Method for converting coal to upgraded liquid product

An H-Coal Process hydrogenation operation and catalyst life is substantially improved when using colloidal particles of catalyst comprising a colloidal matrix of silica, alumina, titania and combinations thereof coated with hydrogenating components selected from cobalt, molybdenum, nickel, tungsten and combinations thereof. The colloidal catalyst activity may be altered by alkaline promoters, other metals and acidic promoters.

BACKGROUND OF THE INVENTION 
Coal is considered to be a dirty fuel due in part to its ash and sulfur 
content. Therefore, considerable effort has been expended to develop clean 
fuels from coal in the form of gaseous products, liquid products and solid 
products. The production of relatively clean liquid fuels may be obtained 
by first producing clean syn gas comprising hydrogen and carbon monoxide 
thereafter converted by Fischer-Tropsch synthesis to liquid products. On 
the other hand, the coal may be heated sufficiently to produce naturally 
occurring oils and the thus obtained oils then treated with hydrogen for 
desulfurization and quality improvement. However, such a pyrolysis process 
produces considerable gas and a char product requiring disposal. 
Another route for achieving clean fuels from coal involves dissolving coal 
in a solvent, filtering and catalytically treating the liquid product with 
hydrogen to remove sulfur and improve the quality of the liquid product 
and recycling the hydrotreated product as a preferred solvent. There are 
two primary techniques associated with catalytic hydroliquefaction solvent 
treating coal known as the Synthoil Process and the H-Coal.TM. Process. 
The Synthoil Process slurries crushed and dried coal particles in a portion 
of its own liquefaction product oil. The slurry is fed to and passed 
downwardly through a fixed bed of catalytic material in a reactor and 
contacted therein with turbulently flowing hydrogen. The purpose of this 
treatment is to liquefy and desulfurize the coal liquid product. A 
commercially available hydrogenation catalyst comprising cobalt-molybdate 
on silica activated alumina is a typical catalyst. The product of this 
operation passes through a high pressure receiver where a gaseous product 
is separated. The product slurry oil is passed to a low pressure receiver 
before being centrifuged to remove ash and organic coal residues. Part of 
the centrifuged oil is recycled for use as slurry oil. 
In the H-Coal process, coal is pulverized, dried and slurried with coal 
derived oil. The slurry thus obtained is mixed with hydrogen, heated and 
fed to a reaction zone comprising an ebullating bed of hydrogenation 
catalyst such as a cobalt-molybdenum desulfurizing catalyst. The coal 
liquid slurry is hydrogenated and converted to liquid and gaseous 
products. The reaction conditions are normally about 454.degree. C. 
(850.degree. F.) at 2700 psig. In this prior art known operation, a 
constant catalyst activity is maintained by adding and withdrawing the 
catalyst continuously. A slurry is unconverted coal and liquid product is 
removed from the reactor and recycled to the bottom of the reactor while a 
slip stream is withdrawn and sent to an atmospheric pressure flash drum. 
Flashed vapors are passed to an atmospheric distillation tower and the 
bottoms products are processed in a vacuum tower to obtain vaccum 
distillate overhead and a vacuum bottoms slurry product. A part of the 
heavy distillate product obtained from the top of the vacuum unit and the 
bottom of the atmospheric distillation operation are recycled as 
liquefaction slurry oil for admixture with dried and pulverized coal 
particles. 
The primary objective of coal liquefaction is to produce a low sulfur and 
low ash fuel. This is achieved by treating coal at an elevated temperature 
and hydrogen pressure under conditions promoting hydrogen transfer. This 
may be carried out either in the presence or in the absence of an added 
catalyst depending on the type of coal being processed and product 
desired. It is generally agreed that the production of liquid fuels from 
coal requires the formation of asphaltenes and hydrogenative conversion of 
the asphaltenes to an oil product. The asphaltenes which are formed as 
intermediates in the liquefaction of coal are operationally defined as 
material soluble in benezene and insoluable in aliphatic hydrocarbons such 
as pentane and hexane. Thus conversion of coal to asphaltenes takes place 
at a temperature of about 399.degree. C. (750.degree. F.) or above in the 
presence of a hydrogen donor material. The conversion of the thus formed 
asphaltenes to oil product on the other hand takes place at a reasonable 
rate in the presence of molecular hydrogen of high pressure with a 
hydrogenation catalyst and at relatively high temperature in the range of 
371.degree. to 482.degree. C. (700.degree. to 900.degree. F.). 
