U.S. patent application number 13/988305 was filed with the patent office on 2013-10-17 for process for desulfurization of diesel with reduced hydrogen consumption.
This patent application is currently assigned to INDIAN OIL CORPORATION LIMITED. The applicant listed for this patent is Anand Kumar, Brijesh Kumar, Sarvesh Kumar, Ravinder Kumar Malhotra, Santanam Rajagopal, Alok Sharma. Invention is credited to Anand Kumar, Brijesh Kumar, Sarvesh Kumar, Ravinder Kumar Malhotra, Santanam Rajagopal, Alok Sharma.
Application Number | 20130270155 13/988305 |
Document ID | / |
Family ID | 45470634 |
Filed Date | 2013-10-17 |
United States Patent
Application |
20130270155 |
Kind Code |
A1 |
Kumar; Sarvesh ; et
al. |
October 17, 2013 |
PROCESS FOR DESULFURIZATION OF DIESEL WITH REDUCED HYDROGEN
CONSUMPTION
Abstract
The present invention relates to a novel process for
desulfurization of diesel with reduced hydrogen consumption. More
particularly the subject invention pertains to an integrated
process comprising diesel hydro de-sulfurisation (DHDS) or diesel
hydrotreatment (DHDT) with reduced severity to desulfurize high
sulfur (1.0-2.0 wt %) diesel stream to a much lower level of sulfur
content of 350-500 ppm in the depleted diesel stream, followed by a
novel adsorption procedure for effecting deep desulfurization to
reduce overall sulfur content to less than 10 ppm with reduced
hydrogen consumption, as compared to high severity DHDS or DHDT
procedures of the prior art.
Inventors: |
Kumar; Sarvesh; (Faridabad,
IN) ; Sharma; Alok; (Faridabad, IN) ; Kumar;
Brijesh; (Faridabad, IN) ; Rajagopal; Santanam;
(Faridabad, IN) ; Malhotra; Ravinder Kumar;
(Faridabad, IN) ; Kumar; Anand; (Faridabad,
IN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Kumar; Sarvesh
Sharma; Alok
Kumar; Brijesh
Rajagopal; Santanam
Malhotra; Ravinder Kumar
Kumar; Anand |
Faridabad
Faridabad
Faridabad
Faridabad
Faridabad
Faridabad |
|
IN
IN
IN
IN
IN
IN |
|
|
Assignee: |
INDIAN OIL CORPORATION
LIMITED
Kolkata, West Bengal
IN
|
Family ID: |
45470634 |
Appl. No.: |
13/988305 |
Filed: |
November 16, 2011 |
PCT Filed: |
November 16, 2011 |
PCT NO: |
PCT/IN2011/000795 |
371 Date: |
May 17, 2013 |
Current U.S.
Class: |
208/212 |
Current CPC
Class: |
C10G 2300/4018 20130101;
C10G 2300/1055 20130101; C10G 2300/202 20130101; C10G 67/06
20130101; C10G 2400/04 20130101; C10G 25/00 20130101 |
Class at
Publication: |
208/212 |
International
Class: |
C10G 67/06 20060101
C10G067/06 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 19, 2010 |
IN |
1309/KOL/2010 |
Claims
1. A process for desulfurization of diesel with reduced hydrogen
consumption comprising the steps of: hydrotreating high
sulfur-containing diesel stream (1.0-2.0% by wt. of 5) over a NiMo
catalyst to reduce sulfur-content to a level of 350-500 ppm and
subjecting the treated diesel stream to an adsorption procedure to
bring down sulfur content to less than 10 ppm.
2. The process as claimed in claim 1, wherein treated diesel
containing about 350 ppm of refractory sulfur is split into two
cuts, such as (i) with IBP-140-150.degree. C.-280/300.degree. C.
containing less than 10 ppm sulfur, and (ii) with
FBP-280/300.degree. C. containing about 500-600 ppm of refractory
sulfur, wherein the cut containing less than 10 ppm sulfur may be
blended into diesel stream without any further treatment.
