cooled below the temperature of the melting process (and at least 425°C (800'B")).
) is cooled to a lower temperature. In zone 35, some decay may also occur due to the addition of fresh cold hydrogen.

One could also choose to remove some solids from zone 35 via line 36.

A mixture of bath agent, l(l# coal, insoluble solids and residual product) is fed through line 40 to reaction zone 45 containing hydrogenated catalyst. Freshly supplied hydrogen and The hydrogen consisting of/or recycled hydrogen is about 4.
00 t) to the hydrocracking zone 45 at the site of b O+OO'J SCF/BBL via line 38. In the hydrocracking reaction zone, hydrogenation and cracking occur simultaneously, compounds with lower molecular weights are converted to lower molecular weight compounds, sulfur in sulfur-rich compounds is converted to hydrogen sulfide, and nitrogen gas conversion @ Nitrogen in substances is converted to ammonia, and oxygen in oxygen compounds is converted to water. Preferably, the catalytic reaction zone is a fixed bed, but it may also be a Foteng or moving bed. Preferably, the mixture of gas, water and insoluble solids passes upwardly through the contact and isolation reaction zones, although downward flow is also possible. It is also optional whether the addition of +10 hydrogen into the liquid occurs countercurrently or cocurrently.

The fundamental advantage of such a mixture of soot liquid and insoluble solids flowing upwardly through a fixed bed of particulate catalyst is that the possibility of blockage is reduced. In downflow operation, the rods in the reactor feed stream can enter the interstices between the fixed catalyst particles. On the other hand, when operating in an upward flow, the particles are subjected to forces in opposite directions, i.e., gravity and the force exerted by the flowing liquid.
Ka.J., I.Tsuteru. These opposing forces act in a direction that can cause bridging phenomena (in addition, gravity acts in a direction that breaks down any local occlusions that may occur).

A particularly desirable way of operating the process is to remove the lower portion of the catalyst. Fresh catalyst can be added to the top of the fixed bed, but it will replace the catalyst removed from the bottom. This addition and removal of catalyst can be carried out periodically, continuously, or semi-continuously. Continuous catalyst exchange according to this method is carried out at such a low rate that the catalyst bed is fixed in nature.

The catalyst used in the hydrocracking zone can be any known, commercially available hydrocracking catalyst. Suitable catalysts used in the hydrocracking reaction step consist of hydrogenation and cracking components.

Preferably, the hydrogenation components are supported on a refractory decomposition carrier. Suitable supports include, for example, silica, alumina, composites of two or more refractory oxides, such as silica-alumina, silica-magnesia, silica-zirconia, alumina-boria, silica-titania, silica-zirconia-titania, acids. Treated clay or similar.

Gold W4 European Phosphorus salts, such as Phosphorus alumina, may also be used. Preferred decomposition carriers are alumina or a composition of silica and alumina. Suitable hydrogenation components are selected from metals of group 6 B of the periodic table, metals of group 8 and their oxides or mixtures thereof.

Sometimes silica-alumina or cobalt on alumina
Molybdenum, nickel-moridine, or nickel-tungsten is used as a carrier. Hydrocracking zone 45 consists of one or more hydrocracking reactors enriched with one or more of the aforementioned catalysts, but not in any combination.

The temperature in the hydrocracking zone is below 425°C (800°F), preferably 34°C, to prevent catalyst deterioration.
5'C to 425'O (645'F' to 800F
], more preferably 340'0 to 400°C (645°C
The temperature of the hydrocracking zone should be about 55°C or about 85°C lower than the melting zone temperature. The conditions include a pressure of 500 to 5,000 psig, preferably 1,000 to 3,000 psig, more preferably 1,500 to 2,500 psig,
The hydrogen gas flow rate is 2,000 to 20,000 Nft/barrel of slurry (SCF/BBL), preferably 3,000 to 10,000 Nft" (SCF/BBL).
/BBL), the hourly superficial velocity of the slurry is 0.
1 to 2.01, preferably 0.2 to 0.5.

The product effluent 50 from reaction zone 45 is separated in separation zone 55 into a gas fall fraction 60, which has a boiling point of about 150° C. or about 260'0 (600° F.
lower than 200°C (400'F), preferably 200°C (400'F)
Lower light crude oils and components that are gaseous in the +'$ state, such as hydrogen, carbon dioxide, carbon dioxide, hydrogen sulfide, and C1 to 04 hydrocarbons. Preferably, the hydrogen is separated from the gaseous components of the pond and recycled. The liquid-solid fraction 65 is conducted to solids separation zone γ0 where it is separated into a solids-lean stream and a solids-rich stream. Non-bathable solids can be removed using conventional methods such as hydroclone, filtration,
Separation is performed by centrifugation, gravity settling, or a combination thereof. Preferably, the non-bathable solids are separated by gravity settling, which is an added advantage. This is because the effluent from the hydrocracking reaction zone has a particularly low viscosity (with an API gravity of at least −6 and i
'Because it's expensive. APi Hiton, which has a high outflow rate, has a solid content of 50t44% due to gravity sedimentation at the end of the book, and the solid content is 50t44%, generally 90%.
K can be rapidly separated by 14 ton force sinking ujj. The non-bathable solid content ranges from 100°G to 400°C (20
Preferably, it is removed by force precipitation at an elevated temperature in the range of 0 to 800 F'. It is particularly desirable to separate solids by increasing temperature and pressure.