It has been observed by early workers in the field that bituminous coal can 
be solubilized at elevated temperatures by aromatic hydrocarbons 
comprising an angular arrangement of rings such as phenanthrene. It is 
poorly achieved with aromatic hydrocarbons with a linear arrangement of 
rings such as provided by anthracene. That is, phenanthrene will dissolve 
up to 95 percent of coal components and anthracene only about 24 percent 
thereof. It has been further observed that the solvating power of the 
liquid is improved considerably as its hydrogen content is increased. 
There are a large number of potential catalyst types available for use in a 
coal liquefaction process. Catalysts such as zinc and tin chloride have 
been shown to be successful, but are expensive, require relatively exotic 
materials for containment, and cause contamination and disposal problems 
of materials in the products. Some disposable catalysts resistant to 
poisoning which do not cause problems with metallurgy or products, appear 
much too expensive (high metals usage) and do not appear to take full 
advantage of the metals present. Supported metal oxide catalysts, such as 
is used in the H-Coal system, have been demonstrated to be successful. 
However, these catalysts are highly susceptible to rapid poisoning by 
carbon, pore structure blockage, and to slow irreversible poisoning due to 
contaminant metals and active molybdenum loss. These catalysts are also 
susceptible to attrition and physical damage within the reaction systems. 
Diffusional limitations within the pore structure of these catalysts is 
also a key mechanistic constraint. 
Major problems in coal liquefaction by supported catalyst systems are pore 
blockage by carbon deposition, diffusion and mass transfer limitations of 
the very large asphaltene/preasphaltene molecules within the relatively 
small, accessable pores, and metals poisoning (particularly by iron, 
titanium, and calcium) plus active hydrogenation metals loss. 
Pore blockage is the classic initial problem with supported catalysts. Very 
rapid deposition of metal contaminants and carbon reduce virgin catalyst 
activity by 80 percent and substantially as soon as the catalyst is 
subjected to the liquefaction environment. This problem is ameliorated by 
either increasing the size (and/or number) of the pores, or by reducing 
particle size of the catalyst to make more surface area accessible near 
the particle surface. An excellent example of this is shown in FIG. I, 
where external surface area is plotted versus particle diameter. 
Diffusional limitation of large molecules within the catalyst particle is 
improved by reducing the particle size of the catalyst, increasing the 
size of the catalyst, increasing the size of the pores, and/or increasing 
the number of feeder pores. However, for the larger asphaltene and/or 
preasphaltene molecules, such as shown in FIG. II, it is difficult to 
conceive of a mechanism by which an active (internal) site could be 
accessed. Thus, because of the limitations of this setup, it is critical 
to improved catalytic liquefaction conversion performance as these large 
molecules are specifically the type of molecules which must be converted. 
Metals poisoning and active metals loss can be bypassed to some extent by 
use of a disposable catalyst system. Metals poisoning of this type has 
been found to be relatively slow, and thus is not considered a major 
factor in the liquefaction processed needed to be overcome.

SUMMARY OF THE INVENTION 
It is believed that many, if not all, of coal liquefaction problems can be 
minimized by reducing the particle size of the hydrogenation catalyst to 
colloidal size catalyst particles. It is thus necessary to effect 
preparation and utilization of colloidal particles, 50 to 200 Angstroms in 
diameter, comprising a matrix material such as that provided by colloidal 
silica, alumina, and/or alumina-coated silica, which matrix is impregnated 
and/or coated with active metal oxides such as cobalt molybdate or nickel 
molybdate or nickel tungsten. Preparation of catalyst particles of a 
colloidal size will substantially increase the exterior accessible active 
particle surface area by a factor considered at least in the same range as 
the inaccessible internal surface area in a more convential extrudate 
hydrogenation catalyst system or composition. 
This large increase in external surface area of the colloidal catalyst will 
substantially reduce diffusional limitations and provide a substrate by 
which active sulfided metal oxides of the hydrotreating catalyst are 
accessible to essentially all large multi-ring molecules directly and in 
the absence of substantial pore blockage or hydrogen donor intermediaries. 
