U.S. patent application number 13/983968 was filed with the patent office on 2013-11-28 for process for improving aromaticity of heavy aromatic hydrocarbons.
This patent application is currently assigned to RELIANCE INDUSTRIES LIMITED. The applicant listed for this patent is Harender Bisht, Asit Das, Manthan Malvankar, Sukumar Mandal, Mahesh Marve, Amit Parekh, Vinod Rayan, Suyog Salgarkar, Ashwani Yadav, Manoj Yadav. Invention is credited to Harender Bisht, Asit Das, Manthan Malvankar, Sukumar Mandal, Mahesh Marve, Amit Parekh, Vinod Rayan, Suyog Salgarkar, Ashwani Yadav, Manoj Yadav.
Application Number | 20130313159 13/983968 |
Document ID | / |
Family ID | 46798608 |
Filed Date | 2013-11-28 |
United States Patent
Application |
20130313159 |
Kind Code |
A1 |
Marve; Mahesh ; et
al. |
November 28, 2013 |
PROCESS FOR IMPROVING AROMATICITY OF HEAVY AROMATIC
HYDROCARBONS
Abstract
A process for producing paraffin extracted clarified slurry oil
(raffinate) with improved aromaticity from the feed stock such as
clarified slurry oil (CSO) is provided. The obtained paraffin
extracted clarified slurry oil with improved aromaticity is
suitable for a variety of industrial applications. For example, it
can be used as a valuable feedstock for producing carbon black.
Inventors: |
Marve; Mahesh; (Navi Mumbai,
IN) ; Salgarkar; Suyog; (Dist. Osmanabad, IN)
; Malvankar; Manthan; (Surendranagar, IN) ;
Parekh; Amit; (Surat,, IN) ; Rayan; Vinod;
(Tuticorin, IN) ; Yadav; Ashwani; (Panchkula,
IN) ; Bisht; Harender; (Dehradun, IN) ; Yadav;
Manoj; (Rewari, IN) ; Mandal; Sukumar;
(Faridabad, IN) ; Das; Asit; (Faridabad,
IN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Marve; Mahesh
Salgarkar; Suyog
Malvankar; Manthan
Parekh; Amit
Rayan; Vinod
Yadav; Ashwani
Bisht; Harender
Yadav; Manoj
Mandal; Sukumar
Das; Asit |
Navi Mumbai
Dist. Osmanabad
Surendranagar
Surat,
Tuticorin
Panchkula
Dehradun
Rewari
Faridabad
Faridabad |
|
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN |
|
|
Assignee: |
RELIANCE INDUSTRIES LIMITED
Mumbai, Maharashtra
IN
|
Family ID: |
46798608 |
Appl. No.: |
13/983968 |
Filed: |
February 10, 2012 |
PCT Filed: |
February 10, 2012 |
PCT NO: |
PCT/IN2012/000093 |
371 Date: |
August 6, 2013 |
Current U.S.
Class: |
208/14 ; 208/332;
208/337 |
Current CPC
Class: |
C10G 2400/30 20130101;
C10G 21/16 20130101; C10G 73/12 20130101; C10G 21/14 20130101; C10G
2300/44 20130101; C10G 73/10 20130101; C10G 2300/1096 20130101 |
Class at
Publication: |
208/14 ; 208/337;
208/332 |
International
Class: |
C10G 21/16 20060101
C10G021/16; C10G 21/14 20060101 C10G021/14 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 11, 2011 |
IN |
402/MUM/2011 |
Claims
1. A process for producing raffinate with improved aromaticity;
said process comprising the following steps: a. mixing raffinate
feedstock having a BMCI ranging between 110 and 130 with a solvent
in an apparatus to obtain an oil-solvent mixture; b. heating the
oil-solvent mixture at a temperature ranging between 50 and
200.degree. C. to obtain a heated oil-solvent mixture; c.
vigorously agitating the heated oil-solvent mixture for a time
period ranging between 0.5 and 2 hours to obtain an oil-solvent
dispersion; d. allowing the dispersion to separate into paraffin
rich phase and raffinate phase; e. separating the raffinate phase
from the paraffin rich phase to obtain raffinate with aromatics
content of at least 90 wt % and a BMCI of at least 132.