The predominantly solids product stream in zone 70, or any fraction thereof, may be recycled to provide additional bath agent to mixing zone 10.

The process of the invention produces a pastry product in standard conditions with a particularly low number of defects. Generating a courageous state in a bad state'1
DA is the entire fraction of products with boiling points lower than C4, they have very low NE, sulfur content lower than 0.2% and 0.5% leading to lower nitrogen poverty rates.

[Brief explanation of drawings]

The Figure is a block flow diagram illustrating suitable flows used to implement one aspect of the present invention. 10・・・・・・Mixed band, 20・・・・・・・・・
・Hydrothermal dissolution-sdripping zone, 3 deaths...
・・Cooling zone, 45... ・−・−Hydrocracking zone,
55... Separation band, 70...
...Solid separation zone. Agent Hiroshi Asamura's drawing of 11゛1 book (no change in content) Stone! -7sy --- Continued from page 1 0 Inventors Dennis Earl, K.A.
19 Force Novato, California, United States Medulane procedural amendment (method) % formula % 1, case display Showa! Patent Application No. 232, 1987, No. 2, Title of Invention 2 β - 71, Relationship between Z and Shi L and Ishiu J Mi 3, Person Making Amendment Case Patent Applicant 4, Agent 1988 〕Mon〉〉6〉6, Number of inventions increased by 8 due to amendment, contents of amendment OL + 1 of drawings as attached (no change in contents)

Claims (1)

[Claims] Mixing fil fat granular coal and a solvent to form a coal-solvent slurry, (bl hydrothermal melting), fully dissolving the coal in the solvent in an IJ lapping zone, and dissolving the coal in the solvent, Iu is removed from the mixture by forming a mixture of molten coal, undissolved solids, and light products while simultaneously contacting the mixture countercurrently with a first hydrogen gas stream at an elevated temperature. a gaseous stream consisting of the light products is withdrawn from the dissolution-stripping zone; A portion is contacted with a second hydrogen gas stream and an externally supplied hydrocracking catalyst at hydrocracking conditions 1, and an effluent stream having a portion of (2) A method of liquefying coal comprising: (2) Claim (1) wherein said melt-stripping zone comprises at least one melt-stripping oak having an internal t%l which substantially reduces backmixing. (3) The method according to claim (1), wherein the temperature in the gas-stripping zone is lowered stepwise such that the temperature at the outlet of the zone is lower than at the inlet of the zone. (4) ) The method according to claim (3), wherein the stepwise decreasing temperature is obtained by using a large number of IJ twisting tanks connected in series. (5) The slurry is Using the first hydrogen gas stream that is preheated and cooler than the slurry, a stepwise decreasing temperature is obtained in one vessel, and the vessel has an internal mechanism that at least partially stops back-mixing. (6) The method of claim (1), wherein the first hydrogen gas stream has a lower flow rate than the second hydrogen gas stream. 7) The hydrothermal dissolution zone) The method according to claim m, in which the hydrogen partial pressure in the IJ Zubing zone is lower than the hydrogen partial pressure in the scale decomposition reaction zone. (8) The dissolution-stripping zone. does not contain an externally supplied catalyst or contact particles (1)
1 is the method listed in S. (9) A method as claimed in claim (1) in which the residence time of the slurry in the hydrothermal melting zone (IJ) is adjusted by using level control in the tank of the melting zone. . a(υ middle distillate is the mixture)
A method according to claim 1, wherein the gaseous stream withdrawn comprises a middle distillate. (Ill. The method according to claim 10, wherein at least a portion of the middle distillate is recycled as a solvent. The method according to claim (1), wherein the mixture is sent to the reaction zone to provide a solid separation step on the way. (A portion of the mixture consisting of the undissolved solids is dissolved) Recirculated to the IJ Zubing zone (15) The method of claim (1), wherein the solvent is crude oil. fl(it) The method of claim (1) is used. Claim (method according to claim 11) consisting of a fraction of crude oil. 07) The method according to claim (1), wherein the solvent consists of a residual fraction of petroleum. (Old) The solvent has a boiling point of 200°C. A process according to claim 1, comprising a higher asphaltized crude oil fraction. C9 A process according to claim 1, wherein the solvent comprises a petroleum derived solvent containing metal impurities. (4 ) The process of claim 1, wherein the temperature of the reaction zone is from about 55° C. to about 85° C. below the temperature of the dissolving-stripping step. Approximately 40
08C to about 480°C
The method described in il.