Thus the large multi-ring molecule shown in FIG. II will have greater 
direct catalytic access to the large active external surface area of the 
colloidal particles. 
The use of a disposable colloidal particle in the 50-200 Angstrom-size 
range is considered beneficial during the liquefaction operations. That 
is, a substantial concentration of these colloidal particles, when using 
particularly process derived liquid product or hydroclone material can be 
expected to be retained in the recycled hydroclone material overflow. 
Applicant's approach is to provide a catalyst composition and system 
designed to eliminate intermediary or transfer agent reactions by 
providing direct accessibility of a very extensive catalytic surface area 
to the large molecules comprising preasphaltenes and asphaltene-type 
material which by their size and rapid rate at which internal pores are 
plugged, are normally not able to receive direct hydrogenation. For 
example, with a 1/16" catalyst extrudate, only a very small "portal" 
surface (much less than 1 m.sup.2 /gm) is available for direct 
hydrogenation as against a colloidal catalyst with surface area 
accessibility of 10.sup.2 to 10.sup.3 m.sup.2 /gm (100-10000 m.sup.2 /gm) 
directly as shown by FIG. I. 
It is applicant's position that this problem of inaccessibility is 
substantially effectively addressed by use of a colloidal size, supported 
metal disposable catalyst system. The use of a colloidal system is 
intended to substantially reduce or eliminate diffusional limitations by 
providing substantial, if not all, active catalytic sites as external 
active surface area sites. Carbon and/or contaminant metals poisoning is 
minimized by catalyst disposal; catalytic efficiency is maximized by use 
of a silica, alumina, or a silica-alumina matrix support; and selectively 
for desired hydrogenation and heteroatom removal reactions is tailored by 
the use of a proper type and combination of hydrogenation catalytic metal 
oxides as herein provided. 
The catalyst composition (system) of this invention requires the addition 
of appropriate metal oxides on a colloid support material comprising in 
one embodiment an alumina-coated silica colloid; a silica or an alumina 
colloid alone. By the use of select colloid particles of a particle size 
below 200 Angstroms and preferably below 100 Angstroms comprising the 
hydrogenation metal oxides on the surface of the colloid will be more 
favorably disposed for hydrogenating large molecules. The metal oxides 
(sulfides) thus deposited as colloids will exhibit a much higher surface 
area and thus will have a much higher activity than experienced with the 
larger more conventional extrudate catalyst particles of 1/32 inch size 
and larger of limited diffusion activity. Because of this much higher 
available catalytic surface area provided by the high activity colloidal 
catalytic material, the amount of oxide catalyst deposited per unit weight 
of support (matrix) may be less in some applications than that present on 
available more conventional larger particle hydrogenation coal 
liquefaction catalysts by as much as 15 wt% or more. Thus, the coal 
liquefaction catalyst of this invention utilizes a colloid system of 
silica, alumina, or alumina coated silica particles of 50 Angstroms of 
smaller or larger particle size that have been impregnated with the 
appropriate metal oxides, e.g., cobalt-molybdate; nickel-molybdate; or 
nickel-tungstate, possessing catalytic activity for hydrogenation, 
hydrocracking, hydrodenitrogenation, desulfurization, and deoxygenation 
activities. 
The colloidal catalyst complex (system) of the invention may be utilized 
for upgrading poor quality liquids and/or heavy oils produced from tar 
sands, bitumen, crude oils and shale oil. In the case of shale oil, it may 
be used particularly for catalytically reducing the arsenic content of 
shale oil prior to or during hydrotreating thereof. The use of a colloidal 
catalyst system to reduce the arsenic content of shale oil can also be 
used to greatly extend the cycle life and activity of a more expensive 
hydrotreating catalyst comprising platinum group metals by admixture 
therewith or in a pretreating step before a more conventional 
hydrogenation/hydrocracking process. 
By using a colloidal hydrogenation catalyst complex (system) as herein 
provided, a once-through or recycle operation for coal liquefaction is 
contemplated for enhancing the useful life of the catalyst system 
employed. Conversion by hydrogenation during coal liquefaction is 
associated with the parameters of liquid production, % desulfurization, % 
denitrogenation, % deoxygenation, aromatic saturation and molecular weight 
reduction. 
