FORM-2
THE PATENT ACT,1970
(39 OF 1970)
AND
THE PATENT RULES, 2003
(As Amended)
COMPLETE SPECIFICATION
(See section 10;rule 13)
" THE NOVEL PROCESS FOR RECLAMATION OF OIL IN WATER EMULSION COLLECTED FROM CRUDE OIL DE-SALTER
BRINE WATER "
NAYARA ENERGY LIMITED, a corporation organized and existing under the laws of India, of 39 KM Jamnagar-
Okha Highway, Vadinar, Dist Devbhoomi Dwarka, Gujarat, India.
The following specification particularly describes the invention and the manner in which it is to be performed:
2
Title of Invention: The novel process for reclamation of oil in water emulsion
collected from crude oil de-salter brine water
Field of the invention:
The present invention relates to crude oil refining process, more specifically to effluent
treatment process (ETP) where crude oil de-salter brine water received for processing,
further more specific to oil-in-water emulsion collected after ETP process from de-salter
brine water.
Background of the invention:
Crude oil is natural fossil fuel extracted from earth, sometime synthetic material also
mixed with it. After exploration and cleaning process, crude oil mainly consist of mixture
of hydrocarbon and trace quantity of water and sediments. The concentration of water
and sediments are vary based on types of crude oil, source of crude oil and cleaning
process employed after exploration. Presence of water and sediments has many
disadvantage in refining process.
To minimize fouling, corrosion and frequent breakdown, removal of water and sediments
is must before it entering into crude oil distillation (CDU) process. Most of refinery using
de-salting process to remove water with dissolved salt and sediments from crude oil just
before crude oil distillation process.
Crude oil is heated at around 145 ⁰C and 5 to 6% fresh de-saline water added to dilute
the existing water soluble salts, then after proper mixing it enter into de-salter vessel. In
de-salter, an oil–water mixture put into settling vessel, where water with dissolved salt &
sediments/ sludge particles get separated and settled at bottom portion of vessel called
brine water which drained from bottom valve. The de-salted crude oil from top layer of
vessel send to the distillation process. The electric current applied to promote phase
separation and settling effect.
During brine water & sediments / sludge draining process, small quantity of crude oil also
get carryover with brine water, which needs to be recollect to save the fuel as well as to
minimize losses.
3
The quantity of oil in brain water depends on the de-salter technology, type of crude oil
under process, condition of de-salter unit and standard operating procedure being
followed. The de-salter brine water test results indicate that, the oil quantity is in the
range of few ppm to 10% level.
For recollection of oil from de-salter brine water, it has to pass through many settling
stages with or without chemical, mechanical & heating treatments at ETP.
The collected oil-in-water emulsion after existing ETP treatment also called de-salter slop
oil or emulsion. The crude oil refinery, collecting de-salter slop oil emulsion form existing
ETP process is in the range of 0.2 to 1.0% of its crude oil throughput. The collected oilin-
water emulsion is in very tight form, hence further separation of water and sediments
not possible by existing normal effluent treatment process.
For example, 20 MMTPA crude oil refinery, generate approximately 1277000 M3 of brine
water per year and collect oil-in-water emulsion in the range of 40000 to 200000 MT/
Year.
The analysis data of de-salter slop oil emulsion indicate that, it mainly consist of 20 to 70
vol. % heavy hydrocarbons, 29 to 78 vol. % water and 1 to 10 vol % sediments which
are in very tight emulsion form, also there are presence of many undesirable metal
elements viz iron, sodium, calcium, magnesium, aluminium, silica, chloride, sulphate etc.
De-salter oil-in-water emulsion collected after treatment at ETP can be either reprocess
at refinery or can be disposed of according to legal compliance process. Reprocessing at
refinery is a cheap option than any other options. Hence de-salter oil-in-water emulsion
collected after treatment at ETP is being reprocessing with crude oil at Nayara Energy
since inception. The quantity of emulsion generated at ETP and reprocessed at CDU
during 2019 was approx. 154000 M3.
Due to huge quantity and worst quality of de-salter slop oil emulsion, crude oil refinery
facing many problems while reprocessing emulsion even at lower concentration (<1 % )
of crude throughput viz
1) The huge quantity of emulsion is reducing refining capacity and increasing
processing cost hence it has very big financial impact on GRM due to high reprocessing
cost (2 to 4 USD / barrel of emulsion), also consume extra energy at different stages,
require multiple storage, treatment and handling facilities ( tanks, chemicals, mechanical
4
and heating resources). It has adverse impact on environment as well as it increase
hazardous risk.
2) The worst quality of emulsion (high level of water and sediment in tight emulsion
form) is destabilize de-salter & CDU operation, generating more slop oil during de-salting
process and creating vicious cycle of emulsion.