3. The process as claimed in claim 2, wherein the cut with FBP
280/300.degree. C. containing about 500-600 ppm of refractory
sulfur is desulfurized by the adsorption procedure.
4. The process as claimed in claim 1, wherein the process reduces
hydrogen consumption by 20% to 40%.
5. A process for desulfurization of diesel with reduced hydrogen
consumption comprising the steps of: hydrodesulphurizing high
sulfur-containing diesel stream (1.0-2.0% by wt. of 5) over a CoMo
catalyst to reduce sulfur-content to a level of 350-500 ppm and
subjecting the desulphurized diesel stream to an adsorption
procedure to bring down sulfur content to less than 10 ppm.
6. The process as claimed in claim 5, wherein desulphurized diesel
containing about 350 ppm of refractory sulfur is split into two
cuts, such as (i) with IBP-140-150.degree. C.-280/300.degree. C.
containing less than 10 ppm sulfur, and (ii) with
FBP-280/300.degree. C. containing about 500-600 ppm of refractory
sulfur, wherein the cut containing less than 10 ppm sulfur may be
blended into diesel stream without any further treatment.
7. The process as claimed in claim 6, wherein the cut with FBP
280/300.degree. C. containing about 500-600 ppm of refractory
sulfur is desulfurized by the adsorption procedure.
8. The process as claimed in claim 5, wherein the process reduces
hydrogen consumption by 20% to 40%.
9. The adsorption process as claimed in claim 1, further comprising
the following steps: operating two fixed bed reactors in swing mode
of adsorption and regeneration, and contacting the cut having FBP
280/300.degree. C. with the adsorbent along with hydrogen in down
or up-flow mode at a temperature of 350-400.degree. C., pressure of
15-30 bar, hydrogen to hydrocarbon ratio of 100-400
Nm.sup.3/m.sup.3, and liquid hourly space velocity of 0.5-2.0
h.sup.-1, depending on the sulfur content of the cut.
10. The process as claimed in claim 9, wherein the sulfur compounds
are chemically adsorbed on the adsorbent followed by cleavage of
sulfur from the sulfur compound and hydrocarbon molecules of the
sulfur compound are released back into the hydrocarbon stream.
11. The process as claimed in claim 9, wherein the adsorbent is
regenerated by controlled oxidation of the adsorbed carbon and
sulfur with lean air at a temperature ranging between 350.degree.
and 500.degree. C. and activation with hydrogen, wherein the
process is carried out in situ.
12. (canceled)
13. The process as claimed in claim 2, wherein the process reduces
hydrogen consumption by 20% to 40%.
14. The process as claimed in claim 3, wherein the process reduces
hydrogen consumption by 20% to 40%.
15. (canceled)
16. (canceled)
17. The process as claimed in claim 6, wherein the process reduces
hydrogen consumption by 20% to 40%.
18. The process as claimed in claim 7, wherein the process reduces
hydrogen consumption by 20% to 40%.
19. (canceled)
20. The adsorption process as claimed in claim 5, further
comprising the following steps: operating two fixed bed reactors in
swing mode of adsorption and regeneration, and contacting the cut
having FBP 280/300.degree. C. with the adsorbent along with
hydrogen in down or up-flow mode at a temperature of
350-400.degree. C., pressure of 15-30 bar, hydrogen to hydrocarbon
ratio of 100-400 Nm.sup.3/m.sup.3, and liquid hourly space velocity
of 0.5-2.0 h.sup.-1, depending on the sulfur content of the
cut.
21. The process as claimed in claim 20, wherein the sulfur
compounds are chemically adsorbed on the adsorbent followed by
cleavage of sulfur from the sulfur compound and hydrocarbon
molecules of the sulfur compound are released back into the
hydrocarbon stream.