2. The process as claimed in claim 1, further comprises heating the
separated paraffin rich phase at a temperature ranging between 40
and 80.degree. C. to remove solvent.
3. The process as claimed in claim 1, wherein the solvent is at
least one selected from the group consisting of C.sub.2 to C.sub.7
hydrocarbons and C.sub.3 to C.sub.7 ketones.
4. The process as claimed in claim 1, wherein the solvent is at
least one selected from the group consisting of C.sub.2 to C.sub.7
alkanes, C.sub.2 to C.sub.7 alkenes and C.sub.3 to C.sub.7
ketones.
5. The process as claimed in claim 1, wherein the proportion of the
solvent to oil ranges between 4:1 and 10:1.
6. The process as claimed in claim 1, wherein the heating is
carried out at a pressure ranging between 10 and 50
kg/cm.sup.2.
7. The process as claimed in claim 1, wherein the agitation of
heated oil-solvent mixture is carried out at a temperature ranging
between 50 and 200.degree. C. and at a pressure ranging between 10
and 50 kg/cm.sup.2.
8. The process as claimed in claim 1, wherein the agitation of
heated oil-solvent mixture is carried out at a speed ranging
between 500 and 3000 rpm.
9. The process as claimed in claim 1, wherein the step c is carried
out in a static mixer.
10. Raffinate with aromatics content of at least 90 wt % and having
a BMCI of at least 132, obtained by the process as claimed in claim
1.
Description
FIELD OF THE DISCLOSURE
[0001] The present disclosure relates to a process for producing
raffinate with improved aromaticity.
DEFINITIONS OF TERMS USED IN THE SPECIFICATION
[0002] The term "fluid catalytic cracking (FCC)" used in the
specification means the conversion process used in petroleum
refineries to convert the high-boiling, high-molecular weight
hydrocarbon fractions of petroleum crude oils to more valuable
gasoline, olefinic gases and other products.
[0003] The term "aromaticity" used in the specification means
chemical property in which a conjugated ring of unsaturated bonds,
lone pairs, or empty orbitals exhibit a stabilization stronger than
would be expected by the stabilization of conjugation. alone.
[0004] The term "raffinate" as used in the specification means
paraffin extracted clarified slurry oil.
[0005] The acronym "BMCI" means Bureau of Mines Correlation
Index.
BACKGROUND
[0006] Carbon black feed stock (CBFS) is a heavy hydrocarbon mix
(C.sub.20 to C.sub.50) which is the key raw material in
manufacturing carbon black. Carbon black finds extensive use in the
rubber industry as a reinforcing agent in rubber products such as
tyres, tubes, conveyer belts, cables and other mechanical rubber
goods. CBFS is also used as heating fuel oil in several industrial
units. Carbon black is obtained by the partial combustion and
thermal decomposition of highly aromatic hydrocarbon oils under
controlled conditions. Some of the most important feedstocks used
for producing carbon black include: clarified slurry oil (CSO)
obtained from fluid catalytic cracking of gas oils, ethylene
cracker residue from naphtha steam cracking and coal tar oils.
[0007] The presence of paraffins in heavy aromatic hydrocarbon
fractions (boiling above 300.degree. C.) substantially reduces
their suitability for certain applications such as production of
carbon black, anode coke, needle coke, and asphaltene stabilization
in delayed coker feedstock. Therefore, lower the amount of
paraffins in the heavy aromatic hydrocarbon fractions higher is the
value of such feedstocks for the above mentioned applications.
