Hydrovisbreaking process for hydrocarbon containing feed streams

A hydrogen donor solvent selected from the group consisting of a full range crude oil and an atmospheric topped crude oil is used in a hydrovisbreaking process. The heavy fraction being processed is heated in the presence of hydrogen and the solvent under suitable hydrovisbreaking conditions. As a result, the amount of heavies in the feed to the hydrovisbreaking process is substantially reduced.

This invention relates to a hydrovisbreaking process for hydrocarbon 
containing feed streams. In one aspect, this invention relates to a novel 
solvent for a hydrovisbreaking process. 
It is often desirable to reduce the amount of heavies in the heavier 
fractions such as topped crude and residuum obtained during the processing 
of a crude oil. As used herein, the term heavies refers to the fraction 
having a boiling range higher than about 1000.degree. F. This reduction 
results in the production of lighter components which are of higher value 
and which are more easily processed. 
A hydrovisbreaking process is a process which can be used to crack a 
feedstock. Hydrovisbreaking is generally characterized by a heat soak in 
the presence of hydrogen. However, while a heat soak in the presence of 
hydrogen is effective to crack fractions lighter than a topped crude, a 
hydrogen donor solvent must be used when hydrovisbreaking topped crudes or 
residuum to enhance the transfer of hydrogen to the heavies. 
It is thus an object of this invention to provide a novel solvent for a 
hydrovisbreaking process used to process heavier fractions such as topped 
crude and residuum. 
In accordance with the present invention, a hydrogen donor solvent selected 
from the group consisting of a full range crude oil and an atmospheric 
topped crude oil is used in a hydrovisbreaking process. The heavy fraction 
being processed is heated in the presence of hydrogen and the solvent 
under suitable hydrovisbreaking conditions. As a result, the amount of 
heavies in the feed to the hydrovisbreaking process are substantially 
reduced by means of cracking. The solvent of the present invention is 
cheaper than other solvents which might be employed which is of 
considerable importance when processing heavy fractions such as topped 
crude or residuum.

Any suitable hydrocarbon containing feed stream may be processed in 
accordance with the present invention. Such suitable hydrocarbon 
containing feed streams will generally contain a high concentration of 
heavies. The invention is particularly directed to processing heavy topped 
crudes, residuum and other materials which are generally regarded as too 
heavy to be distilled. Again, heavies are defined as those fractions 
having a boiling range higher than about 1000.degree. F. 
Referring now to FIG. 1, a full range crude (undistilled) is supplied 
through conduit 11 to the atmospheric fractionator 12. A bottoms stream, 
which is referred to as atmospheric topped crude, is withdrawn from a 
lower portion of the atmospheric fractionator 12 through conduit 14 and is 
provided as a feed to the vacuum fractionator 15. 
A bottoms stream, which is referred to as vacuum topped crude, is withdrawn 
through conduit 16 from a lower portion of the vacuum fractionator 15. The 
vacuum topped crude is provided as a feed to the solvent extraction column 
18. In the solvent extraction column 18, the vacuum topped crude is mixed 
with a solvent such as propane and a part of the vaccum topped crude will 
be dissolved in the solvent with the solvent phase being removed from an 
upper portion of the solvent extraction column 18. A very heavy material, 
which is referred to as solvent extracted topped crude, is withdrawn from 
a lower portion of the solvent extraction column 18 through conduit 19 and 
is provided to the hydrovisbreaking process 21. 
Hydrogen is provided to the hydrovisbreaking process 21 through conduit 23. 
A portion of the crude oil flowing through conduit 11 to the atmospheric 
fractionator 12 is also provided to the hydrovisbreaking process 21 
through conduit 27. This full range crude oil is utilized as the solvent 
for the hydrovisbreaking process. In addition, a decomposable compound of 
molybenum, which will be described more fully hereinafter, is also 
preferably provided to the hydrovisbreaking process 21. 
In the hydrovisbreaking process 21, which will be described more fully 
hereinafter, the amount of heavies in the solvent extracted topped crude 
is reduced. The reaction effluent from the hydrovisbreaking process 21 is 
recycled through conduit 26 and is provided as a feed to the atmospheric 
fractionator 12. Some part of such reaction effluent may be drawn off if 
desired. 