The catalyst compositions of this invention comprising colloidal size 
material dispersed in a liquid medium is based upon the concept of 
impregnation or dispersion of one or more metal oxides of cobalt, nickel, 
molybdenum or tungsten on an alumina and/or silica colloid or other 
suitable colloid material. Silica and/or alumina and/or titania colloids 
can be a part of the catalyst composition. The activity of these catalyst 
compositions (systems) can be enhanced through the use of one or more 
promoters. These promoters include alkaline materials, other metals below 
identified, and acid materials identified below. 
1. Alkaline Promoter 
(a) Group II metals such as Ba, Sr, Ca 
(b) Rare earths 
(c) Group I metals such as Cs, Rb 
2. Other Metals 
(a) Mu, Bi 
(b) Pb, Sn 
(c) Th, In 
(d) Cr, V 
3. Acidic Promoters 
(a) Halogens 
(b) Phosphate, boria 
(c) TiO.sub.2, ZrO.sub.2 
4. Concentration of promoter would be about 0.01-1 wt.%. 
The present invention is particularly concerned with that portion of an 
H-Coal Process Liquefaction relied upon to produce desired coal oil 
products involving the step of catalytic conversion with hydrogen of 
preasphaltene and asphaltene containing materials to produce quality 
liquid oil products and effect desulfurization and denitrogenation 
thereof. In one particular aspect, the present invention is concerned with 
maintaining the activity of a hydrogenation catalyst employed in a high 
order of activity whereby withdrawal and replacement of catalyst particles 
with fresh catalyst can be reduced by substantial orders of magnitude. In 
yet another more specific respect, the present invention involves the 
employment of a colloidal particle hydrogenation catalyst of desired 
composition dispersed in a liquid medium miscible with the liquid phase 
of, for example, the H-Coal Process coal oil whereby the hydrogenating 
catalyst particles employed are at an elevated temperature and pressure 
selected as herein provided. An ebullating bed of catalyst particles may 
be retained in the reaction zone with colloidal catalyst particles added 
continuously or intermittently over an extended time of operation and/or 
withdrawn and replaced with fresh particles of catalyst of a much lower 
rate. The present invention also involves the employment of a colloidal 
hydrogenation catalyst alone whereby the ebullating bed of catalyst 
particles is not utilized in association therewith. 
A particular objective of the present invention is to prepare colloidal 
particles of silicon oxide, alumina or a combination thereof, with the 
silica colloid coated with one or more layers of alumina and then further 
coating such colloid with hydrogenation components such as 
cobalt-molybdena, nickel-molybdenia, and nickel-tungstate in a desired 
amount. The colloidal particles thus prepared of a size in the range of 20 
to 225 Angstroms, preferably 25-75 Angstroms in diameter, are dispersed in 
a liquid medium which is miscible with the oil phase encountered in the 
coal liquefaction process herein discussed. Thus, the colloidal particles 
are dispersed in a material such as an organic hydrocarbon medium such as 
tetralin, benzene, naphthalene, phenanthrene and anthracene or other 
suitable miscible hydrocarbon solvent material, for ease of introduction 
into the solubilizing oil phase. 
An important aspect of the inventive contribution of the present invention 
is concerned with the method and technique for preparing the colloidal 
particles above identified and providing dispersion thereof in a suitable 
liquid dispersant for use as herein provided. 
In yet another aspect, the colloidal catalyst particles of this invention 
are of a composition comprising two or more hydrogenating compounds of 
from 1-8 wt% nickel oxide, 2-8 wt% cobalt oxide, 3-20 wt% molybdenum oxide 
and 5-20 wt% tungsten oxide. On the other hand, the catalyst particles may 
comprise from 1 to 4 wt% of nickel oxide, from 1-4 wt% cobalt oxide or 
3-12 wt% tungsten oxide. The catalyst particles of colloidal particle size 
and prepared from alumina colloid, silica colloid, and alumina coated 
silica colloid to form colloidal hydrogenation catalyst particles are of a 
size in the range of 20 to 225 Angstroms or of a size in the range of 25 
to 75 Angstroms. The colloidal catalyst particles are employed in the 
hydrogenative conversion of coal oil at a concentration in the range of 5 
to 10,000 ppm and more usually at least 100 ppm with or without the 
presence of larger size hydrogenation catalyst particles as employed in an 
ebullating catalyst bed system. The colloidal catalyst particles are 
recycled with hydroclone to the liquid phase hydrogenation zone of an 
H-Coal Process by one or both of a heavy distillate product of coal oil 
hydrogenation and/or with a separated slurry bottoms product of coal 
liquefaction to which freshly ground coal is added for liquefaction 
hydrogenation conversion thereof. 