Another important characteristic is the Bureau of Mines Correlation
Index (BMCI), wherein, carbon black feedstock must have a high BMCI
to be able to offer a high yield of carbon black; therefore, heavy
aromatic hydrocarbon feedstock used to obtain the CBFS should have
a high BMCI. The BMCI is indicative of the aromaticity in aromatic
hydrocarbons. Feedstocks having a high BMCI give a higher yield of
carbon black with minimum heat input hence reducing the cost of
manufacturing. Also, the feedstock for carbon black should have low
sulfur content, as sulfur adversely affects the product quality,
leads to lower yield and corrodes the equipment.
[0008] The BMCI value for CBFS should be more than 132; whereas,
BMCI value of CSO obtained at FCC plant is in the range of 110-130,
typically less than 126, depending on the conversion in the FCC
unit. Higher conversion leads to higher BMCI. Therefore, there is
felt a need to increase the BMCI value of CSO above 132 before CSO
can be used as a CBFS feedstock for manufacturing Carbon Black.
Further, there is also felt a need to reduce the paraffin content
of CSO to enhance the applicability of the feedstock.
[0009] In the past several processes have been worked to increase
the BMCI value of CSO, which include:
[0010] Vacuum distillation of CSO:
[0011] Vacuum distillation of CSO separates light cycle oil (LCO)
range components from CSO. Several modifications in the vacuum
distillation unit such as incorporation of a CSO flasher, although
helped in improving the flash point of CSO, no improvement in the
BMCI value was observed.
[0012] Extraction of CSO using Furfural or NMP as solvent:
[0013] Solvent extraction using NMP or Furfural was found to be
unsuitable for CSO having very high aromatic content as clear
separation of the raffinate and the extract was very difficult, due
to the high aromaticity.
[0014] Solvent de-asphalting:
[0015] The process involves removing asphaltic material from
clarified slurry oil (CSO) through the extractive or precipitant
action of solvents.
[0016] Some representative patent documents which disclose solvent
de-asphalting process are discussed herein below.
[0017] US2002005374 discloses a process for upgrading a
non-hydrotreated feedstream which comprises solvent deasphalting
the feedstream to obtain a first product stream comprising
deasphalted oil and a second product stream comprising an asphalt
product; slurry hydroprocessing the asphalt product to obtain a
hydroprocessed product; and separating an upgraded oil from the
hydroprocessed product and unconverted asphaltene bottoms.
[0018] US20090166253 disclose systems and methods for processing
one or more hydrocarbons for selectively separating to provide one
or more light deasphalted oils (DAO) which can be cracked to
provide hydrocarbon products. The method comprises: combining the
feedstock comprising heavy oils, light oils, and asphaltenes with
one or more solvents to provide a first mixture; separating the
asphaltenes from the first mixture to provide a second mixture
comprising solvent, heavy deasphalted oils, and light deasphalted
oils; selectively separating the heavy deasphalted oils from the
second mixture to provide a third mixture comprising the solvent
and light deasphalted oils; and selectively separating the solvent
from the third mixture to give light deasphalted oils.
[0019] US2010243518 discloses integrated slurry hydrocracking (SHC)
and solvent de-asphalting (SDA) methods for making slurry
hydrocracking (SHC) distillates. The method involves subjecting SHC
gas oil to the SDA process to obtain de-asphalted oil (DAO) and an
SDA pitch, wherein, at least a portion of the DAO is recycled to
the SHC reaction zone.
[0020] US20090166266 discloses a method for dewatering and
deasphalting a crude oil that comprises hydrocarbons, asphaltenes
and water with one or more solvents.
[0021] The feed as employed in the presently known deasphalting
processes is usually a vacuum residue or atmospheric residue or
crude oil with an asphaltene content in excess of 5 wt %. It is
known that the presently known deasphalting process cannot be
carried out if the asphaltene content in the input stream is lower
than 5 wt %.
[0022] Another shortcoming of the known deasphalting processes is
that the residue Fraction (asphalt) as resulting from these
processes is solid at room temperature and therefore it poses
significant difficulty in transportation.