3) Some time, oil-in-water emulsion generation is very high and it is difficult to
manage inventory, hence it become compulsion to reprocess within time frame even at
the cost of more CDU throughput loss.
4) It increase fouling, corrosion and frequent breakdown.
5) It also impacting on aviation turbine fuel (ATF) production with respect to
deteriorating of ATF colour.
There are many literature indicate the separation of water from crude oil, refinery slop
oil, oily sludge etc. by different technology viz settling, filtration, centrifuge, chemical
emulsification, microwave irradiation, ultrasonic irradiation etc.
The use of ultrasonic irradiation is known for breaking crude oil hydrocarbon / water
emulsion as described in U.S. patent 2257997, 3200567, 3594314 and
WO2004/033377A1 and GB 2274850. However none of these patent directly deals with
oil in water emulsion collected after treatment at ETP from de-salter brine water.
Therefore it would be great benefit to the refining world by providing a reclamation
process for emulsion collected after treatment at ETP from crude oil de-salter brine water,
which can reduce emulsion quantity and or improve its quality, moreover it will resolve
various problems face by refiner at CDU & de-salter process due to reprocessing of
emulsion.
The present ETP process and technology has limitation to further reduce quantity and or
to improve quality of emulsion because of very tight emulsion. As per the literature, yet
there is no any solution known to us which is adopted by petroleum refining industry or
may be technology not commercially viable.
Looking to the above problems, crude oil refiner always strives to reduce quantity of
emulsion generation as well as to improve its quality. Therefore, there is a need to
develop more effective effluent treatment process (ETP) where crude oil de-salter brine
water received for processing to recollect oil.
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Object and summary of the invention:
The main object of this invention is to develop a better process for reclamation of oil-inwater
emulsion collected after treatment at ETP from crude oil de-salter brine water.
Another objective of the present invention is to develop a better process for reduction of
emulsion quantity.
Another objective of the present invention is to develop a better process to improve
emulsion quality.
Another objective of the present invention is to reduce water from emulsion.
Another objective of the present invention is to reduce sediments from emulsion.
Another objective of the present invention is to reduce water soluble metal elements.
Another objective of the present invention is to reduce metal elements bonded with
sediments (organometallic molecules).
Another objective of the present invention is to reduce processing problems experienced
at crude oil de-salting & distillation by petroleum refiner.
Another objective of the present invention is to provide easily implementable process at
low cost.
Another objective of the present invention is to reduce water from emulsion.
In order to achieve the afore-said objectives, the present invention provides a novel
process for reclamation of oil-in-water emulsion collected after treatments at ETP from
crude oil de-salting brine water.
As per the first aspect, the present invention provides a twostep process, wherein, in first
step, oil in water emulsion collected after treatment at ETP from crude oil de-salter brine
water at ETP is treated with novel radiation technique which separate maximum water
and partially sediments and convert in to water in oil emulsion. In the second stage,
6
partially reclaimed oil is mixed with aromatic solvent and centrifuged to separate residual
water and sediments from emulsion.
Description of the drawings:
The foregoing and further objects, features and advantages of the present subject matter
will become apparent from the following description of exemplary embodiments with
reference to the accompanying drawings, wherein like numerals are used to represent
like elements.
It is to be noted, however, that the appended drawings illustrate only typical
embodiments of the present subject matter, and are therefore, not to be considered for
limiting of its scope, for the subject matter may admit to other equally effective
embodiments.
Figure 1 illustrates the basic reclamation process for oil-in-water emulsion collected from
crude oil de-salter brine water at ETP unit, which reduce emulsion quantity, reduce water
from emulsion, reduce water soluble metal impurities, reduce organometallic impurities
and hence it improve quality of emulsion also. Moreover it will resolve various problems
face by refiner at CDU & de-salter process due to reprocessing of emulsion.
Figure 2 illustrates the microscopic image of the oil-in-water emulsion [10], ultrasonic
treated oil [13], reclaimed oil [16], and separated water with sediments [12, 14].
Figure 3 illustrates B1 is oil-in-water emulsion [10] and B2 the qualitative visual
separation of oily layer at top and water with sediments at bottom in laboratory scale
batch ultrasonic treatment experiment.
Figure 4 illustrates B10 is change in appearance of emulsion after 120 minute
irradiation time in pilot scale batch process.
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Detailed description of the invention:
The following presents a detailed description of various embodiments of the present
subject matter with reference to the accompanying drawings.
The embodiments of the present subject matter are described in detail with reference to
the accompanying drawings. However, the present subject matter is not limited to these
embodiments which are only provided to explain more clearly the present subject matter
to a person skilled in the art of the present disclosure. In the accompanying drawings,
like reference numerals are used to indicate like components.
