U.S. patent application number 11/996251 was filed with the patent office on 2008-09-04 for high quality asphalt containing pitch and method of preparing the same.
This patent application is currently assigned to SK Energy Co., Ltd.. Invention is credited to Soon Man Cha, Yoon Mang Hwang, Cheol Joong Kim, Gyoo Tae Kim, Ki Byung Kim, Myung Jun Kim, Sung Bum Park, Ik Sang Yoo.
Application Number | 20080210597 11/996251 |
Document ID | / |
Family ID | 37669018 |
Filed Date | 2008-09-04 |
United States Patent
Application |
20080210597 |
Kind Code |
A1 |
Yoo; Ik Sang ; et
al. |
September 4, 2008 |
High Quality Asphalt Containing Pitch and Method of Preparing the
Same
Abstract
A high quality asphalt containing pitch is generated as a
by-product in a solvent deasphalting process and a method of
preparing the same. The pitch is obtained by subjecting a mixture
comprising a first vacuum residue and a first petroleum distillate,
which is lighter than the vacuum residue and has high amounts of
aromatic and resin, to solvent deasphalting. The operation
conditions of the solvent deasphalting process are appropriately
controlled, such that aromatic and resin components contained in
the atmospheric residue and vacuum residue can be distributed to
the pitch, and as well, a saturate can be removed.
Inventors: |
Yoo; Ik Sang; (Daejeon,
KR) ; Kim; Myung Jun; (Daejeon, KR) ; Cha;
Soon Man; (Daejeon, KR) ; Kim; Gyoo Tae;
(Daejeon, KR) ; Kim; Cheol Joong; (Daejeon,
KR) ; Kim; Ki Byung; (Daejeon, KR) ; Park;
Sung Bum; (Daejeon, KR) ; Hwang; Yoon Mang;
(Daejeon, KR) |
Correspondence
Address: |
DARBY & DARBY P.C.
P.O. BOX 770, Church Street Station
New York
NY
10008-0770
US
|
Assignee: |
SK Energy Co., Ltd.
Seoul
KR
|
Family ID: |
37669018 |
Appl. No.: |
11/996251 |
Filed: |
July 19, 2006 |
PCT Filed: |
July 19, 2006 |
PCT NO: |
PCT/KR2006/002845 |
371 Date: |
January 18, 2008 |
Current U.S.
Class: |
208/41 |
Current CPC
Class: |
C10G 2300/1077 20130101;
C10C 3/005 20130101; C10G 2300/4025 20130101; C10G 21/003 20130101;
C10G 2300/107 20130101; C10G 2300/44 20130101; C10G 2300/1074
20130101; C10C 3/00 20130101 |
Class at
Publication: |
208/41 |
International
Class: |
C10C 3/06 20060101
C10C003/06 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 20, 2005 |
KR |
10-2005-0065765 |
Claims
1: A high quality asphalt containing pitch, the pitch being
obtained by subjecting a mixture comprising a first vacuum residue
and a first petroleum distillate, which is lighter than the vacuum
residue and has high amounts of aromatic and resin, to solvent
deasphalting.
2: The asphalt according to claim 1, wherein a mixing ratio of the
vacuum residue to the petroleum distillate is 10-90 wt %.
3: The asphalt according to claim 1, further comprising a second
vacuum residue, a second petroleum distillate, or a mixture of the
second vacuum residue and the second petroleum distillate.
4: The asphalt according to claim 1, wherein the first petroleum
distillate comprises at least one selected from the group
consisting of an atmospheric residue, a heart cut vacuum gas oil,
and a slurry oil for fluid catalytic cracking.
5: The asphalt according to claim 3, wherein the second petroleum
distillate comprises at least one selected from the group
consisting of an atmospheric residue, a heart cut vacuum gas oil,
and a slurry oil for fluid catalytic cracking.
6: The asphalt according to claim 1, wherein the pitch has
penetration substantially equal to or lower than that of the vacuum
residue.
