Note: Descriptions are shown in the official language in which they were submitted.
3~
- P~OC~SS FOR VIS-BRE~KI~G ASPHALTENES
BACKGROUND OF THE INVENTIO~i
FIELD OF THE INVENTION
~his invention relates to a process for separa-
ting a fraction substantially comprising asphaltenes from
heavy hydrocarbon materials and then treating the separa-
ted fraction to crack and vis-brea~ the same to produce
10 additional liquid products having a reduced metals content.
BRIEF DESCRIPTION OF THE PRIOR ART
Many methods of extracting various fractions
from biturninaus materials have been disclosed previously
:in the prior art. Perhaps the most well known of these
lS is termed "propane extraction" in which asphaltic mate-
rials are separated from heavy hydrocarbons to produce de-
asphalted oils and an asphaltene-containing residue by
means of a single solvent extraction step using propane as
the extractant.
In that it is desirable to obtain the greatest
possible quantity of oils from a heavy hydrocarbon mate-
rial such as a reduced crude, other extraction techniques
have been developed. U.S. Pat. 2,940,920, assigned to the
present applicant, discloses a process capable o~ effecting
25 a deeper cut in heavy hydrocarbon materials than is avail-
able by means of propane extraction. That patent discloses
- Pffecting the separation by using high temperature-pressure
techniques and by using pentane as one of a group of suit-
able solven-ts. Such practice permits a deeper cut to be
30 made in the heavy hydrocarbon material and produces an
asphaltene-containing residue having a higher viscosity
than that produced by propane extraction.
Normally, the asphaltene-containing residue also
w:ill contain a substantial portion of any organometallic
35 compounds which are present in the heavy hydrocarbon mate-
rlal. This residue, because of its high viscosity and
meta:ls con-tent, has limited commercial u-tility. The resi-
due can be used as a soil conditioner, asphalt hardener,
33~
--2--
printing ink pigment, paper sizing agent and solid granular
insulator. The physical and chemical properties of the
residue substantially limit its use as a liquid fuel even
when diluted with hydrocarbon cutter stocks.
It would be desirable to convert -the asphaltene-
containing residue into lighter products by vis-breaking
or thermal pyrolysis under controlled conditions to accep-
table lower viscosity products suitable for use as liquid
10 fuels. Various processes for vis-breaking heavy hydrocar-
bon materials by thermal pyrolysis are disclosed in U.S.
Patents: 2,695,264; 2,900,327; 3,234,118 and 3,3~9,024.
Prior attempts to produce liquid products from
asphaltenes have had limited success. When an attempt has
15 been made to vis-break or thermally pyrolyze the asphal-
tenes, coking has occurred in the process equipment~ Coking
occurs when a feed is not maintained in a turbulent flow
condition within the process equipment at the high temper-
atures at which the equipment operates. The high viscosity
20 of the asphaltenes impedes maintaining the same in the
turbulent flow condition necessary to prevent coking.
This results in a low yield of desired vis-broken product
and a short on-stream time before coking of the feed causes
a termination of process operation. The coke then must be
25 removed from the equipment manually or by burnout with
injected air.
~- SU~ARY OF THE INVENTION
The discovery now has been made that it is poss-
ible to treat a heavy hydrocarbon material by the process
30 hereinafter described to effect a deep oil cut in the
heavy hydrocarbon material and then treat the asphaltene-
eontaining residue by vis-breaking under controlled condi-
tions to produee additional liquid products while elimina-
ting or substantially reducing coking in the vis-bre~!king
35 equi~ment.
The process comprises contacting the heavy hydro-
carbon material with a first solvent in a mixing zone to
provide a mixture for introduction into a first separation
33~
zone. The first separation zone is maintained a~ an ele-
vated temperature and pressure to effect a separation of
the mixture into a fluid-like first light phase comprising
first solvent, oils and resins and a fluid-like first heavy
phase comprising asphaltenes containing the bulk of the
organometallic compounds present and some first solvent.
The first light phase is withdrawn from the first separa-
ation zone and introduced into a second separation zone for
10 additional fractionation or recovered as a product.