[0023] Furthermore, for the presently known deasphalting processes
to be economical the minimum limit for the DAO yield is 40% and the
yields lower than this threshold render the process economically
un-feasible.
[0024] Still furthermore, the presently known deasphalting
processes are silent on further value addition in the properties of
the resultant deasphalted products such as improved aromaticity and
higher BMCI value.
[0025] Accordingly, there is felt a need for developing a new
process that extracts paraffinic material from CSO (clarified
slurry oil) leading to produce raffinate with improved aromaticity
and BMCI.
OBJECTS
[0026] Some of the objects of the present disclosure, which at
least one embodiment herein satisfies, are as follows:
[0027] An object of the present disclosure is to provide a paraffin
extraction process that is suitable for a feed with low asphaltene
content such as clarified slurry oil.
[0028] Another object of the present disclosure is to provide a
process for improving the aromaticity of heavy aromatic
hydrocarbons.
[0029] Still another object of the present disclosure is to provide
a process for improving the aromaticity of clarified slurry oil
(CSO).
[0030] Yet another object of the present disclosure is to provide a
process for reducing the paraffin content of clarified slurry
oil.
[0031] Still another object of the present disclosure is to provide
a process which gives clarified slurry oil having Bureau of Mines
Correlation Index (BMCI) greater than 132.
[0032] A further object of the present disclosure is to provide a
process for improving the aromaticity of clarified slurry oil,
which gives a useful by-product such as extracted paraffin rich
oil.
[0033] Other objects and advantages of the present disclosure will
be more apparent from the following description when read in
conjunction with the accompanying figures, which are not intended
to limit the scope of the present disclosure.
SUMMARY
[0034] In accordance with the present disclosure there is provided
a process for producing raffinate with improved aromaticity; said
process comprising the following steps: [0035] mixing CSOfeedstock
having a BMCI ranging between 110 and 130 with a solvent in an
apparatus to obtain an oil-solvent mixture; [0036] heating the
oil-solvent mixture at a temperature ranging between 50 and
200.degree. C. to obtain a heated oil-solvent mixture; [0037]
vigorously agitating the heated oil-solvent mixture for a time
period ranging between 0.5 and 2 hours to obtain an oil-solvent
dispersion; [0038] allowing the dispersion to separate into
paraffin rich phase and raffinate phase. [0039] separating the
raffinate phase from the paraffin rich phase to obtain raffinate
with aromatics content of at least 90 wt % and a BMCI of at least
132.
[0040] In accordance with another embodiment of the present
disclosure the process further comprises heating the separated
paraffin rich phase at a temperature ranging between 40 and
80.degree. C. to remove solvent for recycling.
[0041] Typically, the solvent is at least one selected from the
group consisting of C.sub.2 to C.sub.7 hydrocarbons and C.sub.3 to
C.sub.7 ketones.
[0042] In accordance with another embodiment of the present
disclosure the solvent is at least one selected from the group
consisting of C.sub.2 to C.sub.7 alkanes, C.sub.2 to C.sub.7
alkenes and C.sub.3 to C.sub.7 ketones.
[0043] Typically, the proportion of the solvent to oil ranges
between 4:1 and 10:1
[0044] Typically, the heating is carried out at a pressure ranging
between 10 and 50 kg/cm.sup.2.
[0045] Typically, the mixing of heated oil-solvent mixture is
carried out by using a static mixer or mechanical stirrer at a
temperature ranging between 50 to 200.degree. C. and at a pressure
ranging between 10 and 50 kg/cm.sup.2.
[0046] Typically, the agitation of heated oil-solvent mixture is
carried out at a speed ranging between 560 to 3000 rpm to ensure
proper mixing.
[0047] Typically, the pressure drops across static mixer is in the
range of 1 to 10 kg/cm2 (g) to ensure proper mixing.
[0048] In accordance with another aspect of the present disclosure
there is provided raffinate with aromatics content of at least 90
wt % and having a BMCI of at least 132, obtained by the process of
the present disclosure.
