Process and catalysts for hydroconversion of coal or petroleum asphaltene to distillate liquids

A two-stage catalytic hydroconversion process using a large-pore catalyst in the first stage reactor and a small-pore catalyst in the second stage reactor in the two-stage process for hydroconversion of coal or petroleum asphaltene feed materials to produce distillate liquid fuels. The large-pore catalyst is characterized by having pore diameters larger than 1000.ANG. occupying a major portion of the catalyst total pore volume of 0.2 to 1.0 cc/gm, and the small-pore catalyst is characterized by having pore diameters smaller than 1000.ANG. occupying a major portion of the catalyst total pore volume.

BACKGROUND OF INVENTION 
This invention pertains to a catalytic two-stage hydroconversion process 
for coal or petroleum asphaltene feed materials to produce high yields of 
hydrocarbon distillate liquid products. It pertains particularly to such 
process which uses a large-pore catalyst in the first stage reactor and a 
small-pore catalyst in the second stage reactor, and to the catalysts used 
in the process. 
The primary energy sources today or in the near future are coal and 
petroleum. In several regions of the United States, there are abundant 
supplies of various types of coal including bituminous, semibituminous and 
subbituminous, as well as lignite. To meet the ever increasing demand for 
transportation fuels, many methods have been disclosed in the prior art to 
convert coal into liquid fuels. Since the supply of petroleum is becoming 
depleted, the new upgrading technologies today are aimed at the conversion 
of petroleum asphaltene, which is the bottom of the barrel of crude oil, 
very heavy petroleum crudes or heavy hydrocarbon materials originated from 
tar sand or oil shale. 
Coal and petroleum asphaltene are hydrocarbons having large molecular 
weights and very complicated molecular structures. For the production of 
distillate liquid fuels from coal, a step-wise series of reactions are 
envisioned: coal.fwdarw.preasphaltene (benzene-insoluble 
resid).fwdarw.asphaltene (benzene-soluble hexane-insoluble 
resid).fwdarw.distillate. For petroleum asphaltene processing, the 
reaction for producing distillate liquids proceeds likewise as follows: 
asphaltene (benzene-soluble hexane-insoluble).fwdarw.oil 
(hexane-soluble).fwdarw.distillate liquid. 
Because of the ever increasing demand for transportation fuels relative to 
other energy needs, coal or petroleum asphaltene processing to yield a 
high percentage of distillate product is needed. Numerous methods have 
been disclosed in the art for these purposes. For coal processing, a 
single-stage catalytic process using an ebullating bed catalytic reactor 
is disclosed in U.S. Pat. No. 3,519,555; the catalyst is described as a 
hydrogenation catalyst selected from the group consisting of cobalt, 
molybdenum, nickel, iron and tin supported on a base selected from the 
group consisting of alumina, magnesia and silica. A multistage process for 
the production of hydrocarbons from coal employing a series of ebullating 
bed reactors is disclosed in U.S. Pat. No. 3,594,305. This process 
discloses that two or more of a first group of ebullating bed reactors 
effect removal of sulfur and oxygen and effect some hydrogenation, using 
as catalyst a supported sulfided Co-Mo, Ni-W, or Ni-Mo catalyst, with the 
temperature and pressure of reaction within the reactors being increased 
in each subsequent reactor as the product passes downstream, and a final 
group of reactors containing a noble metal catalyst at higher temperatures 
and pressures than in the first reactor series effect removal of nitrogen 
compounds and hydrogenate aromatic compounds. 
The Solvent Refined Coal (SRC) Process, which recycles process hydrocarbon 
solvent to donate hydrogen for coal liquefaction, has high yield of 
unconverted coal plus resid. The Exxon Donor Solvent (EDS) Process is 
described by Ansell et al in the American Chemical Society, Division of 
Fuel Chemistry Preprints, Vol. 25, No. 3, 1980, p. 269. Using a 
hydrogenated recycle solvent, the process is still limited by low 
conversion of coal and resid. With vacuum bottoms material (1000.degree. 
F.+) recycling, the coal liquefaction and conversion to 1000.degree. F.- 
product is raised from 63 to 83 wt % of MAF Illinois No. 6 coal (Monterey 
mine) accompanied by an increase in hydrogen consumption from 4 to 6% wt. 
basis MAF coal. The high mineral-containing bottom fraction requires 
further processing for hydrogen production. 
A two-stage coal liquefaction process called SRC I-LC Fining, is currently 
being developed. The first stage reaction is thermal, using recycle 
solvent from the catalytic second stage reaction to effect coal 
liquefaction. This two-stage process yields high percentage 1000.degree. 
F.+ materials like the single-stage donor solvent processes. However, at 
the same distillate (1000.degree. F.-) production level, the hydrogen 
consumption of this two-stage process is significantly lower than that of 
the EDS Process. The lower hydrogen consumption of this two-stage process 
is attributed to the lower operating temperature of the second stage 
reactor resulting in lower gas production. 
The catalyst employed in coal liquefaction processes includes a variety of 
catalytically active materials on porous supports having large surface 
area. As stated in the background of U.S. Pat. No. 3,635,814 to Rieve et 
al, the desired pore size for a catalyst is about 50 to 250 .ANG. with the 
most frequent pore size being 60 .ANG.. 
The pore structure of petroleum resid hydrodesulfurization catalyst is 
disclosed in a number of patents. U.S. Pat. No. 3,509,044 favors the 
exclusion of asphaltene by maximizing surface area contained in pores 
having diameters of 30-70 .ANG.. U.S. Pat. No. 3,531,398 discloses an 
upper limit on the amount of macropore volume represented by pore 
diameters greater than 100 .ANG.. U.S. Pat. No. 3,563,886 and U.K. Pat. 