The first heavy phase then is introduced into a
vis-brea]~ing zone in which il is heated to an elevated tem-
perature under high pressure to effect thermal cracking of
-the asphaltenes. The pressure in the vis-breaking zone
15 is sufficient to prevent the formation of any separate
vapor phase at the highest temperature within said vis-
breaking zone. The products of the vis-breaking zone are
withdrawn from the zone as a single condensed phase and
introduced into a third separation zone.
In the third separation zone, the vis-breaking
zone products are flashed in one or more stages, the last
stage preferably being under vacuum to separate at least a
portion of any distillable liquid and gaseous products
including first solvent from any substantially nondistill-
25 able liquid products and residue. The remainder then is
contacted with a second solvent and introduced into a
four-th separation zone that is maintained at an elevated
-temperature and pressure.
- The remainder separates within the fourth separa-
30 tion zone into a fourth light phase comprising a liquid
product comprising substantially nondistillable products,
any distillable produc-ts and second solvent and a fourth
heavy phase comprising the residue which comprises residual
asphaltenes, organometallic compounds, coke, catalyst fines,
35 iE any, and other heavy carbonaceous materials. The fourth
light phase is withdrawn from the fourth separation zone
and introduced into a fifth separation zone.
~IEil3~
-4-
The ~ifth separation zone is maintained
under suitable conditions o~ temperature and pressure
to effect a separation of the fourth light phase into
a fifth light phase comprising second solvent and a
~ifth heavy phase comprising liquid products of the
vis-bre.a~ing process. The second solvent is recycled
in the process and the vis-breaking liguid products
are recovered for use as a liquid fuel having a
reduced metals content.
Accordingly, one principal Pmbodiment of
the invention provides for a process comprising:
introducing a heavy hydrocarbon material comprising
oils, resins, asphaltenes and associated
organometallic compounds and a fir~t solvent into a
first separation ~one maintained at an elevated
temperature and pressurP level to effect a separation
of said heavy hydrocarbon material and first solvent
inko a first lignt phas~ including first solvent and
a first heavy phase comprising asphaltenes,
organometallic compounds and some ~irst solvent;
recovering first solv~nt from said ~irst light phase
in a second separation zone; introducing said ~irst
heavy phase into a vis-breaking zone maint~;ne~ at an
alavated temperature and pressure lavel to crack sa.id
asphaltenes in said ~irst heavy phase to produce
distillable and substantially nondistillable liquid
vis-broken products including organometallic
compounds, said pressure level being such that
substantially a single condensed phase exists within
said vis-breaXing zone: introducing said distillable
and substantially non-distillable li~uid products
from said vis-breRklng zone into a third separation
zone to separate at least a portion o~ said
~'.
3~3
-4a-
distillable liquid products from the remainder:
introducing said remainder from said third separation
zone and a second solvent into a fourth separation
zone maintained at an elevated temperature and
5 pres~ure to effect a ~eparation of said mixture into
a ~ourth light phase comprising nondistillable li~uid
products substantially free of organometall.ic
compounds, any distillable liquid products present
and second solvent and a fourth heavy phase
comprising a residue including organometallic
compounds and some second eolvsnt; and recovering
said fourth light phase.
Another principal embodiment of the
invention provides a process comprising: introducing
a heavy hydrocarbon material comprising oils, resins,
asphaltenes and associated organometallic compounds
and a first solvent into a fir~t separation zone
maint~ine~ at an elevated temperature and pressure
level to effect a separation of said hPavy
20 hydrocarbon material and first solvent into a ~irst
light phase including first solvent and a first heavy
phase comprising asphaltenes, oryan~metallic
compounds and some first solvent, recovering ~irst
solvent from said first light phase in a second
separation ~one; a~ ing said ~irst heavy phase with
a diluent comprising a hydrocarbon to ~orm a mixture;
introducing said mixture into a vis-breaking zone
maintained at an elevated temperature and pressure
level to crack said asphaltenes in said first heavy
30 phase to produce distillable ~nd substantially
non-distillable liquid vis-broken products including
said organometallic compounds in association with
-4b-
said diluent, said pressure level within said
vis-breaking zone being sufficient that substantially
a single condensed phase exists within said
vis-breaXing zone; separating at least a portion of
said diluent and distillable liquid products from
said substantially nondistillable liquid products;
introducing said substantially nondistillable liquid
products and a second solvent into a third separation
zone maint~ne~ at an elevated temperature and
1~ pressure level to effect a separation of said same
into a third li~ht phase comprising substantially
nondistillable liquid products substantially free of
organometallic compounds and second solvent and a
third heavy phase c~mprising a residue including
organometallic compounds; and recovering said
substantially non~i ctillable li~uid products of said
third light phase.