22. The process as claimed in claim 20, wherein the adsorbent is
regenerated by controlled oxidation of the adsorbed carbon and
sulfur with lean air at a temperature ranging between 350.degree.
and 500.degree. C. and activation with hydrogen, wherein the
process is carried out in situ.
23. The process as claimed in claim 10, wherein the adsorbent is
regenerated by controlled oxidation of the adsorbed carbon and
sulfur with lean air at a temperature ranging between 350.degree.
and 500.degree. C. and activation with hydrogen, wherein the
process is carried out in situ.
24. The process as claimed in claim 21, wherein the adsorbent is
regenerated by controlled oxidation of the adsorbed carbon and
sulfur with lean air at a temperature ranging between 350.degree.
and 500.degree. C. and activation with hydrogen, wherein the
process is carried out in situ.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to desulfurization of diesel
and in particular to a novel process for deep desulfurization of
diesel with reduced hydrogen consumption. More particularly the
subject invention pertains to an integrated process comprising
diesel hydro de-sulfurisation (DHDS) or diesel hydrotreatment
(DHDT) with reduced severity, to desulfurize high sulfur-containing
(1-2%) diesel stream to a much lower level of sulfur content of
350-500 ppm in the treated diesel stream, followed by a novel
adsorption procedure for effecting deep desulfurization to reduce
overall sulfur content to less than 10 ppm with reduced hydrogen
consumption, as compared to high severity DHDS or DHDT procedures
followed in the prior art.
BACKGROUND OF THE INVENTION AND PRIOR ART
[0002] With increasing concern for environmental pollution,
regulatory norms are becoming increasingly stricter, forcing
refiners to search for novel and economically viable routes to
produce cleaner, eco-friendly fuels. The refining procedures
adopted so far invariably use severe/drastic operating conditions
involving high degree of hydrogen consumption and expensive
catalyst systems.
[0003] The residual sulfur below 500 ppm in diesel is mostly
refractory sulfur. Removal of the refractory sulfur of the diesel
through conventional hydrotreating requires severe operating
conditions like higher pressure, lower `Liquid Hourly Space
Velocity (LHSV)`, higher consumption of hydrogen, and use of highly
active and expensive catalyst systems.
[0004] The present invention provides a novel process to utilize a
reactive adsorbent for reducing refractory sulfur present in diesel
from 350-500 ppm to less than 10 ppm. The process developed in the
present invention can be utilized in the downstream of existing
DHDS/DHDT units. In the process, the hydrogen consumption is
significantly low, since it is consumed only for saturation of
olefinic bond generated by cleavage of the sulfur from the sulfur
compounds. The combination will result in reduced hydrogen
consumption at refineries.
[0005] The DHDS procedure employs catalytic hydrogenation to
upgrade the quality of diesel so as to conform to the environmental
norms by mainly removing sulfur and nitrogen. In addition, this
procedure brings about saturation of olefins and aromatic
compounds. Catalysts are formulated by combining varying amounts of
nickel or cobalt with molybdenum oxides on an aluminium base.
Important operating parameters of this procedure are, inter alia,
temperature, pressure, nature of catalyst, feed flow rate, feed
characteristics, etc. The catalysts used therein are meant for
carrying out reaction under less severe/drastic condition and at a
faster rate.
[0006] Removal of sulfur according to DHDS: Diesel contains sulfur
compounds such as mercaptans, sulphides, and/or disulphides which
are removed as H.sub.2S, as shown below:
Mercaptan.fwdarw.C--C--C--C--SH+H.sub.2=C--C--C--C--H+H.sub.2S
Sulphide.fwdarw.C--C--S--C--C+2H.sub.2=2C--C--H+H.sub.2S
Disulphide.fwdarw.C--C--S--S--C--C+3H.sub.2=2C--C--H+2H.sub.2S
[0007] US publication US20070261994A1 discloses a method for
producing a super-low sulfur gas oil blending component or a
super-low sulfur gas oil composition having a sulfur content of
less than 5 ppm, under relatively mild conditions, without greatly
increasing the hydrogen consumption and without remarkably
decreasing the aromatic content. However unlike the present
invention, the hydrogen consumption reduction is not clearly
specified. Moreover the composition of the catalyst used is
different. The present invention uses a process of splitting the
treated diesel between two fractions, which is not present in this
US publication.