The specification may refer to “an”, “one”, “different” or “some” embodiment(s) in several
locations. This does not necessarily imply that each such reference is to the same
embodiment(s), or that the feature only applies to a single embodiment. Single features
of different embodiments may also be combined to provide other embodiments.
As used herein, the singular forms “a”, “an” and “the” are intended to include the plural
forms as well, unless expressly stated otherwise. It will be further understood that the
terms “includes”, “comprises”, “including” and/or “comprising” when used in this
specification, specify the presence of stated features, integers, steps, operations,
elements, and/or components, but do not preclude the presence or addition of one or
more other features, integers, steps, operations, elements, components, and/or groups
thereof. It will be understood that when an element is referred to as being “attached” or
“connected” or “coupled” or “mounted” to another element, it can be directly attached or
connected or coupled to the other element or intervening elements may be present. As
used herein, the term “and/or” includes any and all combinations and arrangements of
one or more of the associated listed items.
The figures depict a simplified structure only showing some elements and functional
entities, all being logical units whose implementation may differ from what is shown.
The present invention provides a process for reclamation of oil-in-water emulsion which
is verified by using actual oil-in-water emulsion collected from ETP unit and experimental
work done with laboratory scale & pilot scale equipment.
The present process is first time applied for oil in water emulsion collected after treatment
at ETP from crude oil de-salter brine water.
8
As per the first aspect Figure 1 represent the invented process, where the crude oil blend
[1] mixed with emulsion (extracted oil) [19] and other refinery slop oil [20] and feed to
the de-salter system [2] to remove water with dissolve salt and sediments, de-salted
crude oil [3] from top send to CDU process and brine water [4] drained from de-salter
bottom out let send to settling pond [5] and then emulsion skimmed off from top surface
of pond by belt system or other suitable system. The oil-in-water emulsion [7] send to
next settling tank [8]. After draining separated water [9] from bottom, the oil-in-water
emulsion [10] send to ultrasonic treatment system [11], where separated water with
sediments [12] from bottom send to ETP process [21] for further treatment and from
top, improved quality oily emulsion layer [13] send to centrifuge process [14] where
approx. 50 % volume of aromatic solvents added, after centrifuging, separated water &
sediments drained from bottom [18] and reclaimed (extracted) oil with solvent [19] send
to de-salter feed for reprocess. Basic drawing of ultrasonic system [11] attached here
separately.
De-salting Treatment:
Crude oil received at COT tankage through Jetty. After settling and draining of water, it
is pump to refinery for refining process. Crude oil blend [1] is prepared through on-line
blending system from various crude oil to meet the crude oil distillation unit feed criteria.
As explained in figure 1, collected emulsion at ETP [19] + refinery slop oil [20] generated
from other refinery processes is transport via pipeline for reprocessing and mixed with
crude oil blend [1]. Adequate quantity (5 to 6%) of demineralize water is being added to
dilute the water dissolved salt and heated up to 145 Deg C, then it feed to the de-salter
system [2]. The de-salter system, separate the water with dissolved salt & sediments
(sludge) by providing settling time in the horizontal vessel. The electric current is applied
to promote phase separation. De-salted crude oil [3] from top out let of de-salter [2] is
going for distillation process and brine water [4] with dissolved salt & sediments drained
from bottom of de-salter vessel out let. Small quantity of crude oil also gets carry over
with brine water [4]. The quantity of crude oil in brine water depends on multiple factors
viz de-salter design, operating parameters, operating condition as well as crude oil
quality. The concentration of oil in brine water is found to be in the range of few ppm to
10 % vol. The oil (hydrocarbon) needs to be recollect to save the fuel as well as to
minimize losses. Also it is necessary to control ETP operation.
Recollection of oil (Hydrocarbon) from de-salter brine water:
9
According to presnet process explained in figure-1, brine water [4] from de-salter bottom
out let send to open pond [5], where floated oily emulsion skimmed off through belt
system or suitable system and then skimmed emulsion send to settling tank [8] via
pipeline [7] and separated water & sediments from bottom out let [6] send to effluent
treatment plant. After 24 to 48 hours of settling time with or without heating treatment,
water drained from settling tank [8] bottom out let [9] and oil-in-water emulsion [10]
send to ultrasonic treatment system [11].
The quantity of oil-in-water emulsion [10] is very high and the emulsion is mainly having
water, heavy hydrocarbon oil, sediments and good amount of undesirable metal elements
viz iron, sodium, calcium, magnesium, aluminium, silica, chloride, sulphate etc. as
mentioned in Table 1 of summarized test results of experimental study work.
The quantity of oil-in-water emulsion:
The existing process of petroleum refinery is generating oil-in-water emulsion [10] in the
range of 0.2 to 1.0 % of its design crude oil throughput. For 20 MMTPA refinery, it is in
the range of 40000 to 200000 MT / year.