A third principal embodiment provides a
process comprising: a~' ;~;n~ a hydrocarbon material
comprising asphaltenes and associated organometallic
compounds with a diluent to form a mixture;
introducing said mixture into a vis-breaking zone
maintained at an elevated temperature and prassure
level to crack said asphaltenes in said mixture to
2~ produce vis-br~k;n~ products comprising distillable
and substantially nondistillable liquid vis-broken
products including said organometallic compounds in
association with said diluent, said pressure level
within said vis-breaking zone being su~ficient that
substantially a single condensed phase exists within
said vis-bre~k~ ng zone; separating at least a portion
of said diluent and distillable liquid products from
said substantially nondistillable liquid products o~
3~
-4c-
said vis-breaking; a~ ;ng said substantially
nondistillable li~uid products with a solvent to form
a second mixture; introducing ~aid second mixture
into a separation zone maintained at an elevated
temperature and pr~ssure level to effect a sPparation
of said second mixture into a light phase comprising
~ubstantially nondistillable liquid products
substantially free of organometallic compounds and
~olvent and a heavy phase comprising a residue
including said organometallic compounds; and
recovering said substantially nondistillable liquid
products of said light phase.
BRIEF DESCRIPTON OF THE DRAWING
The ~ingle drawing is a diagramatic
illustration of the process of this in~ention.
DESCRIPTION OF THE ~R~KK~D EMBODIMENT
Turning now to th. drawing, the process of
the present invention is illustrated. A feed ~tock
comprising a heavy hydrocarbon material com~rising
asphaltene~ and either or both rasins ~nd oils is
introduced into a mixing zone 12 through a conduit
lO. A first ~olvent is introduced into mixing zone
12 through a conduit 12 to contact and admix with the
feed to provide a mixture. Sufficient first ~olvent
is introduced into m;~;ng zone 12 to provide a ratio
by volume (measured at ambient temperature
conditions) of solvent to feed in the mixture in the
range of from about 2:1 to about 20:1 and preferably
in the range of from about 8:1 to about 12:1. It is
to be understood that larger quantitie~ of the first
solvant may be used, but such use is not particularly
advantageous.
.
3g~
4d-
The term "first solvent" as used herein
means a fluid comprising at least one member selected
from the group consisting of: paraffin hydrocarbons
containing from 4 through 9 carbon atoms, such as
pantane, hexane, heptane, octane and nonane,
cycloparaffin hydrocarbons contAin;ng fewer than 10
carbon atoms, such as, cyclopentane, cyclohexane and
their methyl derivatives; mono-olefin hydrocarbons
containing from 4 through 8 carbon atoms/ such as
butene, pentene, hexene, heptene and oct~ne and any
other fluid known to those skilled in the art which
is capable of
3~
dissolving at least a portion of the heavy hydrocarbon
material feed and then is capable of separation from said
dissolved feed.
The mixture then is passed into a first separa-
tion zone lB via a conduit 16. The first separation
zone 18 is maintained at an elevated temperature and
pressure to effect a separation of the mixture into a
fluid-like first light phase comprising first solvent, oils
~0 and resins and a fluid-like first heavy phase comprising
asphal-tenes, organometallic compounds and some first solv-
ent. As previously indicated, a substantial portion of
the organometallic compounds present in the heavy hydro-
carbon material are associated with the asphaltenes.