7: A method of preparing high quality asphalt containing pitch,
comprising conducting crude distillation and vacuum distillation to
produce a vacuum residue for use in preparation of the asphalt, the
method using the pitch obtained by subjecting a mixture of a first
vacuum residue, produced through the vacuum distillation, and a
first petroleum distillate, which is lighter than the vacuum
residue and has high amounts of aromatic and resin, to solvent
deasphalting.
8: The method according to claim 7, wherein a mixing ratio of the
first vacuum residue to the first petroleum distillate is 10-90 wt
%.
9: The method according to claim 7, wherein the solvent
deasphalting requires a solvent selected from C3-C4 paraffin
solvents and mixtures thereof, and a yield of the pitch is 10-90
vol %.
10: The method according to claim 7, wherein the solvent
deasphalting is conducted at a pitch extraction temperature of
43.about.93.degree. C. in the presence of n-propane or
115.about.150.degree. C. in the presence of n-butane/iso-butane at
a pitch extraction pressure of 30-46 kg/cm.sup.2 g, and the pitch
produced through the solvent deasphalting has penetration
substantially equal to or lower than that of the vacuum residue
used in the solvent deasphalting.
11: The method according to claim 7, further comprising mixing the
pitch with a second vacuum residue, a second petroleum distillate,
or a mixture of the second vacuum residue and the second petroleum
distillate.
12: The method according to claim 7, wherein the first petroleum
distillate comprises at least one selected from the group
consisting of an atmospheric residue, a heart cut vacuum gas oil,
and a slurry oil for fluid catalytic cracking.
13: The method according to claim 11, wherein the second petroleum
distillate comprises at least one selected from the group
consisting of an atmospheric residue, a heart cut vacuum gas oil,
and a slurry oil for fluid catalytic cracking.
Description
TECHNICAL FIELD
[0001] The present invention relates, generally, to high quality
asphalt containing pitch that is generated as a by-product in a
solvent deasphalting process and a method of preparing the same,
and more particularly, to high quality asphalt in which wax content
and ductility after a thin film oven test are improved by mixing a
typical vacuum residue with pitch that has a controlled chemical
composition and is obtained from a mixture comprising an
atmospheric residue and a petroleum distillate similar to the
atmospheric residue using a solvent deasphalting unit, and to a
method of preparing such high quality asphalt.
BACKGROUND ART
[0002] According to a conventional method of preparing asphalt
using a vacuum distillation unit as shown in FIG. 1, an atmospheric
residue produced using a crude distillation unit is subjected to a
vacuum distillation process to separate a vacuum residue having
controlled penetration, which is then directly produced into
asphalt.
[0003] The asphalt thus produced is used as material for paving
roads. As such, important properties of the asphalt, such as
penetration, penetration index, softening point, viscosity, wax
content, and ductility after a thin film oven test, should be
considered. Among these properties, penetration, which is a measure
of the hardness of asphalt, should be most fundamentally satisfied
in order to use asphalt as material for paving roads. Further, upon
evaluation of the quality of asphalt, the wax content and ductility
after a thin film oven test are mainly considered. As such, as the
wax content decreases and the ductility after the thin film oven
test increases, the quality of the asphalt is regarded as
improved.
[0004] In the case where a vacuum residue is directly made into
asphalt, a crude oil group suitable for the production of asphalt
is selectively combined and is then supplied into a crude
distillation unit, after which the separation temperature of the
vacuum residue is controlled using a vacuum distillation unit to
achieve desired penetration. Further, the other main properties may
have dependency on the crude oil supplied into the crude
distillation unit. As such, in order to produce asphalt having low
wax content and high ductility after the thin film oven test, the
crude oil group to be treated in the crude distillation unit must
be chosen appropriately. However, because the price of the crude
oil is a significant portion of the operating expense of refining
plants, economic benefits may be undesirably negated.