No. 1,122,522 disclose regular pore size distribution of 0 to 240 .ANG. 
with 85% of total pore volume in 50-200 .ANG. range, and suggest that 
catalysts containing mostly micropores will be poisoned rapidly and 
asphaltene which penetrates the larger pores subsequently will block 
entrance to the smaller pores. NPA Pat. No. 6,815,284 discloses the 
desirability of intermediate pores (100 to 1000 .ANG.) plus channels 
(&gt;1000 .ANG.) to take up preferentially absorbed large molecules without 
causing blockage, so that the smaller size pores can desulfurize smaller 
molecules. German Pat. No. 1,770,996 specifies 0.3 cc/mg of pore volume 
in diameters larger than 75A and many pores from 1000 to 50,000A, and 
prefers the open structure for collection of coke and metals. 
Commercial catalyst, such as American Cyanamid HDS 1442A, is an effective 
coal liquefaction catalyst or a petroleum asphaltene hydrodesulfurization 
and hydroconversion catalyst for a single-stage process. Such single-stage 
processes are known respectively as H-Coal process and H-Oil process 
developed by Hydrocarbon Research, Inc. This HDS 1442A catalyst is a 
special Co-Mo catalyst characterized by its bimodal pore size 
distribution, with the micropore diameter peaking around 50A and occupying 
about 2/3 of its total pore volume of 0.7 cc/gm, and the macropore 
diameter peaking around 2000 .ANG. and occupying about 1/3 of the total 
pore volume. This catalyst has to serve many fucntions. For example, for 
coal conversion, the catalyst breaks down the large coal molecules to 
preasphaltene, and converts preasphaltene to asphaltene, then to 
distillate liquids and desulfurizes these fractions. 
A number of significant advantages are obtained by use of a bimodal 
catalyst with a suitable surface area of 100 to 250 m.sup.2 /g, as 
disclosed in U.S. Pat. No. 4,294,685. The catalyst support may be formed 
of gamma alumina with small pores. The preferred alumina support disclosed 
in U.S. Pat. No. 3,635,814 is eta alumina. The large pores can be formed 
by known techniques, such as grinding the alumina to a fine powder and 
then binding the particles together to form extrudates. During that 
process, the large pores are generated. This technique for forming large 
pores is described in U.S. Pat. No. 3,530,066. As disclosed in the art, 
other pore growth promoting conditions may be used, such as heating the 
alumina support material in the presence of a gas or a metal compound, 
steaming at elevated temperatures, etc. In another method, the large pores 
may be introduced during preparation of the base material by the use of 
strong mineral or organic acids. Another method involves the addition of a 
boric acid-phosphoric acid solution to the alumina gel. Still another 
method is to introduce a relatively large amount of removable materials 
which may be volatile or decomposable into gases by the application of 
heat. For example, ammonium carbonate, volatile aromatics, etc., have been 
employed as removable materials. 
Significant process advantages are obtained by using a catalyst with 
bimodal pore size distribution for coal conversion or for petroleum 
asphaltene hydrodesulfurization and conversion. For example, such bimodal 
catalysts are more active and/or deactivate slower. However, the bimodal 
catalyst still has problems. For coal conversion, high temperature and 
high hydrogen pressure are needed for achieving high coal conversion, and 
the preasphaltene conversion capability of this catalyst falls rapidly in 
the beginning of operations. Analysis of spent catalyst shows that the 
micropores are filled with carbon deposition within a few days operations, 
but the macropores contain very little carbon deposition. This indicates 
that carbon deposition causes pore mouth plugging, thereby resulting in 
rapid catalyst deactivation, and that catalysts containing micropores 
smaller than about 50A should be avoided. Metal deposition, such as 
titanium, causes a further gradual deactivation of the catalyst. For 
petroleum hydrodesulfurization and asphaltene conversion, carbon 
deposition and nickel and vanadium deposition cause rapid catalyst 
deactivation. 
Furthermore, a single-stage catalytic hydrocarbon conversion process using 
a catalyst with bimodal pore size distribution has a main drawback that 
all the conversions are effected at one reaction temperature, which is the 
high temperature of about 850.degree. F. needed for rapid conversion of 
coal or petroleum asphaltene. This high reaction temperature produces 
undesired high gas yield and high carbon deposition on the catalyst. High 
gas yield results in a less desirable product distribution and high 
hydrogen consumption. High carbon deposition on the catalyst causes rapid 
catalyst deactivation. Thus, there is a need to improve the single-stage 
catalytic process for hydroconversion of coal and petroleum asphaltene. 
SUMMARY OF INVENTION 
It is, therefore, an object of the present invention to provide a new and 
improved, catalytic two-stage hydroconversion process for the production 
of high yields of low-boiling hydrocarbon liquid products from coal or 
petroleum asphaltene feed materials, which process utilizes large pore 
size catalyst in the first stage reactor to effect high coal and 
preasphaltene conversion or high petroleum asphaltene conversion, and 
utilizes a small pore size catalyst in the second stage reactor to effect 
high coal asphaltene conversion or high petroleum oil conversion. 
Another object of this invention is to reduce the yield of solid products 
(unconverted coal, minerals, etc.) resulting from coal conversion to 
materials having very low fuel value, so that gasification of such solid 
carbonaceous products for hydrogen production is not required. Thus, 
coupling of the emergent coal liquefaction technology with gasification 
technology is avoided, which provides a reduction in risk for overall 
project success and improves the operability of a commercial facility. In 
addition, the elimination of the solid product gasification step lowers 
the facility total capital cost. 
Another object of this invention is to provide a two-stage hydroconversion 
process capable of more efficient utilization of hydrogen than for current 
single-stage coal liquefaction or petroleum asphaltene conversion 
processes. 