More particularly, first separation zone 18 is
maintained at a temperature level in the range of from
about 150F. to about the critical temperature of the
first solvent and a pressure level at least equal to the
vapor pressure of the first solvent when at a tempera-
20 ture below the critical temperature of the first solvent
and at least equal to the critical pressure of the first
solvent when at a temperature equal to or above the criti-
cal temperature of the first solvent. Preferably, the
temperature level is maintained within a range of from
25 about 50 F. below the critical temperature of the first
solvent to about 50F. above the critical temperature of
the first solvent. Preferably, the pressure level is main-
tained at or above the critical pressure of the first solv-
ent.
Alternatively, the heavy hydrocarbon material and
Eirst solvent can be introduced directly into Eirst separa-
tio~ zone 18 in the ratios previously described but at
diEferent points -therein, without prior admixing and then
the separation can take place as previously described.
The first light phase is withdrawn from first
separation zone 18 through a conduit 20 and recovered. In
one embodiment~ the separated first light phase is passed
from first separation zone 18 through conduit 20 and intro-
duced into a second separation zone 22. The second separa-
tion zone 22 is maintained at a temperature level higher
than the temperature level in the first separation zone 18
and at an elevated pressure to efEect a separation of the
first light phase into a fluid-like second light phase
comprising oil, resins and some first solvent. Preferably,
the temperature level in second separation zone 22 is main-
lQ tained in a range of from about 5F. to about 100F. abovethe temperature in first separation zone 18 and most pre-
~erably at a temperature of from about 5F. to about 50F.
above the critical temperature of the solvent.
The pressure level of second separation zone 22 is
15 maintained at least equal to the vapor pressure of the first
solvent when zone 22 is maintained at a temperature below
the critical temperature of the first solvent and at least
equal to the critical pressure of the first solvent when
maintained at a temperature equal to or above the critical
20 temperature of the first solvent. The pressure level in
second separation zone 22 can be substantially the same as
is maintained in first separation zone 18.
The second light phase is withdrawn from second
separation zone 22 through a conduit 26 for recycle in the
25 process to contact additional fresh feed. The second heavy
phase can be introduced into an individual stripping zone
~not shown) to strip at least a portion of any first solv-
ent that may be contained therein. Preferably, the stripp-
ing zone comprises a steam stripping vessel. The Eirst
30 solvent thus recovered by stripping can be recycled in
the process. The second heavy phase is withdrawn from
second separation zone 22 through a conduit 24 and, after
being freed of any contained first solvent, is recovered
Eor beneEicial use, for example, as liquid fuel or as
35 Eeedstock to a hydrotreating process.
The first heavy phase is withdrawn from first
separation zone 18 through a conduit 28 and introduced into
a vis-breaking zone 30. In vis-breaking zone 30l the first
-7
heavy phase is heated to a temperature above 850F. while
being maintained at an elevated pressure to effect a con-
v~r~i~on of the asphaltenes into lower molecular weight
fragments. Preferably the temperature level is maintained
above 900-F. and most preferably above 950F. to effect an
efficient cracking of the asphaltenes. The pressure level
is controlled such that the pressure of the first heavy
phase entering vis-breaking zone 30 and the pressure level
10 of the products exiting zone 30 are both above the minimum
pressure level required to prevent the formation of any
separate vapor phase at any operating temperature level
within zone 30. Such control of the pressure level pre-
vents the formation of excessive amounts of coke and gas
15 ~ithin vis-breaking zone 30 by substantially limiting the
~egree of degradation of the vis-breaking zone products.
This control is monitored by measuring the pressure drop
of the first heavy phase during its passage through vis-
breaking zone 30 at temperatures below the cracking temp-
20 erature of the asphaltenes and at temperatures above thecracking temperature of the asphaltenes. The pressure drop
under these two different conditions is substantially lm-
changed when only a single condensed phase exists within
zone 30. An increase in the pressure drop through zone 30
25 at temperatures above the cracking temperature of the asphal-
tenes indicates that a separate vapor phase is forming and
that excess coke formation also probably has occurred.
The first heavy phase in vis-breaking zone 30 is
converted into vis-breaking products comprising condensed
30 hydrocarbon gases, if any are produced, distillable liquid
products and substantially nondistillable liquid products
`,including orgarlometallic compounds. The vis-breaking pro-
ducts then pass from vis-breaking zone 30 through a conduit
32 into a third separation zone 34.