The operation of the atmospheric fractionator, vacuum fractionator and 
solvent extraction columns are all well known and will not be described 
more fully hereinafter since such operation plays no part in the present 
invention other than to provide the desired feed and the desired solvent. 
It is also noted that a number of other streams would be withdrawn from the 
columns and there would be additional equipment such as pumps, heat 
exchangers, control components, etc. which would typically be associated 
with the columns. Such additional equipment have not been illustrated 
since these additional components play no part in the description of the 
present invention. 
Any suitable amount of the full range crude may be provided through conduit 
27 as a solvent for the hydrovisbreaking process 21. The amount of full 
range crude provided to the hydrovisbreaking process 21 will be in the 
range of about 5 weight percent to about 95 weight percent based on the 
total weight of the solvent extracted topped crude and full range crude 
provided to the hydrovisbreaking process 21. 
The use of the decomposable compound of molybdenum is not required but is 
preferred. Particularly preferred molybdenum compounds are molybdenum 
dithiophosphate and molybdenum dithiocarbamate. 
Any suitable molybdenum dithiophosphate compound may be used in the 
hydrovisbreaking process. Generic formulas of suitable molybdenum 
dithiophosphates are: 
##STR1## 
wherein n=3,4,5,6; R.sup.1 and R.sup.2 are either independently selected 
from H, alkyl groups having 1-20 carbon atoms, cycloalkyl or 
alkylcycloalkyl groups having 3-22 carbon atoms and aryl, alkylaryl or 
cycloalkylaryl groups having 6-25 carbon atoms; or R.sup.1 and R.sup.2 are 
combined in one alkylene group of the structure 
##STR2## 
with R.sup.3 and R.sup.4 being independently selected from H, alkyl, 
cycloalkyl, alkylcycloalkyl and aryl, alkylaryl and cycloalkylaryl groups 
as defined above, and x ranging from 1 to 10. 
##STR3## 
wherein p=0,1,2; q=0,1,2; (p+q)=1,2; 
r=1,2,3,4 for (p+q)=1 and 
r=1,2 for (p+q)=2; 
##STR4## 
wherein t=0,1,2,3,4; u=0,1,2,3,4; 
(t+u)=1,2,3,4 
v=4,6,8,10 for (t+u)=1; v=2,4,6,8 for (t+u)=2; 
v=2,4,6 for (t+u)=3, v=2,4 for (t+u)=4. 
Sulfurized oxomolybdenum (V) O,O'-di(2-ethylhexyl)phosphorodithioate of the 
formula Mo.sub.2 S.sub.2 O.sub.2 [S.sub.2 P(OC.sub.8 H.sub.17).sub.2 ] is 
a particularly preferred additive. 
Any suitable molybdenum dithiocarbamate compound may be used in the 
hydrovisbreaking process. Generic formulas of suitable molybdenum (III), 
(IV), (V) and (VI) dithiocarbamates are: 
##STR5## 
wherein n=3,4,5,6; m=1,2; R.sup.1 and R.sup.2 are either independently 
selected from H, alkyl group having 1-20 carbon atoms, cycloalkyl groups 
having 3-22 carbon atoms and aryl groups having 6-25 carbon atoms; or 
R.sup.1 and R.sup.2 are combined in one alkylene group of the structure 
##STR6## 
with R.sup.3 and R.sup.4 being independently selected from H, alkyl, 
cycloalkyl and aryl groups as defined above, and x ranging from 1 to 10. 
##STR7## 
wherein p=0,1,2; q=0,1,2; (p+q)=1,2; 
r=1,2,3,4 for (p+q)=1 and 
r=1,2 for (p+q)=2; 
##STR8## 
wherein t=0,1,2,3,4; u=0,1,2,3,4; 
(t+u)=1,2,3,4 
v=4,6,8,10 for (t+u)=1; v=2,4,6,8 for (t+u)=2; 
v=2,4,6 for (t+u)=3, v=2,4 for (t+u)=4. 
Molybdenum(V) di(tridecyl)dithiocarbamate is a particularly preferred 
additive. 