Still another object is to provide improved inexpensive, large pore, low 
surface area catalysts containing low amounts of active metals. 
A further object of this invention is to provide a two-stage 
hydroconversion process needing a relatively small preheater. 
Various other objects and advantages of this invention will become apparent 
from the accompanying description and disclosure. 
This invention provides a catalytic two-stage process for the hydrogenation 
and hydroconversion of coal and preasphaltene or petroleum asphaltene 
using a large-pore size catalyst in the first stage reactor and a 
small-pore size catalyst in the second stage reactor. The first-stage 
reactor is usually operated at higher reaction temperature than the 
second-stage reactor. The main function of the large-pore catalyst in the 
first stage reactor is to convert coal and coal preasphaltene to coal 
asphaltene, or to convert petroleum asphaltene to oils, which are further 
converted to distillate liquids in the second stage reactor using a 
small-pore size catalyst. The first stage and second stage reactors are 
preferably ebullated bed reactors. 
The coal hydrogenation process using an ebullated catalyst bed reactor is 
described by U.S. Pat. No. 3,519,555. By concurrently flowing streams of 
coal-oil slurry and hydrogen upwardly through a vessel containing a mass 
of solid particles of a catalyst, and expanding the mass of solid 
particles at least 10% over the volume of the stationary mass, the solid 
particles are placed in random motion by the upflowing streams. The 
characteristics of the ebullated mass of solid particles at a prescribed 
degree of volume expansion can be such that a finer, lighter solid such as 
coal particles and coal minerals will pass upwardly through the mass, so 
that the ebullated catalyst particles are retained in the reactor and the 
finer lighter material may pass from the reactor. To attain the desired 
degree of volume expansion of the catalyst particles, a recycle liquid 
stream may be removed above the upper level of ebullation and recycled 
internally to the bottom of the reactor. The ebullated bed reactor is 
especially suitable as the first-stage reactor in that it permits the 
admission of a feed mixture at temperatures much below the reactor outlet 
temperature. The relatively cold feed mixture will be brought quickly to 
the incipient reaction temperature by internally recycling the hot liquid 
from above the upper level of ebullation. 
For coal liquefaction processes, the feedstream preheater has dual 
functions. Besides providing the sensible heat to bring the coal slurry 
feed to near reactor temperature, the preheater provides heat needed for 
effecting the endothermic coal dissolution which starts at about 
550.degree. F. and finishes at about 700.degree. F. The donor solvent 
speeds up coal dissolution, and affects the exothermic coal hydrogenation 
reaction to a certain extent. The presence of a hydrogenation catalyst in 
the reactor promotes the conversion of dissolved coal and preasphaltene 
and generates heat from the conversion to bring the reactants quickly up 
to effective reaction temperature, hence the portion of the reactor which 
serves as a coal dissolver will be small. Since the preheater costs much 
more than the reactor per unit volume, the presence of a catalyst in the 
first-stage ebullated bed reactor permits the installation of a relatively 
small preheater thereby resulting in lower capital cost. 
For coal processing, the large-pore catalyst used in the first stage 
reactor contains macropores having median pore diameters larger than about 
1000 .ANG. occupying a major part of the total pore volume of the catalyst 
of 0.2-1.0 cc/gm and avoiding micropores having diameters smaller than 
about 50A. For processing bituminous coal, the preferred range of pore 
diameters is 2000 to 9000 .ANG.. The large-pore catalysts having a median 
pore diameter of 2350, 4000, or 8400A, total pore volume of 0.7 cc/g, and 
active metal contents of 1.5 wt % of (Mo+Co or Mo+Ni) in a ratio of five 
MoO.sub.3 to one CoO or to one NiO convert more coal than known HDS 1442A 
catalyst, which has macropore diameters peaking at 2000 .ANG. occupying 
only 1/3 of total pore volume and micropore diameters peaking at 50 .ANG. 
occupying 2/3 of total pore volume, a total pore volume of 0.7 cc/g, and 
active metal contents of 15% MoO.sub.3 and 3% CoO. The large-pore 
catalysts of this invention are as resistant to coking as HDS 1442A. 
Coking occurs during hydrogen-donor solvent processing of coal when the 
amount of donor solvent present in the reactor is insufficient to prevent 
the recombination of the free radicals to form coke, which is insoluble in 
pyridine. The catalyst is capable to promote hydrogen transfer from the 
catalyst surface to terminate the free radicals. Larger pore catalysts 
having median pore diameter of 18,500 .ANG., total pore volume of 0.7 
cc/g, and active metal contents of 1.5% Mo+Co, or Mo+Ni converts less coal 
than HDS 1442A, but converts more coal than donor solvent processing. 
However, the hydrogen consumption for this larger pore catalyst is 
significantly lower than for the three other large-pore catalysts. Use of 
the larger pore catalyst might be adequate under certain processing 
conditions for certain preferred product distribution. Since subbituminous 
coal has larger molecular sizes than bituminous coal, for processing 
subbituminous coal the preferred range of pore diameter is larger than the 
2000 to 9000 .ANG. range preferred for processing bituminous coal. 
The molecular sizes of the first-stage reactor effluent (feed to second 
stage) vary with the rank of coal feed or the origin of the petroleum 
asphaltene, the severity of the processing conditions of the first stage 
reactor, and are affected by the pore sizes of the catalyst in the first 
stage. Thus, the preferred pore size range of the second-stage reactor 
catalyst is best defined as relative to the pore sizes of the first-stage 
catalyst. The preferred pore diameter range of the small-pore catalyst 
used in the second stage reactor is 1/5 to 1/20 of the preferred diameter 
range of pores in the first-stage catalyst. The catalyst in the second 
stage reactor preferably has pore diameters of 75-1000 .ANG.. 