DETAILED DESCRIPTION
[0049] The embodiments herein and the various features and
advantageous details thereof are explained with reference to the
non-limiting embodiments in the following description. Descriptions
of well-known components and processing techniques are omitted so
as to not unnecessarily obscure the embodiments herein. The
examples used herein are intended merely to facilitate an
understanding of ways in which the embodiments herein may be
practiced and to further enable those of skill in the art to
practice the embodiments herein. Accordingly, the examples should
not be construed as limiting the scope of the embodiments
herein.
[0050] The description herein after, of the specific embodiments
will so fully reveal the general nature of the embodiments herein
that others can, by applying current knowledge, readily modify
and/or adapt for various applications such specific embodiments
without departing from the generic concept, and, therefore, such
adaptations and modifications should and are intended to be
comprehended within the meaning and range of equivalents of the
disclosed embodiments. It is to be understood that the phraseology
or terminology employed herein is for the purpose of description
and not of limitation. Therefore, while the embodiments herein have
been described in terms of preferred embodiments, those skilled in
the art will recognize that the embodiments herein can be practiced
with modification within the spirit and scope of the embodiments as
described herein.
[0051] The present disclosure envisages a novel process for
producing raffinate (paraffin extracted clarified slurry oil) with
improved aromaticity by extracting paraffin from feedstock such as
clarified slurry oil (CSO). Further, the present disclosure also
aims at reducing the paraffin content of clarified slurry oil. The
paraffin extracted clarified slurry oil (raffinate) so obtained has
a high Bureau of Mining Correlation (BMCI), i.e. at least 132,
which makes it suitable for applications like raw material for
carbon black production, anode coke production, needle coke
production, and as a diluent for improving asphaltene stability of
delayed coker feedstock. The process of the present disclosure also
provides an extract (paraffin rich oil) which comprises
approximately 50-90% of the total paraffin content of the clarified
slurry oil feedstock. This by-product can be used as a feed in
fluid catalytic cracking (FCC) process and hydrocracking process,
as a lube oil base stock and as a thermic fluid.
[0052] The process for preparing raffinate (paraffin extracted
clarified slurry oil) with improved aromaticity from clarified
slurry oil in accordance with the present disclosure is described
herein below.
[0053] In the first step, clarified slurry oil feedstock having a
BMCI of 110 to 130 is mixed with a solvent in an apparatus to
obtain an oil-solvent mixture. The solvent used is at least one
selected from the group consisting of C.sub.2 to C.sub.7
hydrocarbons and C.sub.3 to C.sub.7 ketones. In one of the
preferred embodiment the solvent used is a light hydrocarbon
selected from the group consisting of C.sub.2 to C.sub.7 alkanes
and C.sub.2 to C.sub.7 alkenes. Typically, the structure of the
hydrocarbon can be linear, branched (iso), and/or cyclic.
[0054] The clarified slurry oil is highly aromatic; thus, it is
easier to separate out the paraffins from the slurry oil on the
basis of its solubility in the light hydrocarbons, ketones or their
mixtures. Depending on the process operating conditions and/or the
final applicability of the raffinate from clarified slurry oil and
the by-product i.e., paraffinic rich oil a suitable solvent or a
mixture of solvents can be used in the process of the present
disclosure for improving the aromatic content and reducing the
paraffinic content. E.g. propylene or ethylene may be added to
improve the selectivity towards the by-product i.e. paraffinic rich
oil.
[0055] The solvent to oil ratio used is typically in the range of
4:1 to 10:1. The solubilization of the solvent in the slurry oil is
typically carried out continuously in vessel or on-line which is
maintained at a pressure in the range of 10-50 kg/cm.sup.2 to
obtain an oil-solvent mixture.