Any suitable concentration of the molybdenum additive may be added to the 
solvent extracted topped crude flowing through conduit 19. In general, a 
sufficient quantity of the additive will be added to the solvent extracted 
topped crude flowing through conduit 19 to result in a concentration of 
molybdenum metal in the total feed plus solvent in the range of about 1 to 
about 5000 ppm and more preferably in the range of about 10 to about 1000 
ppm. 
The hyrovisbreaking process 21 can be carried out by means of any suitable 
apparatus whereby there is achieved a contact of the solvent extracted 
topped crude flowing through conduit 19, the decomposable molybdenum 
compound, hydrogen and the full range crude under suitable 
hydrovisbreaking conditions. The hydrovisbreaking process can be carried 
out as a continuous process or as a batch process. The hydrovisbreaking 
process is in no way limited to the use of any particular type of process 
or apparatus. 
The molybdenum compound may be combined with the feed stream in any 
suitable manner. The molybdenum compound may be mixed with the feed stream 
as a solid or liquid or may be dissolved in a suitable solvent (preferably 
an oil) prior to introduction into the feed stream. Any suitable mixing 
time may be used. However, it is believed that simply injecting the 
molybdenum compound into the feed stream is sufficient. No special mixing 
equipment or mixing period are required. 
The pressure and temperature at which the molybdenum compound is introduced 
into the feed stream is not thought to be critical. However, a temperature 
above 100.degree. C. is recommended. 
Any suitable reaction time in the hydrovisbreaking process may be utilized. 
In general, the reaction time will range from about 0.01 hours to about 10 
hours. Preferably, the reaction time will range from about 0.1 to about 5 
hours and more preferably from about 0.25 to about 3 hours. Thus, for a 
continuous process, the flow rate of the feed should be such that the time 
required for the passage of the mixture through the reactor (residence 
time) will preferably be in the range of about 0.1 to about 5 hours and 
more preferably about 0.25 to about 3 hours. For a batch process, the feed 
will preferably remain in the reactor for a time in the range of about 0.1 
hours to about 5 hours and more preferably from about 0.25 hours to about 
3 hours. 
The hydrovisbreaking process can be carried out at any suitable 
temperature. The temperature will generally be in the range of about 
250.degree. C. to about 550.degree. C. and will preferably be in the range 
of about 380.degree. to about 480.degree. C. 
Any suitable hydrogen pressure may be utilized in the hydrovisbreaking 
process. The reaction pressure will generally be in the range of about 
atmospheric to about 10,000 psig. Preferably, the pressure will be in the 
range of about 500 to about 3,000 psig. Higher hydrogen pressures tend to 
reduce coke formation but operation at high pressure may have adverse 
economic consequences. 
Any suitable quantity of hydrogen can be added to the hydrovisbreaking 
process. The quantity of hydrogen used to contact the feed plus solvent, 
either in a continous or batch process, will generally be in the range of 
about 100 to about 20,000 standard cubic feet per barrel of the feed plus 
solvent and will more preferably be in the range of about 500 to about 
5,000 standard cubic feet per barrel of the feed plus solvent. 
Referring now to FIG. 2, like numbers refer to like equipment in FIG. 1. 
However, in FIG. 2 a portion of the atmospheric topped crude is provided 
through conduit 31 as a solvent for the hydrovisbreaking process 21. 
Again, any suitable amount of the atmospheric topped crude may be provided 
to the hydrovisbreaking process 21. The amount will generally be limited 
by the size of the vessels used in the hydrovisbreaking process 21. The 
amount of the atmospheric topped crude utilized will generally be in the 
range of about 5 weight percent to about 95 weight percent based on the 
total weight of the solvent extracted topped crude and the atmospheric 
topped crude provided to the hydrovisbreaking process 21. 
FIG. 3 illustrates a crude oil fractionating process in which solvent 
extraction is not utilized. In FIG. 3, for the same volume of full range 
crude used in a process such as illustrated for FIG. 1, a larger 
hydrovisbreaking process would be required because of the increased volume 
of the feed to the hydrovisbreaking process (the volume of the vacuum 
topped crude is greater than the volume of the solvent extracted topped 
crude). 