For coal processing, the preferred range of pore diameter of the 
first-stage catalyst is 2000 to 20,000 .ANG. and occupying a major portion 
of the total pore volume. For petroleum asphaltene processing, the 
preferred range of pore diameter of the first-stage catalyst is 1000 to 
3000 .ANG. occupying a major portion of the total pore volume. 
The active metals for these catalyst comprise, but are not limited to Co, 
Mo, Ni, W, Sn and mixtures thereof. The remaining material of these 
catalysts is comprised of a refractory support containing one or more of 
the oxides of aluminum, silicon, calcium, magnesium, or titanium or 
compounds thereof. The preferred refractory supports are aluminum oxide, 
silicon oxide, or a mixture of aluminum oxide and silicon oxide.

A coal such as bituminous, subbituminous or lignite is ground and the coal 
particles mixed with appropriate amounts of the two recycle streams: 
hydrocarbon solvent and solids-containing liquid to form a slurry. The 
coal slurry enters a preheater and exits at a temperature between 
500.degree.-650.degree. F. Such heated coal slurry feedstream is mixed 
with recycle hydrogen as well as make-up hydrogen as needed. 
The entire mixture of coal-oil slurry and hydrogen then enters one or more 
first stage ebullated bed catalytic reactors passing upwardly from the 
bottom at a rate and under pressure and at a temperature to accomplish the 
desired hydrogenation. The catalyst is preferably in the form of 
cylinders, beads or like materials approximately in the size range of 1/32 
to 1/4 inch. The size and shape of the catalyst used will depend on the 
particular processing conditions, e.g. the viscosity, density and velocity 
of the liquid in the reactor. A recycle liquid stream, which may be 
internal or external of the reactor, may be removed above the upper level 
of ebullation and recycled to the bottom of the reactor to maintain an 
ebullated catalyst bed. The catalyst in the first stage reactor contains 
large pores with macrophore diameters not smaller than 1000 .ANG. 
occupying a major portion of its total pore volume, and avoids micropores 
having pore diameters smaller than 50A. The preferred range of diameter of 
these macropores is 2000 to 20,000 .ANG.. The catalyst may contain Co-Mo 
or Ni-Mo on an alumina support. The preferred total pore volume of the 
catalyst is 0.2 to 1 cc/g. Preferred operating conditions are in the range 
of 700.degree. to 900.degree. F. temperature and 2000-3000 psig total 
pressure. Coal throughput is at the rate of 5 to 150 pounds per hour per 
cubic foot of reactor space to achieve high hydroconversion to liquids, so 
that the resulting solid products have very little fuel value. The 
petroleum asphaltene feed rate is between 0.1 to 2.0 liquid hourly space 
velocity (LHSV). 
The process stream leaving the first-stage reactor enters one or more 
second stage reactors at a temperature usually lower than the operating 
temperature of the first stage and under slightly lower pressure. The 
catalyst in the second stage reactor contains pores much smaller than 
pores of the first-stage catalyst. The preferred pore diameter range of 
the second-stage catalyst is 1/5 to 1/20 of the preferred range of pore 
diameter of the first-stage catalyst. Preferred second stage reactor 
operating conditions are in the range of 650.degree. to 850.degree. F. 
temperature and 2000-3000 psig total pressure. Feed throughput is at the 
rate to yield increased hydrocarbon liquid product and a solid product 
having very little fuel value. 
The second stage effluent is separated by a series of conventional 
separators, the gases being separated from the liquid fraction by a series 
of high and low pressure flash stages. The mineral, unconverted coal and 
heavy hydrocarbon materials are separated from the liquid product by 
vacuum distillation or other suitable means. A portion of the liquid 
product will be recycled and used to prepare the initial coal slurry feed. 
A portion of the solid-containing products may also be recycled through 
the first stage or the second stage reactors. 
The following examples are offered to further illustrate the present 
invention. 
EXAMPLE 1 
Comparative experiments are conducted employing a laboratory test designed 
to demonstrate the high coal conversion capability of the large pore 
catalyst (first-stage catalyst) of the present invention. 
A series of catalysts are prepared by impregnating four large-pore alumina 
supports with appropriate salt solutions. These supports are in the form 
of 1/16.times.3/16" extrudates, and having median pore diameter varying 
from 2350 to 18,500A and surface area from 7 to 3 m.sup.2 /g. The 
capability of the support to absorb water is determined. Appropriate 
concentrations of salt solutions are prepared from (NH.sub.4).sub.6 
Mo.sub.7 O.sub.24.4H.sub.2 O and Ni(NO.sub.3).sub.2 6H.sub.2 O or 
Co(NO.sub.3).sub.2.6H.sub.2 O for the preparation of catalyst containing 
1.5 wt % of Mo+Ni or Co in a ratio of 5 to 1 MoO.sub.3 to NiO or CoO. A 
content of 0.75 wt % Mo+Ni or Mo+Co is sufficient to give a monolayer 
coverage of the support with an average pore diameter of 2000A and a pore 
volume of 0.7 cc/g. These solutions are mixed at room temperature to 
produce a quantity sufficient for 100% excess of the amount abosrbed by 
100 g of the support. The support is added to the solution immediately and 
the contents are gently swirled for 5 minutes. For example, for a support 
absorbing 0.7 g H.sub.2 O/g, 2.23 g (NH.sub.4).sub.6 Mo.sub.7 
O.sub.24.4H.sub.2 O is dissolved in 70 g water and 1.42 g 
Ni(NO.sub.3).sub.2.6H.sub.2 O or Co(NO.sub.3).sub.2.6H.sub.2 O in 70 g 
water. The two solutions are mixed and 100 g support is added to this 
solution. The excess solution is drained off. The excess solution on the 
catalyst extrudates is removed by spreading them onto a paper towel and 
rolling gently for a few times. The weight increase of the support is 
determined. The contents of (Mo+Ni or Co) in the catalyst is calculated 
from this weight increase. 