[0056] In the second step, the oil-solvent mixture is heated at a
temperature in the range of 50 to 200.degree. C. to obtain a heated
oil-solvent mixture. The process temperature can be varied
depending on type of the solvent and % of paraffinic oil lift
required. In the next step, the heated oil-solvent mixture is
agitated vigorously for 0.5 to 2 hours while maintaining the
temperature and pressure conditions in the autoclave.
Alternatively, mechanical devices like static mixer can be used to
ensure intimate mixing. The agitator speed is typically in the
range of 500 to 3000 rpm. The obtained oil-solvent dispersion is
allowed to cool and separate to obtain biphase mixture containing
extract (paraffin rich phase) and raffinate phase.
[0057] In the next step, the extract i.e, paraffin rich oil and the
raffinate phase comprising aromatic rich slurry oil are
separated.
[0058] The paraffin rich oil can be subsequently heated at a
temperature in the range of 40 to 80.degree. C. to remove solvent
which is recycled as a solvent. The paraffin rich oil thus obtained
comprises approximately 50 to 90 wt % of the total paraffins
content of the clarified slurry oil feedstock. The paraffin rich
oil thus obtained as a by-product of the process can be suitably
used as a feedstock for fluid catalytic cracking (FCC) with or
without hydrotreating to subsequently obtain FCC products; a
feedstock in hydrocracking process for obtaining high quality
diesel and other derivative products; as a lubricating oil base
stock; and as a thermic fluid for heat transfer applications. The
paraffin rich oil yield can be varied in the range of 15-30 wt % of
clarified slurry oil (CSO) feedstock by manipulating the operating
temperature between 50 and 85.degree. C. and varying solvent to oil
ratio.
[0059] The raffinate phase (fraction) of clarified slurry oil
obtained by the process of the present disclosure is characterized
by aromatics content of at least 90 wt %. i.e. the aromatic content
of the raffinate fraction of clarified slurry oil is at least 5-10
wt % more than the aromatic content of the clarified slurry oil
feedstock.
[0060] Further, the BMCI of the raffinate is found to be at least
132 which is higher than the BMCI of clarified slurry oil
feedstock.
[0061] When propane was used as a solvent, in the raffinate thus
obtained, it was observed that the aromatic content was increased
by 6 wt %, the API (American Petroleum Institute) gravity was
increased by 2 units, and the mean boiling temperature was
increased by 8.degree. C., in comparison with the clarified slurry
oil feedstock. Further, the BMCI, estimated by gravity and
distillation method, was increased from 127 to 134.
[0062] The raffinate thus obtained is a valuable feedstock for
processes including: feedstock for producing carbon black which is
extensively used in the tyre and ink industry; feedstock for
producing anode coke which is used in manufacturing electrodes in
aluminum industries; feedstock for producing needle coke which is
used in manufacturing electrodes for high temperature applications
in steel industries; and as a diluent for improving the asphaltene
stability of delayed coker feedstock, as higher aromaticity in
coker and visbreaker feed improves the asphaltene stability and
helps to reduce the coking rates in furnace tubes thus giving an
improved run length of coker.
[0063] Therefore, the process of the present disclosure, i.e.,
separation of paraffin rich oil and aromatic rich raffinate by the
solvent extraction of clarified shiny oil feedstock, improves the
economic benefits of both the products (raffinate) and the
by-product (paraffin rich oil), by making them more suitable for a
variety of industrial applications.
[0064] The disclosure will now be described with respect to the
following examples and illustrations which do not limit the scope
and ambit of the disclosure in anyway and only exemplify the
disclosure.
EXAMPLE
[0065] 55 gms of clarified slurry oil (CSO) feedstock was mixed
with propane, in a propane to oil ratio of 6:1, in an autoclave.