Again, a portion of the full range crude is provided as a solvent to the 
hydrovisbreaking process in the same manner as illustrated for FIG. 1. Any 
suitable amount may be supplied as a solvent. The amount of the full range 
crude provided to the hydrovisbreaking process as a solvent will generally 
be in the range of about 5 weight percent to about 95 weight percent based 
on the total weight of the vacuum topped crude and full range crude 
provided to the hydrovisbreaking process 21. 
FIG. 4 is a variation of FIG. 3 in which the atmospheric topped crude is 
employed as a solvent for the hydrovisbreaking process 21. Again, any 
suitable amount of the atmospheric topped crude may be utilized as a 
solvent. The amount of the atmospheric topped crude provided to the 
hydrovisbreaking process will generally be in the range of about 5 weight 
percent to about 95 weight percent based on the total weight of the vacuum 
topped crude and atmospheric topped crude provided to the hydrovisbreaking 
process 21. 
The following example is presented in further illustration of the 
invention: 
EXAMPLE 1 
A California heavy vacuum topped crude, (Hondo crude cut of 1000+.degree. 
F. boiling range) was batch hydrovisbroken in a 300 cc autoclave under 
four conditions: 
(1) Hondo vacuum topped crude (1000+.degree. F.) was hydrovisbroken without 
any added solvent. 
(2) Hondo vacuum topped crude (1000+.degree. F.) was hydrovisbroken with 
about 20 weight percent Tetralin added as a solvent for the 
hydrovisbreaking. 
(3) Hondo vacuum topped crude (1000+.degree. F.) was hydrovisbroken with 
about 50 weight percent of novel solvent which was a Hondo atmospheric 
topped crude cut of 650+.degree. F. boiling range. 
(4) Hondo vacuum topped crude (1000+.degree. F.) was hydrovisbroken with 
about 50 weight percent of novel solvent which was a full range raw Hondo 
crude undistilled. 
The conditions and results are tabulated in Table I as follows. 
TABLE I 
__________________________________________________________________________ 
Conventional 
Novel Novel 
Test Base Case 
Solvent 
Solvent 
Solvent 
__________________________________________________________________________ 
Oil cut, .degree.F. 
Hondo 1000+ 
Hondo 1000+ 
Hondo 1000+ 
Hondo 1000+ 
Solvent None Tetralin 
Hondo 650+ 
Hondo Full Range 
Oil charge, gms 
142.9 
78.4 56.3 30.9 
solvent charge, gms 
0 20.3 57.5 84.8 
H.sub.2 pressure psig 
950 1000 1000 995 
Temperature .degree.F. 
798 800 801 785 
Residence Time Minutes 
60 60 60 60 
Mo additive Molyvan L 
Molyvan L 
Molyvan L 
Molyvan L 
Mo charge, ppm* 
390 400 420 130 
Results: 
Solids make wt % 
18.02 
4.25 9.42 6.92 
1000+.degree. F. conversion 
83.66 
71.13 83.37 69.63 
wt. % 
__________________________________________________________________________ 
*PPM Mo based on sum of oil feed plus solvent. 
Molyvan.RTM. L is a mixture of about 80 weight-% of a sulfided molybdenum 
(V) dithiophosphate of the formula Mo.sub.2 S.sub.2 O.sub.2 [PS.sub.2 
(OR).sub.2 ], wherein R is the 2-ethylhexyl group and about 20 weight-% of 
an aromatic oil (marketed by R. T. Vanderbilt Company). 
The results in Table II show that the use of the Hondo 650+.degree. F. cut 
as a solvent result in more solids make than the use of Tetralin as a 
solvent but resulted in much less solids than if no solvent at all were 
used. In additional the use of the Hondo 650+.degree. F. cut also resulted 
in more conversion than was achieved with the Tetralin solvent. Use of the 
Hondo 650+.degree. F. cut as a solvent is much more economical than the 
use of a solvent such as Tetralin. 
The use of the full range crude at less favorable conditions (lower 
hydrogen pressure and lower temperature) also resulted in more solids make 
than the Tetralin solvent but less solids make than the atmospheric topped 
crude. Conversion was lower for the full range crude but this can be 
accounted for by the less favorable conditions. Again, the economics of 
using the full range crude would be favorable as opposed to a solvent such 
as Tetralin. 
Reasonable variations and modifications are possible within the scope of 
the disclosure and the appended claims to the invention.