The hydrogenation operation of the invention may be accomplished at a 
temperature in the range of 399.degree. to 454.degree. C. or 482.degree. 
C. (750.degree. to 850.degree. F. or 900.degree. F.) at a pressure in the 
range of 2,000 to 4,000 psig and a molecular hydrogen addition rate in 
addition to recycled hydrogen donor materials in the range of 500 to 3,000 
standard cubic feet of hydrogen per barrel of coal slurry oil. 
It will be recognized by those skilled in the art that some minor 
departures may be made to the conditions herein recited with respect to a 
H-Coal Process liquefaction and hydrogenation operation and in the 
colloidal catalyst compositions identified without departing from the 
essence of the invention described and such departures will be considered 
an invasion of the inventive concepts herein expressed. 
The special colloidal composition particularly desired in accordance with 
this invention is found difficult to produce in the absence of a carefully 
controlled sequence of preparation steps. In one preparation sequence, a 
fine particle (colloidal) suspension of aqueous silica-alumina (SiO.sub.2 
/Al.sub.2 O.sub.3) colloid coated with cobalt-molybdena mixtures was 
prepared in an aqueous medium and then dispersed first in ethyl cellusolve 
(ethylene glycol monoethyl ether) by replacing the water by successive 
vacuum flash evaporations. The cellusolve was then replaced with tetralin 
(1,2,3,4-tetrahydronaphthalene) using flash evaporation. This sequence of 
steps produced a very deep blue colored suspension of Co/Mo on alumina 
with a silica core of colloidal particle size comprising approximately 15 
percent or less solids in the suspension depending on the loss of 
particles encountered in the preparation. 
The colloidal suspension desired for use in the process and method of this 
invention may be prepared in the following manner. 
EXAMPLE 1 
A commercially available material identified as a deionized pure SiO.sub.2 
acidic sol of about 3.2 pH is used as a starting material. This material 
is readily miscible with water miscible organic solvents such as ethyl 
cellusolve and is a starting material for the preparation of alumina 
coated silica sols and organic solvent dispersed colloidal silica. In this 
preparation, 16 grams of CoO.sub.3 powder is added slowly (at least 5 
minutes) to a hot agitated solution/suspension of moly-acidic solution and 
heated to a temperature in the range of 80.degree.-85.degree. C. for about 
1/2 hour. At this point of the preparation, the real problem is to bring 
the solution/suspension of Co(H.sub.2 O).sub.6 ++ cations and complex 
anionic isopolymolybdic anions in contact with a positively charged 
colloidally dispersed alumina coated silica sol without causing an 
irreversible coagulation of the colloid. This is accomplished by the 
method of this invention by diluting about 170 ml of the alumina coated 
silica sol suspension with 530 ml of cellusolve and very slowly adding 
this material drop by drop to 1200 ml of the cobalt-moly 
solution/suspension formed above. This is accomplished at a temperature, 
80.degree.-85.degree. C., using maximum available ultrasonic agitation 
over an extended period of time of at least 3 hours. A violet or purple 
stable suspension of particles is obtained. The suspended particles 
appeared to be relatively free of occluded water. A substantial amount of 
the liquid volume is lost by evaporation and is brought up to 1300 ml by 
adding ethyl cellusolve comprising colloidal silica coated with alumina. 