The oil-solvent mixture was heated to 85.degree. C. at a pressure
of 33 kg/cm.sup.2 and the resultant mixture was stirred for one
hour at 1000 rpm while maintaining the temperature and pressure
conditions. The stirring and heating was stopped and the resultant
dispersion was allowed to settle under gravity for one hour, thus
allowing the separation of a paraffin rich phase (extract) and a
aromatic rich phase (raffinate) which is a heavier fraction. The
paraffin rich phase (extract) was decanted out from the top and was
separately heated to 50.degree. C. to remove propane. The samples
of the paraffin rich phase (extract) were tested in Advanced
Cracking Evaluation (ACE) reactor for crack-ability. The aromatic
rich phase (raffinate) was subsequently obtained after decanting.
The extract and raffinate were analyzed for viscosity, density,
High Temperature Simulated Distillation and SARA (Saturates,
Asphaltenes, Resins and Aromatics) analysis. The SARA analysis was
done using TLC-FID analyzer. The properties of clarified slurry oil
feedstock, raffinate and extract are illustrated in TABLE 1.
TABLE-US-00001 TABLE 1 Properties of clarified slurry oil feedstock
(CSO), raffinate and extract Specification for use as carbon black
feedstock Units CSO Raffinate Extract CBFS Average Yield wt % 100
82 18 -- (for 3 consecu- tive runs) Specific gravity -- 1.0836 1.10
1.01 Maximum 1.10 at 15.degree. C. API gravity -- -0.917 -2.86 8.60
Maximum -2.9 BMCI (by -- 127 134 94.65 Minimum 132 gravity &
distillation method) Sulfur Content wt % 1.458 1.65 0.278 Maximum 3
Saturates wt % 11.65 4.94 31.93 -- Aromatics wt % 85.83 91.69 66.51
-- Asphaltenes wt % 0.47 0.78 0.16 Maximum 6 Catalyst wt % 12.52
15.25 0.07 -- Regeneration Reformers (CCR)
[0066] The data reported in the TABLE 1 is for samples having 18 wt
% paraffin rich oil (Extract) and 82% aromatic rich phase
(raffinate). The data presented is for a typical set of properties
and not to be considered as limiting in any way the process as
such.
[0067] The BMCI was calculated using the following equation:
BMCI=(48640/T)+(473.7*specific gravity)-456.8
[0068] where, T(.degree.
K)=273+(T.sub.10+T.sub.30+T.sub.50+T.sub.70+T.sub.90)/5
[0069] It was observed that the aromatic content of the raffinate
was 6 wt % higher than the clarified slurry oil (CSO) feedstock.
Further, the corresponding API gravity of raffinate was increased
by 2 units and the BMCI value calculated by gravity and
distillation method was increased from 127 to 134, in comparison
with the feedstock. A higher density and lower average boiling
point is desired for improving the BMCI. Still further, the propane
extraction process removed more than 50% of saturates from the
feedstock, as, in the raffinate obtained. The experiment was
carried out in a single-stage mixer settler lab autoclave unit. The
extract yield and its saturate content are expected to improve
further in a continuous multi-stage extraction process having
special internals for better mixing and settling. The extract
obtained by the extraction process of the present disclosure has
low Conradson Carbon Residue (CCR) and Asphaltenes content, which
makes the extract suitable as a FCC feed with or without
hydrotreating, as a hydrocracker feed, as lube oil base stock, and
as thermic fluid for heat transfer applications.
[0070] The clarified slurry oil feedstock (CSO), raffinate and
extract were analyzed in a gas chromatograph (High temperature
Simdist, D7169). The analysis is illustrated in TABLE 2.
TABLE-US-00002 TABLE 2 High temperature Simdist temperature
analysis of clarified slurry oil feedstock (CSO), raffinate and
extract Temperature (.degree. C.) Recovered Mass % CSO Raffinate
Extract Initial Boiling Point (IBP) 223 229 148.5 5 313.5 320 265
10 345 347 311.5 20 363.5 365.6 352.5 30 378 380.5 368.5 50 406 409
395 70 440 447 421.5 80 467 476 439.5 90 517 542 469.5 95 582.5
601.5 493.5 Final Boiling Point (FBP) 693 696 617.5 T = (T.sub.10 +
T.sub.30 + 417.2 425.1 393.2 T.sub.50 + T.sub.70 + T.sub.90)/5
[0071] Further, the crack-ability of extract was studied in an ACE
reactor; the data was generated at base conditions of 545.degree.