[0008] U.S. Pat. No. 6,551,501B1 discloses a combined process for
improved hydrotreating of diesel fuels, in which the feed to be
hydrotreated is pretreated with a selective adsorbent prior to the
hydrotreating step to remove polar materials, especially nitrogen
containing compounds (N-compounds). In the present invention both
the hydrotreatment and adsorption process are used to reduce the
sulfur content in the fuel; however, the reduction of sulfur
content in two publications is different. In the US publication the
splitting of hydrocarbon and reduction of hydrogen consumption is
not mentioned.
[0009] PCT application WO2008122706A2 discloses an improved method
for deep desulphurisation of a gasoil comprising a catalytic
hyrodesulphurisation unit preceded by an absorption unit for
nitrogen compounds inhibiting the hydrodesulphurisation reaction.
However, the present invention uses either DHDT or DHDS process
followed by adsorption process for sulfur removal. The type of
catalyst, reduction of hydrogen consumption and reduction of
severity are not mentioned in the PCT publication.
[0010] US publication US2007023325A1, by the applicant of the
present invention has been mentioned separately in the following
description. It discloses the adsorbent that has been used in the
present invention too.
[0011] Hence there is a need to provide such a desulfurization
process that the sulfur content of the diesel can be brought down
to less than 10 ppm, while ensuring minimum consumption of
hydrogen. This invention therefore aims at overcoming the
difficulties or drawbacks of the procedures adopted in the prior
art for desulfurization of diesel.
SUMMARY OF THE INVENTION
[0012] The present invention provides an integrated process for
deep desulfurization of diesel. The integrated process comprises of
DHDS or DHDT process which operates with reduced severity and a
novel reactive adsorption process. While the DHDS or the DHDT
process reduces the sulfur content of the diesel being treated to
350-500 ppm, the adsorption process further reduces the sulfur
content to <10 ppm.
[0013] The present invention further provides splitting of treated
diesel containing about 350 ppm of refractory sulfur into two cuts
viz Initial boiling point (IBP) 140-150.degree. C.-280/300.degree.
C. and Final boiling point (FISP) 280/300.degree. C. The
280/300.degree. C.-IBP cut contains preferably less than 20 ppm
sulfur and more preferably less than 10 ppm sulfur which can be
blended into diesel stream without any further treatment and the
280/300.degree. C.-FBP cut containing about 500-600 ppm of
refractory sulfur can be desulfurized using novel adsorption
process capable of bringing down sulfur content of diesel to less
than 10 ppm.
[0014] Accordingly, the process in accordance with this invention
can be utilized in the downstream of existing DHDS/DHDT units. The
present invention shows consumption of hydrogen is significantly
low as compared to the prior art, because hydrogen is consumed only
for bringing about saturation of olefinic bonds generated by
cleavage of sulfur from the sulfur-containing compounds.
DETAILED DESCRIPTION OF THE INVENTION
[0015] The present invention discloses a novel process for
desulfurization of diesel with reduced hydrogen consumption, which
comprises hydrotreating high sulfur-containing diesel stream
(1.0-2.0% by wt. of 5) over a NiMo catalyst to reduce
sulfur-content to a level of 350-500 ppm, followed by subjecting
the treated diesel stream to a novel adsorption procedure to bring
down sulfur content to less than 10 ppm.
[0016] In this integrated process, high sulfur diesel stream
containing about 1.0-2.0 wt % sulfur can be hydrodesulfurized to a
level of 350-500 ppm sulfur product utilizing conventional DHDS or
DHDT process with subsequent processing by novel adsorption process
to reduce sulfur content below 10 ppm.