The present process and technology has limitation to further reduce quantity of oil-inwater
emulsion and/or to improve its quality because of very tight emulsion or nature of
emulsion.
Oil-in-water emulsion collected after treatment at ETP from de-salter brine water could
be either reprocess at refinery or can be disposed of according to legal compliance
process. Reprocessing at refinery is a cheap option than any other options.
Due to huge quantity and worst quality of oil-in-water emulsion [10], crude oil refinery
facing many problems while reprocessing emulsion even at lower concentration (<1 % )
of crude throughput viz,
1) The huge quantity of emulsion is reducing refining capacity and increasing
processing cost hence it has very big financial impact on GRM due to high reprocessing
cost (2 to 4 USD / barrel of emulsion), also consume extra energy at different stages,
require multiple storage, treatment and handling facilities ( tanks, chemicals, mechanical
and heating resources). It has adverse impact on environment as well as it increases
hazardous risk.
10
2) The worst quality of emulsion (high level of water and sediment in tight emulsion
form) is destabilize de-salter & CDU operation, generating more slop oil during de-salting
process and creating vicious cycle of emulsion.
3) Some time, oil-in-water emulsion generation is very high and it is difficult to
manage inventory, hence it become compulsion to reprocess within time frame even at
the cost of more CDU throughput loss.
4) It increase fouling, corrosion and frequent breakdown.
5) It also impacting on aviation turbine fuel (ATF) production with respect to
deteriorating of ATF colour.
Ultrasonic treatment to reclamation of oil-in-water emulsion:
As explained in Figure 1, oil-in-water emulsion [10] feed to the invented ultrasonic
treatment system [11]. The ultrasonic treatment consist of SS tank with required
ultrasonic frequency & wattage transducers and stirring/ heating mechanism. The
ultrasonic irradiation generates compressions and rarefactions in the oil-in-water
emulsion. The compression cycle create a positive pressure on the emulsion by pushing
molecules together and the rarefaction cycle create a negative pressure by pushing
molecules from each other, ultimately it generates microbubbles, which grown further
and collapse down results into shock waves which raise pressure and temperature. The
increase of liquid temperature reduces viscosity of emulsion, which helps to mass
separation of oil, water, and sediments.
The present ultrasonic treatment tested with 9 litre bath capacity having 37 KHz
frequency with 0.5 kilowatt power and also by using pilot plant with 500 liter capacity
bath having 27 KHz frequency and 8.4 Kilowatt power. The settling time is studied in the
range of 5 to 360 minute. Both the processes viz batch as well as continuous process
verified at laboratory scale with various actual samples of oil-in-water emulsion [10]
collected at ETP from crude oil de-salter brine water [4].
After ultrasonic treatment [11] with or without chemical diluents and or additives,
separated water with sediments drained from bottom out let [12] send to ETP for further
process. The top partially reclaimed oily emulsion layer [13] send to centrifuge technique
[14] for further quality improvement.
The experimental test results of partially reclaimed oily emulsion [13] are tabulated in
Table 1 and indicating that, the ultrasonic treatments is capable to,
A) Reduce up to 65% emulsion quantity
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B) Separate up to 90% water present in emulsion
C) Separate up to 30% sediments present in emulsion.
Centrifugal Treatment:
As explained in figure 1 the partially reclaimed oily emulsion collected after ultrasonic
treatment [11] is mixed with 50% aromatic solvent (toluene or refinery solvent
reformate) and feed to centrifugal system [14]. The solvent will reduce density and
viscosity of material hence it helps to improve separation of water and sediments using
centrifuge process. After centrifugal treatment [14], from bottom [15], separated water
& sediments send to ETP and top layer of separated oil [16] send to tank [17] for further
settling & reprocessing.
The quality of reclaimed oil is tested at laboratory and test results are tabulated in table
1.
As explained in Figure 1, reclaimed oil with solvent [16] get settling time ( approx. 24 to
48 hour ) at tank [17], after settling, separated water & sediments from bottom out let
[18] send to ETP [21] and from top fully reclaimed oil [19] send to refinery for
reprocessing. If required, other slop oil generated from refinery [20] can be added into
pipeline. Optionally solvent also can be separated by distillation process for reuse.
Automatic level control mechanism as well as other atomization can be used for safely
operation of process. The refiner can also reprocess partially reclaimed emulsion [13], if
quality of emulsion found acceptable.
Experimental Study Work and Test Results:
Various laboratory scale qualitative and quantitative experiments are conducted on actual
oil-in-water emulsion collected after treatment at ETP from de-salter brine water are
describe below. In this experimental study work following aspects are considered,
1) Development of improved process for reclamation of oil-in-water emulsion
collected after treatment at ETP from de-salter brine water to reduce emulsion generation
and improve its quality.