C. and compared with corresponding conversion selectivity plots of
hydrotreated vacuum gas oil (VGO) feedstock. The extract showed a
much lower conversion than hydrotreated (DDT) VGO, 40-45 wt %
vis-a-vis 70-80 wt %, at different catalyst to oil ratio. This is
consistent with higher aromatics content of extract and reflected
in lower UOP K. Higher aromatics also result in higher coke make.
Since, the CCR and Asphaltenes content of extract are within the
limits of hydrotreater feed requirement, it is possible to process
the extract in hydrotreater for aromatics saturation and UOP K
improvement. KBC VGO-HT Kinetic model estimates showed aromatics
saturation in extract from 65% to 50% by wt and UOPK factor
improvement from 10.4 to 10.7. Extract as such shows a conversion
of approximately 41 wt % (at 216.degree. C.) and approximately 66
wt % (at 370.degree. C.). Hydrotreating improves the conversion to
approximately 47 wt % (at 216.degree. C.) and approximately 77 wt %
(at 370.degree. C.). This shows substantial potential for upgrading
the extract through VGO-HT and FCC. TABLE 3 illustrates yields
estimates of products of extract and hydrotreated (HDT) extract in
FCC by KBC Simulation Kinetic model.
TABLE-US-00003 TABLE 3 Yield of products by cracking extract
obtained by process of the present disclosure in FCC Base &
100% Base & HDT 100% HDT Product Unit Base Extract Extract
Extract Extract Dry Gas wt % 5.01 4.98 4.96 3.13 1.72 Propylene wt
% 9.50 9.44 9.46 5.47 6.97 Total wt % 20.24 20.08 20.13 9.07 12.62
C.sub.3 + C.sub.4 Total Naphtha wt % 37.32 37.05 37.10 18.67 22.20
Light Cycle Oil wt % 15.11 15.24 15.19 24.21 20.41 Clarified Oil wt
% 7.50 7.89 7.85 34.15 30.68 Coke wt % 5.32 5.32 5.32 5.30 5.39
Conversion wt % 77.39 76.87 76.96 41.65 47.33 Total 100 100 100 100
100
Technical Advantages
[0072] A process for improving the aromaticity of heavy aromatic
hydrocarbons as described in the present disclosure has several
technical advantages including but not limited to the realization
of [0073] the aromatic content of clarified slurry oil feedstock
can be increased by 5-10 wt. %; [0074] the BMCI of paraffin
extracted clarified slurry oil (raffinate) is at least 132; [0075]
the paraffin content of raffinate is substantially reduced; [0076]
the API gravity of raffinate is increased; and [0077] the
applicability and thus the economic benefit of the raffinate and
extract are improved.
[0078] Throughout this specification the word "comprise", or
variations such as "comprises" or "comprising", will be understood
to imply the inclusion of a stated element, integer or step, or
group of elements, integers or steps, but not the exclusion of any
other element, integer or step, or group of elements, integers or
steps.
[0079] The use of the expression "at least" or "at least one"
suggests the use of one or more elements or ingredients or
quantities, as the use may be in the embodiment of the disclosure
to achieve one or more of the desired objects or results.
[0080] Any discussion of documents, acts, materials, devices,
articles or the like that has been included in this specification
is solely for the purpose of providing a context for the
disclosure. It is not to be taken as an admission that any or all
of these matters form part of the prior art base or were common
general knowledge in the field relevant to the disclosure as it
existed anywhere before the priority date of this application.
[0081] The numerical values mentioned for the various physical
parameters, dimensions or quantities are only approximations and it
is envisaged that the values higher/lower than the numerical values
assigned to the parameters, dimensions or quantities fall within
the scope of the disclosure, unless there is a statement in the
specification specific to the contrary.
* * * * *