During this addition, the color of the suspension gradually changed from 
pink to violet or purple. Five hundred ml of the above material is placed 
in a flash evaporation zone. The preparation at this point in the 
procedure is not miscible in tetralin. Two flash evaporations of the 500 
ml solution/suspension were carried out, removing about 200 ml of 
cellusolve after the first and second flash evaporations. The cellusolve 
is then replaced with tetralin by replacing the volumes of liquid 
distilled over in the evaporator by tetralin. Cellusolve has a boiling 
point of 136.degree. C. at 1 atmospheric pressure and tetralin boils at 
207.degree. C. A product of this evaporation sequence comprising tetralin 
as the liquid phase in an amount of about 300 ml is observed to be deep 
blue in color. The percent of suspended solids was determined to be about 
15 percent. A portion of this product identified as ACT-31 was mixed with 
a 1/1 by volume mixture of cellusolve and tetralin and flash evaporated. A 
purple muddy precipitate immiscible with tetralin separated out from the 
tetralin supernatant. This purple precipitate was redispersed in 
cellusolve and flash evaporated several times to remove water present and 
to form a stable dispersion of the particles in tetralin. This redispersed 
stable suspension was designated ACT-31A. Some of the precipitate obtained 
as above identified was redispersed in tetralin using the ultrasonator and 
heat. This sample was designated ACT-31B. Another portion of the 
precipitate was heated to dryness above 200.degree. C. The dried particle 
precipitate assumed a dark blue coloration and was then redispersed in 
tetralin. This sample was labeled ACT-33. 
Following several other preparation sequences, it was observed that the 
following preparation technique was the method of choice. 
EXAMPLE II 
In this preparation, to one liter of deionized water at 
80.degree.-85.degree. C. or about 180.degree. F. is added slowly 20 grams 
of MoO.sub.3 and then in a similar manner there is added 16 grams of 
powdered C.sub.0 CO.sub.3 cobalt carbonates. The mixture is stirred and 
heated for approximately one-half hour. With an ultrasonator at maximum 
setting (65) and partially immersed in the Co/Mo solution there is added 
slowly and at a controlled rate a mixture of 70 ml of colloidal silica 
coated with alumina and 430 ml of ethyl cellusolve. It is preferred that 
the temperature be maintained about 180.degree. F. during this mixing and 
addition period. A volume of product of about 1000 ml is obtained after 
substantial water evaporation. The 1000 ml of product is flash evaporated 
until about 400 ml of water and cellusolve have been evaporated. This 
evaporated liquid portion is replaced with pure cellusolve. After 
effecting a sequence of flash evaporations providing particles deep blue 
in color, the temperature is gradually raised during evaporations and the 
displaced cellusolve is replaced with tetralin. A final product of 500 ml 
liquid volume comprising a solids content of about 8.6 wt. percent is 
obtained. This method of preparation may be implemented by employing a 
commercially available colloid of silica coated with alumina and prepared 
by the technique of U.S. Pat. No. 3,252,517. 
The method and concepts of this invention are directed to the development 
of supported and disposable catalyst systems suitable for use in the 
H-Coal Process, H-Oil Process, Synthoil and/or a hydrogen-donor process 
such as the HDDC process and which may be relied upon to maintain and/or 
improve the selectivity of catalyst systems used in a coal liquefaction 
system to form desulfurized oil products from asphaltenes. It is said that 
the liquefaction of coal to form clean liquid oil products goes through a 
sequence of preasphaltene formation with such material thereafter being 
converted to oil product or to asphaltenes and then to oil products by 
catalytic hydrogenation at relatively high temperatures in the range of 
371.degree. C. (700.degree. F.) to 482.degree. C. (900.degree. F.) and a 
pressure within the range of 1500 to 3500 psig. A primary object of the 
present invention is to maximize total distillate oil yield from coal 
liquefaction with improving product quality a secondary objective. On the 
other hand, maximization of the total distillate oil product depends in 
substantial measure upon maintaining the catalyst hydrogenating activity 
as well as its on stream life. The present invention is concerned with 
achieving these objections. 
The use of supported hydrogenating catalyst systems to achieve conversion 
of asphaltenes to desulfurized quality oil products has received the 
greatest amount of attention. However, these catalyst employed as an 
ebullating mass of solid particles in a liquid phase reaction zone with 
all their success are highly susceptible to rapid carbon fouling along 
with irreversible metals poisoning. The present invention is particularly 
concerned with prolonging the active life of the supported catalyst 
systems now employed such as in the H-Coal Process as well as the 
selectivity thereof by the selective addition of a colloidal suspension of 
the catalyst ingredients dispersed in a solution miscible with the 
oil/asphaltene phase existing in the hydrogenation reaction zone. The 
preferred colloidal catalyst ingredients are prepared as above provided 
and are suspended in a liquid hydrocarbon phase in an amount suitable for 
addition to a reaction zone such as the H-Coal Process reaction zone 
either with or without previously charged larger size hydrogenation 
catalyst particles material used as an ebullating bed of catalyst 
particles suspended in a high boiling liquid phase. 