[0005] In addition, direct production of the vacuum residue into
high quality asphalt suffers because a vacuum gas oil produced
along with the vacuum residue using the vacuum distillation unit is
used as a feedstock of high-value processes such as hydrocracking
and fluid catalytic cracking, undesirably causing low quality of
relatively expensive vacuum gas oil or low yield upon operation of
the vacuum distillation unit to ensure the quality of asphalt. In
this regard, US Publication No. 2004-163996 discloses a method of
preparing asphalt using a vacuum residue or an atmospheric residue
as a feedstock.
[0006] Meanwhile, in particular consideration of the chemical
structure of the vacuum residue used in the direct production into
asphalt, the chemical structure of the atmospheric residue and
vacuum residue is composed of a saturate, an aromatic, resin, and
asphaltene. As such, it is known that a low wax content is realized
when the amount of saturate is low and that high ductility after a
thin film oven test is achieved when the amounts of saturate and
asphaltene are low and the amounts of aromatic and resin are high.
Upon vacuum distillation, since the vacuum gas oil and the vacuum
residue are separated from each other due to the separation
temperatures thereof, it is difficult to selectively increase the
amounts of aromatic and resin in the vacuum residue from the point
of view of the chemical structure in order to improve the wax
content and ductility after a thin film oven test. Moreover, the
chemical structure of the vacuum residue cannot but depend on the
crude oil.
DISCLOSURE OF INVENTION
Technical Problem
[0007] Leading to the present invention, intensive and thorough
research on high quality asphalt and preparation methods thereof,
carried out by the present inventors aiming to avoid the problems
encountered upon direct production of a vacuum residue into high
quality asphalt as mentioned above, resulted in the finding that a
solvent deasphalting process is used to produce pitch having a
controlled chemical composition, which is then mixed with a typical
vacuum residue and a similar light petroleum distillate, thus
producing high quality asphalt having superior wax content and
ductility after a thin film oven test.
[0008] As object of the present invention is to provide high
quality asphalt having superior wax content and ductility after a
thin film oven test.
[0009] Another object of the present invention is to provide a
method of preparing such high quality aspahlt.
Technical Solution
[0010] In order to accomplish the above objects, the present
invention provides high quality asphalt, which contains pitch
obtained by subjecting a mixture comprising a first vacuum residue
and a first petroleum distillate to solvent deasphalting.
[0011] In addition, the present invention provides a method of
preparing high quality asphalt, comprising conducting crude
distillation and vacuum distillation to produce a vacuum residue
for use in preparation of the asphalt, the method using pitch
obtained by subjecting a mixture of the vacuum residue, produced
through the vacuum distillation, and a first petroleum distillate,
which is lighter than the vacuum residue and has high amounts of
aromatic and resin, to solvent deasphalting.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The above and other objects, features and advantages of the
present invention will be more clearly understood from the
following detailed description taken in conjunction with the
accompanying drawings, in which:
[0013] FIG. 1 is a schematic view showing a conventional process of
preparing straight-run asphalt from a vacuum residue produced using
a vacuum distillation unit; and
[0014] FIG. 2 is a schematic view showing a process of preparing
high quality asphalt using a mixture of pitch, resulting from
solvent deasphalting, and a light distillate, according to the
present invention.
BEST MODE FOR CARRYING OUT THE INVENTION
[0015] Hereinafter, a detailed description will be given of the
present invention.
[0016] According to the conventional method of producing asphalt
described above, asphalt is directly produced from a vacuum gas oil
(VGO) and a vacuum residue (VR) produced using a vacuum
distillation unit (VDU) after subjecting an atmospheric residue
(AR) produced using a crude distillation unit (CDU) to vacuum
distillation. With reference to FIG. 1, the vacuum gas oil is
subjected to hydrocracking and fluid catalytic cracking and thus
refined into kerosene and gas oil, and gasoline, and the vacuum
residue is directly produced into asphalt.
[0017] However, asphalt according to the present invention contains
pitch which is obtained by mixing a first petroleum distillate
including the atmospheric reside produced using the crude
distillation unit with a first vacuum residue produced using the
vacuum distillation unit and then subjecting the mixture to solvent
deasphalting (SDA). Preferably, in order to control the
penetration, the pitch is mixed with a second vacuum residue and/or
a second petroleum distillate, thus obtaining asphalt. The asphalt
thus obtained has excellent wax content and ductility after a thin
film oven test.