2) Experimental work using various irradiation techniques.
3) Experimental work using various chemicals.
4) Experimental work using irradiation combined with different chemicals.
5) Quantification of reclaimed (fully and partially) emulsion, water, and sediments
separated from oil-in-water emulsion.
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6) Testing of various quality parameters of reclaimed (fully and partially) emulsion,
water and sediments separated from oil-in-water emulsion.
7) Laboratory scale experiments with 9 litre capacity US bath.
8) Pilot scale experiments with 500 lit capacity US bath.
9) Feasibility of invented process with respect to cost, availability of technology,
operational safety, impact on environment and easy implementation in the field,
Details of equipment and materials used for laboratory experiments:
Ultrasonic Bath:
1) Ultrasonic bath with 9 litre capacity, 37 MHz frequency, and 500 watt power
2) Ultrasonic bath with 500 litre capacity, 27 MHz frequency and 8400 watt power
Laboratory Centrifuge: Design as per ASTM D 4007 test method to check bottom
sediments and water (BS&W) with operating parameters viz RPM 2500, time 20 minute
and temperature 50 Deg C.
Glass Wares: Bottles (200, 500 and 2000ml capacity), cylinders (100, 500 and 1000ml),
separating funnels (100, 250 and 500 ml), test tubes, volumetric flask.
Chemicals / additives: AR grade chemicals viz acetic acid, benzoic acid, citric acid,
oxalic acid, Ethylene diamine tetra acetic acid sodium salt and GR grade chemicals viz
poly aluminium chloride and aqueous demulsifier.
Solvent for sample preparation: AR grade Toluene, Heptane and refinery aromatic
stream (reformate)
Balance for sample weight: 0 to 210 gm and 0 to 5kg.
Filtering Device: 0.2 micron nylon filter paper, 10 ml syringe device and filtration
assembly with vacuum pump etc.
Test method used for testing: Water by ASTM D 4006, Sediment by ASTM D 473,
BS&W by ASTM D 4007 and metal elements By ICP-OES and aqueous anions by ion
chromatography etc.
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Qualitative Examination 1:
Figure 2 represent the oil-in-water emulsion [10], ultrasonic treated oil [13], reclaimed
oil [16] and separated water with sediments [12, 14].
Observations: The white spots in above images indicate the presence of water droplets
and black spots indicates the presence of sediment particles. The image a), b) and c) are
clearly indicate the reduction of water & sediments and improvement in quality of oil.
Qualitative Examination 2:
Figure 3 representing, B1 is oil-in-water emulsion [10] and B2 the qualitative visual
separation of oily layer at top and water with sediments at bottom in laboratory scale
batch ultrasonic treatment [11] experiment. The laboratory experiments done using
ultrasonic frequency 37 KHz with 0.5 Kw power with 30 minute irradiation time.
Observations: The bottle B2 clearly indicates that after ultrasonic treatment, the water
get separated & found to be at bottom layer and separated sediments found to be
accumulated at interface level in the water phase.
Summarized Test Results Of Experimental Study Work:
We have carried out multiple laboratory scale and pilot plant experiments and stage wise
process improvements & test results are summarized in below Table 1.
Table 1
Process
Stages =>
Initial Stage
( Before
Treatment )
Middle Stage
( Partially
reclaimed
emulsion)
Final Stage
(fully
reclaimed oil )
Remarks/Observations
Parameter Oil in Water
emulsion
Collected from
Tank [10]
Separated oil
after Ultrasonic
Treatment
[13]
Separated oil
after centrifugal
treatment [16]
and solvent
Evaporation
-
Density at
25⁰C, gm/ml 0.9701 0.9481 0.9402
There is stage wise
reduction in density
Main
Composition % % %
Oil % Vol 25 to 40 73 to 80 99 Stage wise oil % improved
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Water % Vol 60 to 75 20 to 27 <1
Stage wise water % get
reduced
Sediments %
Wt. 0.5 to 1.0 1.0 to 2.5 <0.05
Sediments get separated in
final stage
Undesirable
Metal
Elements wt. ppm wt. ppm wt. ppm
Na, wt. ppm
965 175 <1
Stage wise water soluble
metal reduced, measured by
ICP-OES
Fe, wt. ppm 680 2600 54 Metal elements of
organometallic reduced
drastically in final stage,
measured by ICP-OES
Ca, wt. ppm 701 1700 3.7
Si, wt. ppm 201 670 3.5
Al, wt. ppm 221 822 6.0
Mg, wt. ppm 138 315 2.0
P, wt. ppm 32 71 <0.5
Zn, wt. ppm 19 50 1.0
Cu, wt. ppm 3.4 8.4 0.8
Mn, wt. ppm 5.1 20 0.1
Cr, wt. ppm 2 4.8 0.2
Pb, wt. ppm ND 2.5 ND Very trace level
Chloride, ppm 1304 150 76 Aqueous anions by Ion
Chromatography
Sulfide+
Sulphate
ppm
72 104 18
Observations:
Ultrasonic Treatment:
Various laboratory scale ultrasonic radiation treatment experiments conducted on actual
oil-in-water emulsion [10] collected from ETP unit. After ultrasonic radiation treatment,
emulsion get partially reclaimed and separated oil & water tested for various quality
parameters. The observed test results are highly encouraging and found that invented
process is,
1) Improving quality of emulsion (Figure-2, image a and b).