In third separation zone 34, the vis-breaking pro-
clucts are Elashed to separate at least a portion of any
gaseous and distillable liquid products including first
solvent from the substantially nondistillable liquid pro-
ducts. The separated portion is withdrawn from third
separation zone 34 through a conduit 36 and recovered.
The separated first solvent can be recycled to first sepa-
ration zone 18.
In an alternate embodiment of the present inven-
tion, the first heavy phase in conduit 2~ can be treated
(not shown) to separate at least a portion of any first
10 solvent present for recycle to mixing zone 12. The removal
of Eirst solvent from the first heavy phase will cause a
siynificant increase in the viscosity of the remaining
asphaltenes and organometallic compounds in the first
heavy phase. To facilitate cracking of the asphaltenes in
15 the first heavy phase in vis-breaking zone 30, a diluent is
added to -the asphaltenes and organometallic compounds to
reduce the viscosity of the mixture prior to entry into
zone 30. The diluent is introduced into the mixture in
conduit 28 through a conduit 56 in a quanti~y sufficient to
~0 reduce the viscosity of the mixture to a level at which it
is easily flowable.
The diluent that is employed in practicing the
invention is a highly aromatic petroleum by-product stream
having a boiling temperature range of from about 400F. to
25 about 1000F~ The diluent can comprise a catalytic cracker
. recycle stock such as light catalytic cracker recycle oil,
heavy catalytic cracker recycle oil or catalytic cracker
slurry oil, thermally cracked petroleum stocks and lubrica-
ting oil aromatic extracts. Preferably the diluent will
30 have a boiling temperature range of from about 400F~ to
about 800F. and most preferably a range of from about
~00 F. to about 650 ~.
The diluent imparts fluidity to the mixture of
asphaltenes and organometallic compounds and facilitates
35 heating of the mixture to the high temperatures necessary
for cracking of the asphaltenes without an excessive pro-
duction of coke, gases or light molecular fragments. The
3~3
g
diluent generally is not itself thermally degraded in the
vis-breaking process because it already is a product of
a previous high temperature catalytic cracking conversion
process. Catalytic cracker slurry oil is a particularly
satisfac-tory diluent since it normally contains catalyst
fines which act within vis-breaking zone 30 to improve the
cracking rate and decrease those side reactions which tend
to result in the formation of coke and gaseous products.
10 The catalyst fines also tend to adsorb any metal values and
other contaminants that may be released from the asphaltenes
and organometallic compounds during the vis-breaking process.
The vis-breaking products and diluent are with-
drawn from vis-breaking zone 30 and introduced into third
15 separation zone 34 through conduit 32. The gases 7 distill-
able liquid products and diluent then are separated from
the substantially nondistillable liquid products and organo-
metallic compounds and withdrawn through conduit 36. A
portion of diluent in conduit 36 can be recycled through a
20 conduit 38 to contact fresh feed to vis-breaking ~one 30.
In yet another embodiment of the present inven-
tion, in the event that the quantity of first solvent pre-
sent in the first heavy phase is insufficient to provide
the fluidity necessary for processing of the asphaltenes
25 in vis-breaking zone 30, the diluent can be added to the
first heavy phase without prior separation of the first
solvent. The mixture of first heavy phase and dihuent then
is -treated as previously described and the first solvent is
recovered along with the diluent in third separation zone 34.
Irrespective of the operation of vis.-breaking zone
30, the third heavy phase is withdrawn from third separation
zone 34 through a conduit 40, contacted with a second solvent
introduced through a conduit 42 and introduced into a fourth
separation zone 44.
The second solvent is introduced in a quantity
sufficien-t to provide a ratio of solvent to th~rd heavv
phase in -the range of from about 2:1 to about 10:1. It is
-10-
to be understood that larger quantities of the second sol-
vent can be used, but such use is not particularly advan-
tageous.
While specific reference has been made to a second
solvent, it is to be understood that the second solvent can
be the same as the first solvent or comprise any other fluid
suitable for use as the first solvent.