[0018] FIG. 2 illustrates a process of preparing high quality
asphalt of the present invention. As shown in FIG. 2, the first
vacuum residue produced using the vacuum distillation unit is
appropriately mixed with the first petroleum distillate including
the atmospheric residue, after which the mixture is subjected to
solvent deasphalting, leading to deasphalted oil and pitch. The
deasphated oil is refined through hydrocracking and fluid catalytic
cracking, and the pitch is mixed with the second vacuum reside and
the second petroleum distillate to control the penetration thereof,
therefore preparing the asphalt of the present invention.
[0019] The mixing ratio of the first vacuum residue to the first
petroleum distillate is preferably 10.about.90 wt %. If the ratio
is less than 10 wt %, the effect of aromatic and resin contained in
the first petroleum distillate is low. On the other hand, if the
ratio exceeds 90 wt %, the amount of light oil is increased in the
pitch upon deasphalting and thus the quality of the asphalt is
worsened.
[0020] In the present invention, the petroleum distillate, which
may be mixed with the vacuum residue as a feedstock of a solvent
deasphalting process and a final mixing process, includes a heart
cut vacuum gas oil (HCVGO) resulting from vacuum distillation
and/or a slurry oil (SLO) resulting from fluid catalytic cracking,
in addition to the above atmospheric residue.
[0021] According to the present invention, the solvent deasphalting
process should be conducted such that the penetration of the pitch
resulting from solvent deasphalting is similar to (almost the same
as) or slightly lower than that of the vacuum residue to make the
pitch itself, or the mixture of the pitch and the vacuum residue
and/or petroleum distillate, into asphalt. In the case where the
penetration of the mixed asphalt is lower than the standard, it may
be controlled by further adding a distillate lighter than the
vacuum residue, such as an atmospheric residue, a heart cut vacuum
gas oil, and/or a slurry oil.
[0022] As the solvent used in the solvent deasphalting process, a
C3.about.C6 n-paraffin or isoparaffin solvent is mainly used.
Further, in order to control the penetration of the pitch, the use
of C3.about.C4 paraffin solvents or mixtures thereof is preferable.
In addition, the yield of the pitch, which varies with the ratio of
the atmospheric residue and the vacuum residue as the feedstock and
the operation conditions, typically falls in the range of about
10.about.90 vol %. When the yield of the pitch is high, soft
semi-finished products having high pitch penetration are obtained,
and the properties of the deasphalted oil are improved. When the
number of carbons of the solvent is low and the operating
temperature of the solvent deasphalting process is high, the yield
of the pitch is increased and thus the absolute amounts of aromatic
and resin are high. However, if the yield of the pitch is too high,
the standard for the penetration of asphalt products is difficult
to satisfy. In addition, a light distillate is present in a large
amount, and thus, ductility after the thin film oven test may be
deteriorated due to the promotion of oxidation upon the measurement
of ductility after the thin film oven test. Consequently, it is
important to appropriately control the yield of the pitch depending
on the properties of the feedstock of the solvent deasphalting
process.
[0023] In the present invention, the solvent deasphalting process
is preferably conducted at a pitch extraction temperature of
43.about.93.degree. C. in the presence of n-propane or
115.about.152.degree. C. in the presence of n-butane/iso-butane at
a pitch extraction pressure of 30.about.46 kg/cm.sup.2 g, in the
interest of improving ductility after the thin film oven test and
decreasing wax content.
[0024] Table 1 below shows the properties of the atmospheric
residue (AR) and vacuum residue (VR) as the feedstock and of the
deasphalted oil (DAO) and pitch produced from the above residue
mixture through the solvent deasphalting process. As is apparent
from Table 1, since the pitch has a lower amount of saturate than
that of the vacuum residue, it advantageously has a low wax
component. Further, the amounts of aromatic and resin are high,
realizing excellent ductility after a thin film oven test. This is
because the solvent used in solvent deasphalting is paraffin-based,
and thus, the saturate having high chemical affinity is somewhat
separated via the deasphalted oil, and the aromatic and resin
components having relatively lower affinity are not dissolved in
the solvent and are transferred to the pitch.