Some major problems recited above in coal liquefaction and hydrogenation of 
formed coal oil product by supported catalyst systems are related to pore 
blockage by carbon deposits, diffusion and mass transfer limitations of 
the very large asphaltenes/preasphaltenes molecules within relatively 
small accessible pores along with metals posioning by iron, titanium and 
calcium plus some active hydrogenation metals loss. 
Each of the above identified catalyst problems can be reduced in 
substantial measure by reducing the particle size of the catalyst 
employed. It is proposed in one embodiment to utilize the colloidal 
particles of catalyst above identified alone or in combination with more 
conventional larger size fluid hydrogenation catalyst particles of the 
prior art and of a size suitable for use as an ebullating bed of catalyst 
particles dispersed in a liquid phase. The colloidal catalyst particles of 
this invention as herein provided may be prepared from materials selected 
from colloidal silica, alumina, alumina coated silica, further coated with 
active hydrogenation metals such as cobalt-molybdenum, nickel-tungsten, 
nickel-molybdenum and obtained from CoCO.sub.3 ; NiCO.sub.3 ; 
Co(NO.sub.3).sub.2 ; Ni(NO.sub.3).sub.2 ; CoCl.sub.2 ; NiCl.sub.2 ; 
H.sub.2 MoO.sub.4, ammonium molybdate or tungstate, tungstic acid and 
sodium molybdate. 
An evaluation of some catalyst systems provided some interesting results 
are discussed below. 
EXAMPLE III 
In this evaluation a fine mesh coal is dispersed in a oil liquefaction 
product as discussed herein particularly with respect to the H-Coal 
Process. The catalyst employed in the different runs were as follows. In 
run number 1, the catalyst was a presulfided colloidal material identified 
above as ACT-33 catalyst material. In run number 2, the catalyst was a 
mixture of a typical cobalt-molybdenum dispersed in alumina catalyst 
identified as 1442A and used in the ebullating catalyst system of H-Oil 
processing. This catalyst 1442A is used in combination with the colloidal 
suspension prepared above and identified as ACT-33. A portion of spent 
1442A catalyst obtained from an H-Oil pilot plant was extracted with THF 
(tetrahydrofuran) to remove deactivating materials particularly comprising 
preasphaltenes. 
The catalyst mixture used in run number 2 was presulfided. In run number 3, 
THF extracted 1442A (CoMoAl) was employed without presulfiding. In run 
number 4, the colloidal suspension identified as ACT-33 was used without 
presulfiding the catalyst. 
The catalyst evaluation runs were completed in a microautoclave at a 
temperature of 454.degree. C. (850.degree. F.) and an elevated pressure in 
which the gram weight of catalyst solids per gram of coal varied as 
follows: 
Run 1--0.16 (ACT-33) presulfided 
Run 2--0.2 (1442A) and 0.02 (ACT-33) presulfided 
Run 3--0.2 (1442A) 
Run4--0.16 (ACT-33) 
The results obtained in these catalyst evaluation runs are as follows: 
______________________________________ 
Run Number 1 2 3 4 
______________________________________ 
Time - Minutes 
30.0 
THF Conversion 
84.8 86.8 84.6 83.0 
Yields, DAF wt. % 
Gases 4.7 5.0 6.7 5.0 
Oils (Oil & Gas) 
44.7 67.1 55.0 49.9 
Asphaltenes 30.8 6.5 20.3 22.7 
Preasphaltenes 
4.7 8.1 2.6 5.4 
Methane 1.85 1.31 2.18 1.80 
Ethane 0.81 0.89 0.97 0.91 
Propane 0.37 0.62 0.60 0.34 
Propylene 0.00 0.03 0.00 0.00 
Isobutane 0.00 0.00 0.00 0.00 
N--Butane 0.10 0.14 0.09 0.07 
CO.sub.2 1.56 1.40 1.72 1.84 
CO 0.00 0.00 0.84 0.00 
H.sub.2 S 0.00 0.60 0.23 0.03 
CI-C.sub.4 Gases 
3.12 2.98 3.83 3.12 
Oil Select. 0.526 0.774 0.650 0.601 
______________________________________ 
It will be observed upon consideration of the data of these catalyst 
evaluation runs that at the levels of conversions identified, run number 2 
achieved the greatest reduction in asphaltenes to form oils (oil and gas) 
in substantial measure over that achieved in the other runs. It is 
therefore concluded that the THF extracted 1442A catalyst in combination 
with the colloidal catalyst suspension identified as ACT-33 contributed a 
synergistic relationship not fully understood in achieving the highest 
conversion of asphaltenes to oil and gas products. It is also observed 
that the gas products (C.sub.1 -C.sub.4 gases) of run 2 are less than that 
obtained in the other runs. These data show that the production of 
hydrogen sulfide is higher in run number 2 than the other runs. One may 
conclude from these data that the activity and life of the catalyst 
particles employed in the hydrogenation of coal liquefaction products to 
produce oil is substantially improved by the addition of a colloidal 
suspension of the catalyst components to the reaction system being 
employed. Thus in the reaction system of the H-Coal Process it is proposed 
to add a colloidal suspension of the catalyst ingredients as herein 
identified and normally employed to maintain and/or sustain the activity 
of initially charged catalyst systems over an extended period of operating 
time. 