[0017] In one embodiment, the present invention, treated diesel
containing about 350 ppm of refractory sulfur is split into two
cuts viz. IBP(140-150.degree. C.)-280/300.degree. C. and FBP
280/300.degree. C. The280/300.degree. C.-IBP cut contains
preferably less than 20 ppm sulfur and preferably less than 10 ppm
sulfur. This cut can be blended into diesel stream without any
further treatment. The 280/300.degree. C.-FBP cut containing about
500-600 ppm of refractory sulfur can be desulfurized using novel
adsorption process.
[0018] The adsorption process comprises two numbers of fixed bed
reactors, which are being operated in swing mode of adsorption and
regeneration. During the adsorption process, 280/300.degree. C.-FBP
cut along with hydrogen is contacted with the adsorbent in down or
up flow mode at 350-400.degree. C., 15-30 bar, hydrogen to
hydrocarbon ratio of 100-400 Nm.sup.3/m.sup.3, liquid hourly space
velocity of 0.5-2.0 h.sup.-1 depending on the sulfur contents of
feed. During the adsorption process, the sulfur compounds are
chemically adsorbed on the adsorbent followed by cleavage of the
sulfur atom form the sulfur compound. The hydrocarbon molecule of
the sulfur compound is released back into the hydrocarbon stream.
The presence of hydrogen during the adsorption also prevents
deactivation of adsorbent due to coking. The treated diesel
contains less than 10 ppm sulfur which can be blended with other
cut to produce diesel pool containing less than 10 ppm sulfur.
After reaching the breakthrough point, the adsorbent is regenerated
at 350-500.degree. C.
[0019] Regeneration of adsorbent is accomplished in situ by
controlled oxidation of the adsorbed carbon and sulfur with lean
air followed by activation with hydrogen. The cycle time will vary
from 4 to 10 days depending on feed sulfur and boiling range. The
adsorbent has higher strength and thermal stability compared to
hydrotreating catalyst. The regenerability study for the adsorbent
has been conducted in pilot plant for 6 months (25 cycles) and
there was no loss of activity and physical properties, hence the
life of the adsorbent is expected to be similar to that of
hydrotreating catalyst systems.
[0020] Adsorbent: The adsorbent used in the process is disclosed in
prior art (US 2007/0023325) which is comprised of a base component,
a reactive component, and booster. The base component of adsorbent
is a porous material, which provides extrudibility and strength.
Such materials include alumina, clay, magnesia, titania or a
mixture of two or more such materials. The reactive component of
the adsorbent is a spinel oxide and prepared through solid-state
reaction of the individual metal oxides. This component is
responsible for detaching the sulfur atom from the sulfur
compounds. The activity booster component of the adsorbent is a
bimetallic alloy generated in situ from mixed metal oxides.
[0021] The present invention also provides a process for
regeneration of adsorbent comprises the steps of controlled
oxidation of the adsorbed carbon and sulfur with lean air at a
temperature ranging between 350.degree. C. and 500.degree. C., and
activation with hydrogen wherein the process is carried out in
situ.
BRIEF DESCRIPTION OF THE INVENTION ACCOMPANYING DRAWINGS
[0022] The present invention will be further explained with the
help of the drawings accompanying this specification, in which
[0023] FIG. 1 shows a flow diagram of hydroprocessing micro reactor
unit (MRU);
[0024] FIG. 2 shows GC-SCD chromatograms of 350 and 10 ppm
sulfur-product diesel;
[0025] FIG. 3 depicts the integrated process scheme for deep
desulfurization of high sulfur diesel feedstock and
[0026] FIG. 4 gives a schematic representation of the novel
adsorption procedure.
[0027] The invention will be further defined by the examples given
hereafter by way of illustration and not by way of limitation.