[0025] Thus, according to the present invention, not only the
atmospheric residue but also other petroleum distillates containing
high amounts of aromatic and resin are used as the feedstock along
with the vacuum residue, such that the saturate is removed in the
form of deasphalted oil, and the aromatic and resin are transferred
to the pitch, resulting in a distillate that is advantageous in
terms of wax content and ductility after a thin film oven test,
among the properties of asphalt.
TABLE-US-00001 TABLE 1 Properties of AR, VR, DAO and Pitch in
Solvent Deasphalting AR VR DAO Pitch Nitrogen, wt % 0.27 0.42 0.06
0.52 Sulfur, wt % 3.21 4.87 2.20 4.99 Nickel/Vanadium, 24.3/71
46.8/135.8 Trace/Trace 45.2/136.9 wppm Distillation, D2887 IBP 297
454 266 5% 365 514 339 30% 463 597 438 50% 535 647 488 70% 623 699
539 90% 604 95% 633 FBP 750+ 750+ 699 Recovered, % 91.7 83.0 100.0
Specific Gravity, 15/4 0.9757 1.0293 0.9177 1.0514 Conradson Carbon
10.73 23.34 0.99 25.68 Residue, wt % Chemical Composition Saturate
4.5 0.7 Aromatic 61.8 66.4 Resin 13.7 15.2 Asphaltene 20.0 17.7
MODE FOR THE INVENTION
[0026] A better understanding of the present invention may be
obtained in light of the following examples which are set forth to
illustrate, but are not to be construed to limit the present
invention.
Example 1
[0027] A feedstock comprising the atmospheric residue (AR) and the
vacuum residue (VR) having the properties shown in Table 1, mixed
at a volume ratio of 18:11, was subjected to solvent deasphalting
under the conditions shown in Table 2 below, thus producing
deasphalted oil and pitch. The results are shown in Table 3 below.
In order to control the penetration of the pitch thus obtained, a
heart cut vacuum residue was further added, leading to asphalt. The
properties of the asphalt thus obtained are shown in Table 4
below.
[0028] As is apparent from Table 4, in the case where the asphalt
was prepared using the pitch, it had higher amounts of aromatic and
resin and a lower amount of saturate than those of conventional
asphalt obtained from the vacuum residue produced using a vacuum
distillation unit, and thus high quality asphalt having low wax
content and high ductility after a thin film oven test could be
produced. Since the penetration of the asphalt was lower by about 6
than that of the vacuum residue, the asphalt comprising the pitch
had much higher ductility after a thin film oven test upon
correction of the penetration.
TABLE-US-00002 TABLE 2 Conditions of Solvent Deasphalting: 61%
Pitch Feed AR/VR (18/11 vol.) Solvent Propane Pitch Yield, wt % 61
Pressure, kg/cm.sup.2g 45.7 Temp. of Asphaltene Separator, .degree.