In yet another aspect, it is concluded that a spent catalyst recovered from 
a coal liquefaction-hydrogenation operation can be restored to a 
relatively high level of activity by extracting preasphaltene and 
asphaltene-type materials from the catalyst particles with solvents 
suitable for the purpose of either separately or in situ and using the 
extracted catalyst particles in admixture with suspended colloidal 
components to achieve a high degree of hydrogenation of coal liquefaction 
product to a desired liquid oil product. 
The selectivity of the colloidal catalyst for oil production was 
considerably improved over thermally obtained product. 
EXAMPLE IV 
Catalyst Activity Test Program 
Approximately 2 g of a colloidal catalyst suspended in an aqueous or 
organic solvent is added per 100 g of a suitable test hydrocarbon and 
processed at 316.degree.-454.degree. C. (600.degree.-850.degree. F.) and 
1,000-2,000 psig under continuous molecular hydrogen addition. Catalyst 
activity is measured as a function of time in minutes versus the change in 
refractive index of the test hydrocarbon. The test hydrocarbon is 
preferably methylnaphthalene and a change in (RI) refractive index as 
measure of hydrogenation activity, is kept below a 50% tetralin 
concentration to ensure that decalin production does not confuse the RI 
change or rate determination. Gas chromatography is also used to determine 
the degree of hydrogenation. 
The methylnaphthalene can be either a diesel reference fuel which contains 
sulfur and nitrogen impurities or a methylnaphthalene concentrate from a 
high endpoint reforming operation such as Panasol or Marasol (these 
require benzo-thiopene and quinoline additions). Sulfur and nitrogen 
removal is measured at the end of a test period to determine heteroatom 
removal rates. Gas analysis permits evaluation of hydrocracking activity. 
The colloidal catalyst composition (system) may also be substantially 
heated and sulfided prior to addition to the reaction system or 
accomplished in situ. 
The catalyst tests above outlined are designed to be very sensitive to 
changes in catalyst activity, as contrasted to coal liquefaction system 
where significant changes are often masked by gross system effects. The 
best catalyst systems selected on the basis of the outlined tests are then 
tested for efficiency in an actual coal liquefaction operation. 
A microautoclave system is generally composed of four nominal 50 cc batch 
tubing bomb reactors immersed in a fluidized sand bath for temperature 
control. Agitation is provided, as are gas supply systems. Coal, solvent 
and catalysts are batch charged to the reactors. Products are 
quantitatively recovered, including gas volume and sample, solids, 
preasphaltenes, and asphaltenes. Oil yields are calculated by difference. 
Test conditions generally vary according to needs, but general conditions 
are listed below: 
Temperature--399.degree. C.-454.degree. C. (750.degree.-850.degree. F.) 
Pressure--500-1000 psig Cold Hydrogen Charge 
Reaction Time--30-40 minutes 
Coal Charge--5 grams 
Solvent Charge--10-15 grams 
Catalyst Charge--0-3 grams 
Having thus generally described the method and concept of this invention 
and discussed specific examples in support thereof, it is to be understood 
that no undue restrictions are to be imposed by reasons thereof except as 
defined by the following claims.