EXAMPLES
Example-1
[0028] Diesel stream containing 1.53 wt % sulfur was
hydrodesulfurized using commercial DHDS and DHDT catalyst system in
a hydroprocessing micro-reactor unit (MRU). The process flow
diagram of MRU is shown in FIG. 1. The severity of operating
parameters was chosen to get 10-30 ppm sulfur product. The details
of feed/ product properties and operating conditions are given in
Table-1:
TABLE-US-00001 TABLE 1 Details of feed/product properties and
operating conditions 1. Operating Conditions DHDT DHDS LHSV,
h.sup.-1 0.6 0.6 Temperature, .degree. C. 370 370 H.sub.2/HC ratio,
Nm.sup.3/m.sup.3 400 400 Pressure, bar 100 50 2. Catalyst NiMo CoMo
3. Feed/product DHDT DHDS properties Feed Product Product a)
Density @ 0.8449 0.8107 0.8265 15.degree. C., g/cc b) Sulfur, ppm
15300 20 30 c) CI (D4737) 50.8 57.9 55.1 4. H.sub.2 Consumption,
1.3 1.0 wt % of feed
EXAMPLE-2
[0029] Diesel stream containing 1.53 wt % sulfur was
hydrodesulfurized using highly active commercial DHDS and DHDT
catalyst system in a hydroprocessing micro-reactor unit (MRU). The
severity of operating parameters was reduced to get 350 ppm sulfur
product. The details of feed/ product properties and operating
conditions are given in Table-2:
TABLE-US-00002 TABLE 2 Details of feed/product properties and
operating conditions (350 ppm sulfur product) 1. Operating
Conditions DHDT DHDS LHSV, h.sup.-1 1.0 1.0 Temperature, .degree.
C. 350 350 H2/HC, Nm.sup.3/m.sup.3 250 250 Pressure, bar 50 50 2.
Catalyst NiMo CoMo 3. Feed/product DHDT DHDS properties Feed
Product Product a) Density @ 15.degree. C., g/cc 0.8449 0.8279
0.8283 b) Sulfur, ppm 15300 350 350 c) CI (D4737) 50.8 54.5 54.2 4.
H2 Consumption, 0.7 0.7 wt % of feed
[0030] The 350 ppm sulfur product was subsequently treated by novel
adsorption process to reduce total sulfur content below 10 ppm. The
detailed GC-SCD analysis of 350 and 10 ppm sulfur product diesel is
given below in Table-3. The GC-SCD Chromatograms of 350 and 10 ppm
sulfur product diesel is given below in FIG. 2 of the drawings.
TABLE-US-00003 TABLE 3 GC-SCD of 350 and 10 ppm sulfur Product
Diesel Total `S` in ppm RT 350 ppm `S` <10 ppm `S S. No. `S`
Compound Minutes Product Product 1 C6BT-4 38.73 4 2 C7BT-1 41.15 5
3 4-MDBT 41.68 27 4 MDBT-1 42.19 5 5 MDBT-2 42.55 6 6 C7BT-2 42.85
8 7 C2DBT-1 44.13 8 8 4,6-DMDBT 44.44 35 2.0 9 C2DBT-2 44.99 32 10
C2DBT-3 45.66 24 11 C2DBT-4 46.05 17 12 C2DBT-5 46.44 3 13 C2DBT-6
46.67 17 0.7 14 C3DBT-1 47.37 24 15 C3DBT-2 47.90 12 16 C3DBT-3
48.27 16 0.6 17 C3DBT-4 48.67 26 0.3 18 C3DBT-5 49.08 7 19 C3DBT-6
49.26 3 20 C3DBT-7 49.52 9 21 C4DBT-1 49.78 7 22 C4DBT-2 50.27 11
23 C4DBT-3 50.67 10 0.4 24 C4DBT-4 51.20 16 25 C4DBT-5 51.90 3 26
C4DBT 52.17 9 27 C5DBT-1 52.52 5 28 C5DBT-2 52.83 3 Total 350 4
[0031] It may be observed from GC-SCD of 350 ppm residual sulfur
containing diesel, the most of the sulfur compound exist in the
boiling above 300.degree. C.