C. 83
TABLE-US-00003 TABLE 3 Feed of Solvent Deasphalting and Properties
of Product: 61% Pitch Feed DAO Pitch Specific Gravity, 15/4 0.9888
0.9177 1.0514 API Gravity 11.60 22.69 3.08 Nitrogen, wppm 0.34 0.06
0.52 Sulfur, wt % 3.84 2.20 4.99 CCR, wt % 15.86 0.99 25.68
Nickel/Vanadium, wppm 33.5/93.2 Trace/Trace 45.2/136.9 D2887,
.degree. C. IBP 291 266 5% 376 339 30% 512 438 50% 588 488 70% 660
539 90% 604 95% 633 FBP 750+ 699 Recovered, % 88.7 100.0
TABLE-US-00004 TABLE 4 Properties of VR and Pitch-Mixed Asphalt:
61% Pitch Conditions for High Pitch-Mixed Quality VR (Asphalt)
Asphalt Asphalt Mixing Ratio, vol. % VR 100 Pitch 82.3 HCVGO 17.7
Penetration at 25.degree. C., 0.1 mm 70 64 60~80 Softening Point,
.degree. C. 48.2 48.6 Min 47 Viscosity at 60.degree. C., Pa s 213
221 Min 180 Wax, wt % 1.87 1.49 Max 1.8 Ductility at 15.degree. C.,
cm 63 105 Min 100 Chemical Composition Saturate 4.5 2.3 Aromatic
61.8 66.9 Resin 13.7 14.1 Asphaltene 20.0 16.8
Example 2
[0029] A feedstock comprising the atmospheric residue and the
vacuum residue having the properties shown in Table 1, mixed at a
volume ratio of 18:11, was subjected to solvent deasphalting under
the conditions shown in Table 5 below, thus obtaining deasphalted
oil and pitch. The results are given in Table 6 below. The pitch
thus obtained was mixed with the vacuum residue and then with the
heart cut vacuum residue to control the penetration thereof,
leading to asphalt. The properties of the asphalt thus obtained are
shown in Table 7 below.
[0030] As is apparent from Table 7, the asphalt prepared using the
pitch was confirmed to have ductility after a thin film oven test
that was superior to that of asphalt produced from the vacuum
residue under the same penetration conditions.
TABLE-US-00005 TABLE 5 Conditions of Solvent Deasphalting: 70%
Pitch Feed AR/VR (18/11 vol.) Solvent Propane Pitch Yield, wt % 70
Pressure, kg/cm.sup.2g 45.7 Temp. of Asphaltene Separator, .degree.
C. 88
TABLE-US-00006 TABLE 6 Feed of Solvent Deasphalting and Properties
of Product: 70% Pitch Feed DAO Pitch Specific Gravity, 15/4 0.9888
0.9089 1.0385 API Gravity 11.60 24.18 4.75 Nitrogen, wppm 0.34 0.07
0.48 Sulfur, wt % 3.84 2.03 4.70 CCR, wt % 15.86 0.29 23.13
Nickel/Vanadium, wppm 33.5/93.2 Trace/Trace 40.5/129.4 D2887,
.degree. C. IBP 291 259 5% 376 332 30% 512 428 50% 588 475 70% 660
523 90% 591 95% 623 FBP 750+ 699 Recovered, % 88.7 99.5
TABLE-US-00007 TABLE 7 Properties of VR and Pitch-Mixed Asphalt:
70% Pitch Conditions for High Pitch-Mixed Quality VR (Asphalt)
Asphalt Asphalt Mixing Ratio, vol. % VR 100 30.0 Pitch 65.5 HCVGO
4.5 Penetration at 25.degree. C., 0.1 mm 70 70 60~80 Softening
Point, .degree. C. 48.2 48.0 Min 47 Viscosity at 60.degree. C., Pa
s 213 194 Min 180 Wax, wt % 1.87 1.49 Max 1.8 Ductility at
15.degree. C., cm 63 145+ Min 100 Chemical composition Saturate 4.5
2.4 Aromatic 61.8 62.6 Resin 13.7 18.5 Asphaltene 20.0 16.5
INDUSTRIAL APPLICABILITY
[0031] As described hereinbefore, the present invention provides
high quality asphalt containing pitch and a method of preparing the
same. According to the present invention, the operation conditions
of a solvent deasphalting process are appropriately controlled,
such that aromatic and resin components contained in an atmospheric
residue and a vacuum residue can be distributed to the pitch, and
as well, a saturate can be removed. Thus, compared to conventional
methods of preparing asphalt using only the vacuum residue, the wax
content and ductility after a thin film oven test can be further
improved.
[0032] Although the preferred embodiments of the present invention
have been disclosed for illustrative purposes, those skilled in the
art will appreciate that various modifications, additions and
substitutions are possible, without departing from the scope and
spirit of the invention as disclosed in the accompanying
claims.
* * * * *