2) Capable to convert oil-in-water emulsion (25% oil + 75% water) into water-in-oil
emulsion (75% oil + 25% water).
3) Capable to reduce up to 65 % of emulsion quantity.
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4) Capable to separate up to 90% water present in initial emulsion.
5) Capable to remove up to 30 % of sediments present in initial emulsion.
6) Capable to reduce elemental impurities viz iron, calcium, sodium, aluminum,
silicon, chloride etc present from emulsion.
7) Observations 1 to 6 are evidence of improvement in quality of emulsion and
reduction of emulsion quantity.
Centrifugal Treatment:
Test result obtained from various laboratory scale experiments conducted using solvent
dilution & centrifuge treatment on actual partially reclaimed oily emulsion [13] collected
after ultrasonic treatment [11] outlet are highly encouraging and found that centrifuge
treatment after ultrasonic treatment is.
1) Further improving quality of emulsion (Figure-2, image b and c) are clearly
indicates the improvements in quality of oil.
2) Capable to reduce water up to < 1 % vol.
3) Capable to reduce sediments up to < 0.05 1% wt.
4) Capable to improve % oil up to 99% vol.
5) Capable to reduce drastically elemental impurities viz iron, calcium, sodium,
aluminium, silicon, chloride etc. present after ultrasonic treatment.
6) Observations 1 to 5 are evidence of further improvement in quality of oil and
reduction of emulsion quantity.
Conclusions:
Based on test results of various laboratory experiments and observations of invented
ultrasonic process followed by addition of solvent & centrifuging treatment for
reclamation of oil-in-water emulsion collected after treatment at ETP from crude oil desalter
brine water, we conclude as follow:
1) Invented process is capable to convert oil-in-water emulsion into good quality of
oil (99% oil + <1.0% water + < 0.05% sediments).
2) The reclaimed oil (partially or fully) can be easy to reprocess with crude oil.
3) Invented process is capable to reduce up to 65 % volume of emulsion quantity
after first stage and up to 74% volume after second stage.
4) Invented process is capable to separate up to 99% volume water present in
emulsion after second stage.
5) Invented process is capable to reduce sediments up to <0.05 % wt. level.
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6) Invented process is capable to reduce undesirable elemental impurities > 90 % viz
iron, calcium, sodium, aluminum, silicon, chloride etc. present in emulsion.
7) Invented process has removed water, sediments, elemental impurities hence is
capable to improve quality of emulsion which is also evident in density of emulsion.
8) Invented process is reducing significant amount of emulsion quantity and
improving quality of emulsion, hence it will help to resolve following problems
experienced by petroleum refinery due to huge quantity as well as worst quality of
emulsion viz.
a) The reduced emulsion quantity will allow refinery to process more crude oil as well
as avoid reprocessing cost, hence will lead to earn more profit. Also it will reduce
energy consumption at different stages, reduce facility requirements for storage,
treatment and handling (tanks, chemicals, mechanical and heating resources) of
emulsion. It will additionally reduce impact on environment and hazardous risk.
b) The improved quality of emulsion will reduce operational problems (destabilization)
at crude oil distillation & de-salter unit and improve de-salter efficiency. It will help
to breaking of vicious cycle of emulsion.
c) It will reduce fouling, corrosion and frequent breakdown.
d) It will reduce impact on ATF colour.