EXAMPLE-3
[0032] Since most of the sulfur compounds exist in the boiling
range above 300.degree. C. in 350-500 ppm hydrodesulfurized diesel
(example-2), the 350 ppm sulfur product diesel from DHDS or DHDT
was split into two cuts viz. IBP to 280.degree. C. and FBP to
280.degree. C. The 280.degree. C. IBP cut contains less than 10 ppm
sulfur. The 280.degree. C.-FBP cut containing 530 ppm of refractory
sulfur was desulfurized using novel adsorption process to reduce
sulfur below 10 ppm. The details of various cuts and final product
diesel are given below in Table-4.
TABLE-US-00004 TABLE 4 Details of various cuts and final product
diesel 280.degree. C. -FBP Final IBP-280.degree. 280.degree. C.
-FBP treated by Product Property C. (390.degree. C.) Adsorption
process Diesel Wt fraction 0.35 0.65 0.65 1.00 S, ppm 8 530 6 7
Density, g/cc 0.83 0.8450 0.8450 0.8397
[0033] The integrated process scheme for deep desulfurization of
high sulfur diesel feed stocks is given in FIG. 3.
[0034] In this process scheme shown in FIG. 3 of the drawings, the
liquid product from the separator of DHDS/DHDT is sent to splitter
where wild naphtha [150 (-).degree. C. cut] is separated from top
of the column, 150-280.degree. C. cut from the middle and
280(+).degree. C. cut from bottom is separated. Bottom or bottom
along with middle cut further deep desulfurized using novel
adsorption process to reduce total sulfur content below 10 ppm. The
Adsorption process scheme is given in FIG. 4 of the drawings.
[0035] In the Adsorption process cetane number of the product is
not improved. However, since cetane number specification is same
for Euro-III and Euro-IV diesel, the process is particularly
suitable as a finishing step for further treatment of Euro-III
diesel after DHDS/DHDT.
[0036] The existing DHDT unit can be operated at lesser severity,
just sufficient to meet the cetane requirement, and further sulfur
reduction can be achieved by employing the novel adsorption
process. This will result in substantial saving of precious
hydrogen. From the data (Table-5), it can be observed that by
combining novel adsorption process with DHDS or DHDT units saves
about 20 to 40% hydrogen consumption respectively.
TABLE-US-00005 TABLE 5 Saving of hydrogen by integration of
Adsorption process with DHDS or DHDT unit Hydrogen Consumption S.
No. Activity wt % of feed 1. From 1.53% sulfur feed 1.0 to 30 ppm
sulfur product by DHDS (CoMo) From 1.53% sulfur feed 0.70 to 350
ppm sulfur product by DHDS (CoMo) From 350 ppm sulfur 0.1 product
to <10 ppm sulfur product by Adsorption process Saving of
hydrogen as 0.20 per present invention DHDS vs. DHDS + Adsorption
process 2. From 1.53% sulfur feed 1.30 to 20 ppm sulfur product by
DHDT (NiMo) From 1.53% sulfur feed 0.70 to 350 ppm sulfur product
by DHDT (NiMo) From 350 sulfur 0.10 product to <10 sulfur
product by Adsorption process Saving of hydrogen as 0.50 per
present invention DHDT vs. DHDT + Adsorption process
Advantages of the Present Invention
[0037] i. The invention offers an integrated process comprising
DHDS or DHDT operating with reduced severity followed by novel
reactive adsorption process. [0038] ii. The deep desulfurization
procedure involving high sulfur-containing diesel stream
effectively brings down the sulfur content to less than 10 ppm.
[0039] iii. The invented process reduces hydrogen consumption by
20-40% as compared to only DHDS or DHDT procedure with high
severity. [0040] iv. The subject invention effectively reduces
severity of DHDS or DHDT procedure and brings down sulfur content
to 350-500 ppm level, with a further reduction to less than 10 ppm
by employing the novel reactive adsorption procedure.
[0041] Although, the preferred embodiment of the present invention
has 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 recited in the accompanying claims.
* * * * *