In fourth separation zone 44, the mixture of third
lO heavy phase and second solvent is separated into a fourth
liqht phase co~nprising substantially nondistillable liquid
products of the vis-breaking operation substantially free
of organometallic compounds and second solvent and a fourth
heavy phase comprising a residue which comprises res~dual
15 asphaltenes, organometallic compounds, coke, catalyst fines,
if any, and other heavy carbonaceous materials.
More particul~rly, fourth separation zone 44 is
maintained at a temperature level in the range of from
150F. to about the critical temperature of the second sol-
20 vent and a pressure level at least equal to the vapor pres-
sure of the second solvent when at a temperature below the
critical temperature of the second solvent and at lea~t
equal to the critical pressure of the second solvent when
at a temperature equal to or above the critical temperature
25 of the second solvent. PreferaDly, the temperature level
is maintained within a range of from about 50F. below the
critical temperature of the second solvent to about 50F.
above the critical temperature of the second solvent. Pre-
ferably, the pressure level is maintained on above the
30 critical pressure of the second solvent.
The four-th heavy phase is withdrawn from fourth
separation zone 44 through a conduit 50 for recovery. The
fourth heavy phase can be used as a solid feed to a gasifier
or otherwise treated prior to disposal.
The four-th light phase is withdrawn from fourth
separation zone 44 -through a conduit 46 and introduced into
a Eifth separation zone 48. In fifth separation zone 48, the
fourth light phase is maintained at an elevated temperat~lre
3~
and pressure to effect a separation into a fifth light phase
comprising second solvent and a fifth heavy phase comprising
liquid products of the vis-breaking operation and some
second solvent. The temperature level of fifth separation
zone 48 is maintained at a level higher than the temperature
level wlthin fourth separation zone 44. The pressure level
of fifth separation zone 48 is maintained at least equal to
the vapor pressure of the second solvent when zone 48 is
10 maintained at a temperature below the crltical temperature
of the second solvent and at least equal to the critical
pressure of the second solvent when maintained at a tempera-
ture equal to or above the critical temperature of the sec-
ond solvent. More particularly, the temperature level in
15 fifth separation zone 48 preferably is maintained above the
critical temperature of the second solvent and most prefer-
ably from about 5F. to about 50F. above the critical tem-
perature of the secona solvent.
The separated fifth light phase is passed from
20 fifth separation zone 48 through a conduit 52 recycle in the
process.
The ~ifth heavy phase is withdrawn from fif-th
separation zone 48 through a conduit 54 and recovered for
use as a liquid fuel generally being equivalerlt in utility
25 to No. 6 fuel oil.
The fourth and fifth heavy phases can be:intro-
duced into individual stripping zones (not shown) to strip
at least a portion of any second solvent that may be con-
tained in the respective heavy phases. Preferably the strip-
30 ping zones would comprise steam stripping vessels. Thesecond solvent -then can be recycled in -the process.
In an alternate embodiment of the present inven-
tion, fifth separation zone 48 can comprise a flash zone in
which the fourth light phase is flashed to a sufficiently
35 reduced pressure to form at least one stream comprising the
liquid products of the vis-breaking operation and one other
stream comprising second solvent. The liquid products then
are recovered and the solvent is recycled as previously
desc~ibed.
To further illustrate the process o~ this inven-
tion and not by way of limitation, the following examplesare provided.
EXAMPLE I
A recluced crude comprising 18 percent asphaltenes,
30 percent resins and 52 percent oils, by weight, having a
10 soFtening point of about 110F., is admixed with a first
so~ven-t comprising n-pentane in a volume ratio (measured
at 60F.) oE solvent to feed of about 10:1 and introduced
into a first separation zone 18. The first separation zone
is maintained at a temperature level of about 370F. and a
15 pressure level of about 650 psig. ~he feed mixture separa-
tes into a first light phase and a first heavy phase compri-
sing asphaltenes and some n-pentane.
The n-pentane is separa-ted from the first heavy
phase by flashing and the remainder of the heavy phase is
20 admixed with a diluent comprising catalytic cracker slurry
oil in a ratio of diluent to feed of about ,:1 to form a
mixture which is introduced into a vis-breaking zone 30.