Pilot Skid Batch Process Trial:
Pilot skid was installed with three-meter cube feed tank for oil in water emulsion also
called slop oil near R&D laboratory for batch process trials. As and when required, slop
oil was transported using gulley sucker from ETP Tank-C / B which is collected from desalter
brine water and unload into feed tank. Various trials were conducted for process
optimization and performance verification. The performance test results after
optimization are tabulated in below table-2
Table-2
Date
%
Water
in slop
oil
%
Sedimen
ts in
Slop oil
% Water Separated after US
treatment
% Water
Separation
Efficiency
%
Sediment
Reduction
30 Min 60 Min 90 Min 120 Min
18.03.21 76.9 2.06 26 53 56 61 79 21
25.03.21 78.0 1.92 53 61 73 73 94 49
31.03.21 78.0 2.06 51 63 72 73 94 38
01.04.21 66.5 2.63 18 29 40 46 69 29
17
05.04.21 72.0 2.9 - 53 61 61 85 37
Average 74.3 2.31 37 52 60 63 84 35
Observations:
Following are the observations derived from the test results of batch process trial,
1) Pilot skid trial has demonstrated average 63% reduction of slop oil quantity at 120 min
irradiation time and highest reduction achieved up to 73 %.
2) Pilot skid trial has demonstrated average water separation efficiency 84 percentage which
is close to the laboratory scale experiments done using small capacity ultrasonic bath and
highest water separation achieved up to 94 %.
3) Pilot skid trial has demonstrated average sediments removal 35 percentage which is close
to the laboratory scale experiments done using small capacity ultrasonic bath and highest
sediment removal achieved up to 49 %.
4) Pilot skid performance was verified & optimized for irradiation time and stirring effects.
Pilot Skid Continuous Process Trial:
After verifying batch process performance at R&D laboratory, the performance of
invented process discussed with concern officials of operation and technical service
department to conduct continuous process trail at ETP to verify the performance at field.
The pilot skid was shifted to effluent treatment plant (ETP) for field trial using continues
process. The feed emulsion arrangement done from ETP slop oil tank A & B after settling
and separated oil & water connected to ETP feed sump. Separated water and oil flow
was manually measured during trials and used for performance calculation. All plant
safety SOPs were followed during trails.
ETP operation team has conducted various field trials (total 83 running hours) with
continuous process with variable parameters to check the performance as well as
optimize operation parameters viz feed flow rate, effect of irradiation time, process
temperature, effect of stirring, effect of interface level etc. Also required samples (feed
slop oil and separated oil & water) were collected & tested at laboratory to evaluate
performance of invented process. Performance test results after optimization are
tabulated in below table 3.
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Table-3
Trial
Date
Trial
Duratio
n, Hrs
Feed
Slop
Oil
M3/hr
Separat
ed oil,
M3/hr
Separa
ted
Water,
M3/hr
Separate
d Water
%
Water %
in feed
Slop Oil
Water
Separation
efficiency
%
TSS
Removed
%
27-07-21 5.5 0.6 0.4 0.3 43 65 66 -
11-08-21 6.5 1 0.5 0.4 44 72 62 -
13-08-21 3.5 1.4 0.8 0.6 43 70 61 -
14-08-21 6 0.9 0.4 0.4 50 71 70 34
16-08-21 10 1.1 0.6 0.5 45 70 65 22
18-08-21 7 1.4 0.8 0.6 43 73 59 -
24-08-21 7 1.6 0.8 0.8 50 74 68 -
26-08-21 5.5 1.8 1.0 0.8 44 67 66 27
Average Value 45 70 65 28
Observations:
Following are the observations derived from the test results of continuous process field
trial,
1) Pilot skid trial has demonstrated average 45% reduction of slop oil quantity and highest
reduction achieved up to 50 %.
2) Pilot skid trial has demonstrated average water separation efficiency percentage slight
lower than past experiments and highest water separation achieved up to 74 %.
3) Pilot skid trial has demonstrated average sediments removal percentage close to the past
experiments and highest sediments removal achieved up to 34 %.
4) Pilot skid operated with continuous process in the range of 0.6 to 1.8 meter cube per
hour and observed highest 0.8 meter cube per hour water separation.
5) Skid was continuously operated up to 10 hours to see the performance of system and
found to be satisfactory.
6) Skid performance was verified & optimized for stirring and temperature effect.
Conclusions:
Based on test results of both (batch and continuous process) trials observations, it is
concluded as below,
1) Pilot skid performance in batch trial at Lab and continuous process at field trial is found
to be satisfactory and close to the expectations.
2) Pilot skid is reducing slop oil generation up to 50% volume in continuous process and up
to 70% in batch process.
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3) Pilot skid is removing sediments up to 34% in continuous process and up to 49% in batch
process.
4) Invented process is removing water, dissolved salt and sediments from ETP slop oil hence
it is improving the quality of slop oil.
Pilot skid trials performance data will be highly useful to design large scale design to
achieve similar performance and conduct further R & D work to improve the performance.
Advantages of the invention:
The present invention is globally applicable to crude oil petroleum refinery. The present
invention is capable to convert oil in water emulsion to good quality oil and has many
benefits to crude oil refining industries viz.,
Based on test results of various laboratory experiments and observations of invented
process for reclamation of oil-in-water emulsion collected at ETP from crude oil de-salter
brine water using ultrasonic irradiation treatment followed by addition of solvent &
centrifuging, we envisaged advantages are as follow:
1) Invented process will convert oil-in-water emulsion into good quality of oil (99% oil +
<1.0% water + < 0.05% sediments).