The catalyst extrudates are placed in an oven at room temperature; the 
temperature of the oven is raised to 250.degree. F. in about 30 minutes, 
and the catalyst is dried for 2 hours at 250.degree. F. The extrudates are 
gently stirred and rolled around about every 10 minutes during the period 
of the preheating and the first half hour of drying at 250.degree. F. 
Finally the extrudates are calcined at 930.degree. F. for 2 hours. During 
calcination, the catalyst is mixed by transferring it into another dish 
every half hour. 
The catalyst is pulverized and screened to yield a 20- to 40- mesh 
fraction, which is calcined at 900.degree. F. for 2 hours and cooled in a 
desiccator over P.sub.2 O.sub.5. The calcined catalyst is presulfided with 
10% H.sub.2 S in H.sub.2 in H.sub.2 prior to charging to a reactor. A 
factor is calculated for converting the weight to dry catalyst prior to 
presulfiding. Three Co-Mo catalysts and two Ni-Mo catalysts are prepared. 
Pore size distribution of these five catalysts and HDS 1442A are measured 
by mercury porosimetry at 130.degree. contact angle. The pertinent 
characteristics of these catalysts are shown in Table 1 below. 
TABLE 1 
__________________________________________________________________________ 
PORE CHARACTERISTICS OF LARGE-PORE CATALYST 
Total 
&gt;2,000.ANG. 
2,000- 
Median 
Pore Pore 9,000.ANG. 
Surface 
Packing 
Pore Vol., 
Vol., 
Pore Vol., 
Area Density 
Catalyst 
Dia., .ANG. 
cc/g cc/g cc/g m.sup.2 /g 
lbs/cu ft 
__________________________________________________________________________ 
HDS 1442A 
120* 0.69 0.13 0.11 332 -- 
CT 5227 
2,350 
0.69 0.49 0.44 5.5 38.9 
Co--Mo 
CT 4247 
4,000 
0.69 0.61 0.50 6.9 35.4 
Co--Mo 
CT 4247 
4,000 
0.69 0.61 0.50 6.9 35.4 
Ni--Mo 
CT 6227 
8,400 
0.72 0.71 0.34 3.8 38.0 
Co--Mo 
CT 10267 
18,500 
0.71 0.71 0.21 2.9 -- 
Ni--Mo 
__________________________________________________________________________ 
*Average pore diameter calculated from pore volume of 0.69 cc/g and 
surface area of 332 m.sup.2 /g. 
The characteristics of the Co-Mo catalyst and Ni-Mo catalyst prepared from 
the same alumina support are the same. 
Catalyst activity experiments are carried out in a 1-liter autoclave 
reactor unit. A 300-cc hydrogen reservoir is included in the unit to feed 
the hydrogen needed to maintain a constant operating pressure in the 
reactor. A relative hydrogen consumption value of each experiment can be 
calculated from the pressure drop in the reservoir, which is registered by 
a precision gauge. The feedstocks are a mixture of Kentucky coal and a 
recycle hydrocarbon solvent produced from the Solvent Refined Coal (SRC) 
processing of this coal. Analyses of the coal feed and reaction solvent 
used are shown in Tables 2 and 3. 
TABLE 2 
______________________________________ 
ANALYSIS OF KENTUCKY COAL FEED 
______________________________________ 
Sieve Analysis: 
+100 mesh 0.35% 
100-200 mesh 4.74% 
-200 mesh 94.89% 
Proximate Analysis: 
Moisture 1.33% 
Ash 9.24% 
Volatile Matter 34.20% 
Fixed Carbon 55.23% 
Ultimate Analysis: 
Carbon 72.57% 
Hydrogen 5.23% 
Nitrogen 1.54% 
Sulfur 2.81% 
Chlorine 0.29% 
Ash 9.36% 
Oxygen, by difference 
8.20% 
Pyridine-Insoluble 
70.5% 
______________________________________ 
TABLE 3 
______________________________________ 
ANALYSIS OF REACTION SOLVENT 
______________________________________ 
Elemental Analysis 
Carbon 85.98% 
Hydrogen 8.51% 
Nitrogen 0.66% 
Sulfur 0.39% 
Chlorine 0.15% 
Ash 0.11% 
Oxygen, by difference 
4.20% 
ASTM Distillation 
Vol. % off Vapor Temperature, .degree.F. 
IBP 438 
10 484 
20 503 
30 515 
40 531 
50 555 
60 587 
70 621 
80 667 
90 728 
95 781 
96 (end point) 806 
Residue 2% 
Loss 2% 
Experiments are carried out under conditions listed below. 
Coal charge, g 50 
SRC recycle solvent, g 
100 
Catalyst, 20-40 mesh, presulfided, g 
7.5 
Temperature, .degree.F. 
830, 850 
Reaction time, min 30 
Pressure, psig 2500 
Stirring rate, rpm 1000 
______________________________________ 
The reaction product is analyzed as follows. The autoclave contents are 
transferred into a beaker and weighed, then filtered under vacuum on a 
3-in Buchner funnel using Whatman #30 filter paper (medium porosity). The 
autoclave is rinsed 3 times with 15 cc tetrahydrofuran each time, and the 
rinsings are combined and used to wash the filter. Finally the filter cake 
is washed with 50 cc fresh tetrahydrofuran. The filter cake together with 
the funnel is transferred into a beaker and dried at 250.degree. F. to 
constant weight. 