The mixture is heated to a temperature of about 950 Fo in
vis-breaking zone 30 while maintained at a pressure level
25 of about 500 psig. to prevent the formation of a separate
vapor phase within vis-breaking zone 30. The~products of
the vis-breaking zone are introduced into a third separa-
-tion zone comprising a flash zone to separate distillable
liquid products from-any..substantially nondistillable liquid
30 products and organometallic compounds. The nondistillable
liquid products and organometallic compounds then are con-
tacted with a second solvent comprising n-hexane in a ratio
of solvent to Eeed of about 8:1 to form a mixture that is
introduced in-to a fourth separation zone 44.
The fourth separation zone is maintained at a tem-
perature level of about 450F. and a pressure level of about
650 psig. to effect a separation of the mixture present
-13-
therein into a fourth light phase and a fourth heavy phase
comprising a residue including organometallic compounds.
The fourth ligh-t phase then is introduced into a fifth
separation zone ~8 comprising a flash zone wherein the
pressure level on the fourth light phase is reduced to
about atmospheric pressure to vaporize the second solvent
and form a stream of liquid products. The liquid products
have a reduced metals content and are comparable in quality
lO to a No. 6 fuel oil.
EXAMPLE II
The reduced crude of Example I is admixed with a
first solvent comprising cyclohexane in a volume ratio of
5 olvent to feed of 20:1 and introduced into first separa-
15 tion zone 18. The first separation zone is maintained at
a temperature level of about 500F. and a pressure level
of about 650 psig. The feed misture separates into a first
light phase and a first heavy phase comprising asphaltenes
and some pentane.
The first heavy phase then is admixed with a
diluent comprising catalytic cracker slurry oil in a ratio
of diluent to feed of about 3:1 to form a mixture which is
introduced into a vis-breaking zone 30. The mixture is
heated to a temperature of about 950 E. in vis-breaking
25 zone 30 while maintained at a pressure level of about 500
.. psig. to prevent the formation of a separate vapor phase
within vis-breaking zone 30. The products of vis-breaking
zone 30 then are introduced into a third separation zone
comprising a flash zone to separate distillable liquid
30 products and organometallic compounds. The nondistillable
liquid products and organome-tallic compounds then are cont-.
acted with a second solvent comprising benzene in a ratio
o;E solvent to feed of about 7:1 to form a mixture that is
introduced into a fourth separation zone 44.
The fourth separation zone is maintained at a
temperature level of about 545 F. and a pressure level of
about 750 psig. to effect a separation of the mixture in~o
-14-
a fourth light phase and a fourth heavy phase comprising
a residue including organometallic compounds. The fourth
light phase then is introduced into a fifth separation zone
maintained at a temperature level of about 575F. and a
pressure level of about 725 psig. The fourth light phase
is caused to separate into a fifth light phase comprising
second solvent and a fifth heavv phase comprising liquid
products of the vis-brea~ing operation and some second
10 solven-t. The fifth heavy phase then is steam stripped to
separate the remaining second solvent from the liquid pro-
ducts. The liquid products have a reduced metals content
and are comparable in quality to a No. 6 fuel oil.
The foregoing examples illustrate the means by
15 which the present invention can be used to increase the
yield of useful liquid products recovered from a he~vy
hydrocarbon material.
The term "heavy hydrocarbon material" as used
herein means pyrogenous bitumens, native bitumens or one
20 or more fractions or components thereof. The pyrogenous
bitumens include heavy or very low API gravity petroleum
crudes, reduced crudes, either steam or vacuum refined, hard
and soft wood pitches, coal tar residues, cracked tars, tall
oil and the like. The native bitumens include gilsonite,
25 wurtzilite, albertite and native asphalt, for instance,
Trinidand asphalt and the like.
~ The term "liquid phase product" as used herein
means a product that exhibits a characteristic readiness
-to flow at process conditions.
While the invention has been described with re-
spect -to what at present are preferred embodiments thereof,
it will be understood, of coursej that certain changes,
subs-titutions, modifications ano the like may be made
therein without departing from its true scope as defined
35 in the appended claims.