2) The reclaimed oil (partially or fully) will be easy to reprocess with crude oil.
3) Invented process will separate up to 90% water at first stage and up to 99% volume
of water present in emulsion after second stage.
4) Invented process will reduce sediments up to <0.05 % wt. level.
5) Invented process will reduce undesirable elemental impurities > 90 % viz iron, calcium,
sodium, aluminum, silicon, chloride etc. present in emulsion.
6) Invented process will remove water, sediments, elemental impurities hence it will
improve quality of emulsion.
7) Low cost solution and technology easily available in the market.
8) It is safe to operate in the field.
9) Invented process will reduce significant amount of emulsion quantity and improve
quality of emulsion hence it will help to resolve following problems experienced by
petroleum refiner due to huge quantity as well as worst quality of emulsion viz.
a) The reduced emulsion quantity will allow refiner to process more crude oil as well
as avoid reprocessing cost, hence will lead to earn more profit. Also it will reduce
energy consumption at different stages, reduce facility requirements for storage,
treatment and handling (tanks, chemicals, mechanical and heating resources) of
emulsion. It will additionally reduce impact on environment and hazardous risk.
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b) The improved quality of emulsion will reduce operational problems (destabilization)
at crude oil distillation & de-salter unit and improve de-salter efficiency. It will help to
break vicious cycle of emulsion.
c) It will reduce fouling, corrosion and frequent breakdown.
d) It will reduce impact on ATF colour.
The invented process is having high returns on investment and easy to implement in the
field hence it will give huge benefits to the refiner globally.
Although the invention has been described with reference to specific embodiments, this
description is not meant to be construed in a limiting sense. Various modifications of the
disclosed embodiments, as well as alternate embodiments of the invention, will become
apparent to persons skilled in the art upon reference to the description of the invention.
It is therefore contemplated that such modifications can be made without departing from
the spirit or scope of the present invention as defined.
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We clam:
1. A process for reclamation of oil-in-water emulsion collected after treatment at ETP from
crude oil de-salter brine water comprising the steps of:
- collecting oil-in-water emulsion after treatment at ETP from crude oil de-salter brine
water at ETP and treating with radiation to separate maximum water and partially
sediments and convert into water in oil emulsion;
- mixing partially reclaimed oil with aromatic solvent and centrifuging to separate
residual water and sediments from emulsion.
2. The process as claimed in claim 1 wherein,
- the crude oil blend [1] is mixed with emulsion (extracted oil) [19] and other refinery
slop oil [20] and fed to the de-salter system [2] to remove water with dissolve salt
and sediments,
- sending the de-salted crude oil [3] to CDU process and draining the brine water [4]
from de-salter bottom outlet to settling pond [5]
- skimming off the emulsion from top surface of pond by belt system or other suitable
system;
- sending the oil-in-water emulsion [7] to next settling tank [8];
- after draining separated water [9] from bottom, sending the oil-in-water emulsion [10]
to ultrasonic treatment system [11], where the separated water with sediments [12]
from bottom is send to ETP process [21] for further treatment;
- from top, improved quality oily emulsion layer [13] is sent to centrifuge process [14]
where approx. 50 % volume of aromatic solvents added;
- after centrifuging, separating water & sediments drained from bottom [18] and
reclaimed (extracted) oil with solvent [19] send to de-salter feed for reprocess.
3. The process as claimed in claim 1, wherein the crude oil blend [1] is prepared through online
blending system from various crude oil.
4. The process as claimed in claim 1, wherein the existing process of petroleum refinery
generates oil-in-water emulsion in the range of 0.2 to 1.0% of crude oil throughput.
5. The process as claimed in claim 1, wherein the oil-in-water emulsion collected after
treatment at ETP from de-salter brine water is either reprocess at refinery or is disposed
of.
6. The process as claimed in claim 1, wherein the ultrasonic treatment consist of SS tank with
required ultrasonic frequency & wattage transducers and stirring/ heating mechanism.
7. The process as claimed in claim 1, wherein the ultrasonic irradiation generates
compressions and rarefactions in the oil-in-water emulsion.
8. The process as claimed in claim 1, wherein the increase of liquid temperature reduces
viscosity of emulsion, which helps to mass separation of oil, water, and sediments.
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9. The process as claimed in claim 1, wherein the partially reclaimed oily emulsion collected
after ultrasonic treatment [11] is mixed with 50% aromatic solvent (toluene or refinery
solvent reformate) and feed to centrifugal system [14].