The entire amount of filter cake, consisting of catalyst and coal residue 
together with the filter paper, is transferred to a thimble and extracted 
with 240 cc tetrahydrofuran (THF) in a Soxhlet extractor. The extraction 
is carried out over a period of 17 hours. After extraction, the thimble 
containing filter paper, catalyst, and coal residue is dried at 
250.degree. F. to constant weight. The weight of THF-insoluble residue 
(including catalyst) is calculated by substracting the weight of filter 
paper and thimble from the total weight. The thimble containing the 
tetrahydrofuran-insoluble coal residue, catalyst and filter paper is put 
back in the Soxhlet extractor and extracted with 240 cc pyridine for 17 
hours. After pyridine extraction, the thimble and its contents are dried 
at 280.degree. F. overnight to constant weight. The weight of 
pyridine-insoluble residue (including catalyst) is calculated. The thimble 
and its contents are ashed in a muffle furnace, following ASTM D 3174-73 
procedure, "Ash in the Analysis of Coal and Coke". The extraction residue 
is ashed in a muffle furnace at 1290.degree. to 1380.degree. F. for 4 
hours, cooled and weighed. This is followed by another ashing step at 
1380.degree. F. for 2 hours to assure the completeness of ashing. The loss 
of catalyst weight under this second ashing condition is insignificant. 
The percentages of THF-insoluble and pyridine-insoluble yields of dry coal 
are calculated from the weights of THF-insoluble or pyridine-insoluble 
residue and the weight of ash. 
The filtrates and washings combined with the THF extract are charged to a 
distillation flask and the tetrahydrofuran is distilled off. The 
THF-soluble liquid product is distilled under vacuum, following ASTM D 
1160-77 procedure, to 975.degree. F. (atmospheric pressure). The 
975.degree. F.+ fraction is weighed and ground. Three g of 975.degree. F.+ 
is extracted with 100 cc of toluene in a Soxhlet extractor for 17 hours. 
The residue is dried to constant weight at 250.degree. F. and ashed in a 
muffle furnace. Usually an insignificant amount of ash, if any, is 
obtained. The percentages of 975.degree. F.+ and toluene-insoluble 
975.degree. F.+ materials are calculated. Toluene-soluble of 975.degree. 
F.+ material is obtained by difference. 
Similar catalyst activity experiments are conducted using five large pore 
catalysts. Among these five, three catalysts contain 1.5% (Mo+Co) and two 
contain 1.5% (Mo+Ni). Two types of baseline experiments are carried out: 
(1) thermal reaction without any catalyst, and (2) reaction with a sample 
of HDS 1442A catalyst obtained from Hydrocarbon Research, Inc., which is a 
commercial catalyst used in the H-Coal Process. Experiments are carried 
out at two temperature levels, 830.degree. F. and 850.degree. F. The 
autoclave unit is a static system operated at constant pressure of 2500 
psig. More gas product is produced at 850.degree. F. than at 830.degree. 
F. so the hydrogen partial pressure in the autoclave is higher at 
830.degree. F. than at 850.degree. F. Hence the 850.degree. F. operation 
favors coke formation in comparison to the 830.degree. F. operation. 
Catalyst evaluation at two temperature levels provides information about 
the coking resistant capability of the catalyst. 
Table 4 shows the resulting distribution of 975.degree. F.+ materials: 
unconverted coal plus coke (THF-insoluble or pyridine-insoluble), 
preasphaltene (toluene-insoluble), and the sum of these two. 
A small but consistent difference exists between THF-insoluble and 
pyridine-insoluble materials. 
TABLE 4 
__________________________________________________________________________ 
HEAVY PRODUCT YIELDS (975.degree. F.+) WT % OF COAL FEED 
Unconverted Coal + Coke 
Toluene-Insoluble + 
Preasphaltene 
Tetrahydrofuran 
Pyridine Tetrahydrofuran 
Catalyst (Toluene-Insoluble) 
Insoluble 
Insoluble 
Insoluble 
Designation 
830.degree. F. 
850.degree. F. 
830.degree. F. 
850.degree. F. 
830.degree. F. 
850.degree. F. 
830.degree. F. 
850.degree. F. 
__________________________________________________________________________ 
Thermal 37.4 32.1 12.5 17.1 
11.8 16.6 
49.9 49.2 
HDS 1442A 
28.8 28.2 11.9 12.6 
11.8 12.3 
40.7 40.8 
CT 5227 Co--Mo 
40.8 35.5 5.5 6.8 4.9 6.5 46.3 42.3 
CT 4247 Ni--Mo 
36.2 36.9 7.8 8.1 7.4 7.6 44.0 45.0 
CT 4247 Co--Mo 
38.2, 34.6 
32.0 6.4, 6.9 
8.3 6.3, 6.5 
7.9 44.6, 41.5 
40.3 
CT 6227 Co--Mo 
38.8 34.0 6.7 7.8 6.3 7.2 45.5 41.8 
CT 10267 Ni--Mo 
39.3 36.9 8.7 12.7 
8.6 12.0 
48.0 49.6 
__________________________________________________________________________ 
The pyridine-insoluble yields are about 0.5% lower than the THF-insoluble 
yields. The large pore catalysts produce much higher coal conversion than 
the HDS 1442A catalyst which converts more coal than the thermal 
operation. 
Comparing the data between 830.degree. and the 850.degree. F. reaction 
temperatures, an increase in unconverted coal yield from 12.5% to 17.1% 
for the thermal experiments indicates that more coking occurs at 
850.degree. F. Four large pore catalysts are at least as resistant to 
coking as HDS 1442A catalyst, as shown by their ability to maintain the 
unconverted coal yields under 850.degree. F. reaction temperature at 
substantially the same level as those at 830.degree. F. One large pore 
catalyst, CT 10267 Ni-Mo, which has much larger pores than the other four, 
does not prevent coking at 850.degree. F. 
HDS 1442A catalyst has lower preasphaltene yields than the large pore 
catalysts. The sum of unconverted coal and preaasphaltene yields are the 
highest for the thermal and the larger pore catalyst at 49% of coal feed, 
and lowest for HDS 1442A catalyst at 41% of coal feed. The large pore 
catalysts yield an average of 43.5% unconverted coal and preasphaltene 
which is in the middle of the range. 
The pressure drop in the hydrogen reservoir is recorded during each 
experiment and used as a measure of relative hydrogen consumption. These 
pressure drop data represent a set of relative values between catalytic 
and thermal experiments at a certain temperature. These relative hydrogen 
consumption values fall into 4 groups as shown in Table 5. 
TABLE 5 
______________________________________ 
RELATIVE HYDROGEN CONSUMPTION VALUES 
g H.sub.2 /100 g Coal, calculated from 
Catalyst pressure drop in hydrogen reservoir 
Designation At 830.degree. F. 
At 850.degree. F. 
______________________________________ 
Thermal 0.4 0.05 
HDS 1442A 1.5 1.3-1.7 
Large Pore Catalysts 
0.7-1.5 0.8-1.1 
Larger Pore Catalyst 
0.54 0.57 
______________________________________ 
The relative hydrogen consumption values utilizing the catalysts are in the 
following order: HDS 1442A&gt;large pore catalysts&gt;larger pore 
catalyst&gt;thermal, whereas the unconverted coal+coke yields fall into the 
following order: thermal&gt;HDS 1442A.perspectiveto.larger pore 
catalyst&gt;larger pore catalysts. These data indicate that, using a large 
pore catalyst, hydrogen is selectively consumed towards coal conversion. 
EXAMPLE 2 
These experiments are carried out to demonstrate the excellent quality of 
the large pore catalyst of the invention in achieving a low deactivation 
rate. Catalyst aging tests are conducted employing a continuous coal 
liquefaction unit to establish catalyst aging behavior in an 160-hour 
test. The continuous unit consists of sections for coal slurry feed, 
hydrogen feed, 1-liter stirred autoclave reactor, and liquid product 
collectors. The autoclave reactor contains an annular catalyst basket 
placed in a fixed position and an impeller. The catalyst basket and 
impeller are designed to give adequate mixing and contacting of the 
reaction mixture with the catalyst. 
The standard test conditions are: 
______________________________________ 
Catalyst 60 cc, 1/16" extrudate 
Coal slurry 25% Illinois No. 6 coal in SRC solvent 
Temperature 825.degree. F. 
Pressure 2000 psig 
Reactor holdup 
315 cc 
H.sub.2 feed rate 
225 1/hr (8 SCFH) 
Slurry feed rate 
410 g/hr 
Residence time 
47 min. 
LHSV 1.7 g coal/hr/cc catalyst 
Mixing speed 1500 rpm 
______________________________________ 
Comparative experiments are conducted with catalysts under the standard 
conditions. These experiments are: thermal, HDS 1442A, and CT 4247 Co-Mo 
catalysts. A thermal experiment yields 14% unconverted coal and 29% 
preasphaltene basis MAF coal. Catalyst aging data are shown in Table 6. 
TABLE 6 
__________________________________________________________________________ 
CATALYST AGING DATA 
Time 
Catalyst 
Heavy Product Yields, Wt % of MAF Coal 
on Age Unconverted Coal 
Preasphaltene Unconverted Coal + 
Stream 
lb. Coal per 
(THf-Insoluble) 
(Benzene-Insoluble) 
Preasphaltene 
Hour 
lb. Catalyst 
HDS1442A 
CT4247 Co--Mo 
HDS1442A 
CT4247 Co--Mo 
HDS1442A 
CT4247 Co--Mo 
__________________________________________________________________________ 
21 56 12 8 10 26 22 34 
43 115 12 8 13 27 25 35 
67 179 11 9 17 25 28 34 
90 240 13 9 19 26 32 35 
116 310 13 10 20 28 33 38 
139 371 14 9 20 28 34 37 
163 435 13 10 24 27 37 37 
__________________________________________________________________________ 
CT 4247 Co-Mo shows consistently lower unconverted coal yields than HDS 
1442A catalyst. For preasphaltene conversion, HDS 1442A has high initial 
activity, but its activity decreases rapidly. CT 4247 shows low initial 
activity, but hardly any deactivation. At the end of 163 hours and 
catalyst age of 435 lb. coal/lb. catalyst, HDS 1442A approaches CT 4247 
Co-Mo's performance in preasphaltene conversion. The catalyst deactivation 
data indicate that, having very low catalyst deactivation rate, the 
replacement rate of CT 4247 Co-Mo catalyst should be lower than that of 
HDS 1442A to attain the same level of preasphaltene conversion. 
Analyses of used catalysts show that used CT 4247 Co-Mo contains only 1.9% 
carbon and used HDS 1442A contains 15% carbon. Since CT 4247 Co-Mo and HDS 
1442A have the same pore volume, 0.7 cc/g, CT 4247 Co-Mo will have more 
pore volume available to accommodate metal deposition than will HDS 1442A 
catalyst. 
EXAMPLE 3 
This series of experiments are conducted to demonstrate (1) the excellent 
capability of the small pore catalyst to effect coal asphaltene conversion 
in the second stage reaction, and (2) the high asphaltene conversion 
achieved at reaction temperature lower than that of the first stage 
reactor. 
Experiments are carried out in an up-flow fixed bed reactor. Heat is 
supplied to the reactor by means of an electrically heated lead bath 
designed to maintain isothermal operation. The reactor has an inside 
diameter of 1/2 inch; the catalyst bed is 13 inches long and occupies a 
volume of 150 cc. The feed material mixed with hydrogen is fed to the 
reactor. The mixed vapor and liquid product from the reactor is cooled and 
passed to a high pressure receiver. The liquid is let down in pressure and 
passed to a low pressure receiver. The gas stream is vented, and the 
liquid product is collected and weighed periodically. 
The feedstock is a mixture of 40% SRC product and 60% SRC solvent from SRC 
processing of Illinois No. 6 coal (Monterey. Analyses of the feedstock is 
shown in Table 7. 
TABLE 7 
______________________________________ 
ANALYSES OF SRC FEEDSTOCK 
______________________________________ 
Distillation, volume % at .degree.F. 
IBP 403 
10 516 
30 605 
50 730 
70 1000 
IBP--975.degree. F. 65.4 wt % 
975.degree. F.+ 34.6 wt % 
975.degree. F.+, toulene-insoluble (preasphaltene) 
10.4 wt % 
975.degree. F.+, toulene-soluble (asphaltene) 
24.2 wt % 
975.degree. F.+, benzene-insoluble (preasphaltene) 
8.5 wt % 
975.degree. F.+, benzene-soluble (asphaltene) 
26.1 wt % 
______________________________________ 
The experiments are carried out at 810.degree. and 850.degree. F., 2800 
psig total pressure, and 0.5 LHSV (volume of feed/hour/volume of 
catalyst), and excess hydrogen of 4000 SCF/Bbl. The catalyst is 
presulfided in the reactor prior to operation. At the end of a 3-day 
operation, a liquid product collected during the last 12-hour period is 
distilled to determine the wt % of 975.degree. F.+ fraction. The 
975.degree. F.+ fraction is extracted by benzene or toluene in a Soxhlet 
extractor for its soluble and insoluble contents. Preasphaltene conversion 
and asphaltene conversion are calculated on the basis of these contents of 
the feedstock. 
A standard shutdown procedure is used upon completion of an experiment, 
wherein the temperature is lowered to 650.degree. F., and the catalyst is 
washed with anthracene oil for 1 hour. A representative sample of the used 
catalyst is extracted with benzene to remove any absorbed oil. After 
drying, the carbon content of the used catalyst is determined. 
Comparative experiments are conducted on four catalysts containing Co-Mo or 
Ni-Mo on alumina with different pore characteristics. A description of 
these four catalysts together with their capabilities in conversion of 
975.degree. F.+ materials are summarized in Table 8. Preasphaltene 
conversions are above 95% among all the seven experiments conducted, with 
HDS 1442A having the lowest conversion. The asphaltene conversions are 
affected by reaction temperature, the metal composition and the pore 
characteristics of the catalyst and vary from 22 to 67%. CT 1008 has the 
same pore characteristics as the base catalyst HDS 1442A; CT 1008 contains 
Ni and Mo instead of Co and Mo. At 850.degree. F. reaction temperature, 
the Ni-Mo catalyst shows higher asphaltene conversion than the Co-Mo 
catalyst. In addition, the capability of the Ni-Mo catalyst in asphaltene 
conversion increases with a drop in reaction temperature to 810.degree. 
F., whereas the Co-Mo catalyst shows a decrease in asphaltene conversion. 
This reverse temperature effect shown by the Ni-Mo catalyst may be caused 
by the observed decrease of the carbon content of the used catalyst from 
28.5 to 23.8 wt. % CT 2008 differs from CT 1008 in that it does not 
possess any significant amounts of macropores &gt;1000 .ANG.. Its superior 
ability in asphaltene conversion demonstrate that the presence of 
macropores &gt;1000 .ANG. is not needed for asphaltene conversion. 
TABLE 8 
______________________________________ 
CHARACTERISTICS OF SMALL PORE CATALYSTS AND 
THEIR CAPABILITIES IN CONVERSION 
975.degree. F. + MATERIALS 
Catalyst No. 
HDS 1442A CT 1008 CT 2088 
CT 5008 
______________________________________ 
Mo O.sub.3, % 
16.0 17.2 15.3 10.1 
Co O, % 3.2 -- -- -- 
Ni O, % -- 3.5 3.2 2.4 
Size and Shape 
1/16 inch extrudates 
Surface Area, 
332 267 305 188 
M.sup.2 /g 
Pore Size 
Distribution 
PV cc/g &lt;75.ANG. 
0.37 0.35 0.48 0.11 
75-150.ANG. 
0.06 0.06 0 0.37 
150-1,000.ANG. 
0.17 0.09 0 0.02 
&gt;1,000.ANG. 
0.19 0.22 0.02 0.02 
Total 0.69 0.72 0.50 0.52 
Preasphaltene 
Conversion 
% at 850.degree. F. 
95.2 99.2 -- -- 
% at 810.degree. F. 
95.6 99.7, 99.8 
99.9 99.9 
Asphaltene 
Conversion 
% at 850.degree. F. 
35.6 53.6 -- -- 
% at 810.degree. F. 
22.2 55.9, 58.2 
61.9 67 
Carbon in Used 
Catalyst 
% at 850.degree. F. 
30.1 28.5 -- -- 
% at 810.degree. F. 
25.3 23.3, 24.3 
22.1 19 
______________________________________ 
CT 5008 differs from CT 2008 in that the major portion of &lt;75 .ANG. 
micropores shift to 75 to 150 .ANG. and CT 5008 has lower surface area and 
contains less Mo+Ni than CT 2008. CT 5008 has higher asphaltene conversion 
than CT 2008. This set of comparative experiments demonstrates that pore 
sizes &gt;75 .ANG. are needed for asphaltene conversion. 
While I have shown and described a preferred form of embodiment of my 
invention, I am aware that modifications may be made thereto and I 
therefore desire a broad interpretation of my invention within the scope 
and spirit of the description herein and of the claims appended 
hereinafter.