PAZAS14 tkcl 401-T-001 crude oil of tec P14_382

Transcription

ITW S.r.l.
da S. Cusuman
no
Zona ASI – C.d
96011 Augusta
a (SR)
Italy
9 (0931) 766011
Tel. / Fax +39
E-mail: [email protected]
VAT: IT012704
480898
Innovative
Technologies
T
Worldwide
CO
ONFIDENT
TIAL
Augustta, Novemb
ber 27, 20144
PAZ ASHD
DOD OIL REFINERY
R
Y
ASHDOD,, ISRAEL
Our Ref. P
P14/382/MF
F
To the kindd attention of
o
Re:
Dorel M
Moskowitz, Maintenacee Division M
Manager
OIL
L RECOVE
ERY AND G
GAS-FREE
EING OF 400-T-001
4
C
CRUDE TA
ANK
With referrence to your enquiry, please finnd attached our techniccal and com
mmercial offer for thee
sludge recoovery and gas
g freeing of
o tank 400--T-001 conttaining Crud
de Oil.
a
pleasee do not hes itate to conttact us.
Should anyy question arise,
Kind regarrds
ITW S.r.l.
Chairman
Dr. Marcelllo Ferrara
___
___________
___________
___________
__________
___________
_____________________
____
The contentts of this pap
per are confid
dential and b
belong to ITW
W know-how and/or intelleectual prope
erty. Transferr
to any third party of anyy of the conte
ents of this p aper is subje
ected to a Se
ecrecy Agreeement to be undersigned
d
with ITW an
nd is prohibiited unless specifically
s
a
authorized in writing by ITW. The usse of the con
ntents of thiss
paper is striictly restricte
ed to the evalluation of ITW
W technologies only.
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ITW
1. INTRODUCTION
Traditional tank cleaning methods require the tank to be taken out of service for a long period of
time and are associated with health and safety problems for the workers, together with
environmental problems (VOC emissions and waste generation).
Sludge extracted with traditional tank cleaning methods contains a certain amount of water and
hydrocarbons, both of them acting as solid binders and contributing to increased waste disposal.
As solids amount is in the range of 1-10%, by recovering the remaining 90-99%, waste disposal will
be dramatically reduced, as well as cleaning time.
ITW has developed and patented a novel technology capable of fully recovering precipitated sludge.
The final product is fully stable, reusable and does not give rise to any subsequent precipitation.
ITW technology uses proprietary chemicals in order to solubilize and stabilize the sludge, so the
sludge is transformed into a fully reusable product.
ITW chemicals have proven very effective not only in tank sludge recovery and reutilization, but
also in Production Units sludge/coke material dissolution, again transforming them into a fully
reusable product.
Hydrocarbons recovered from the sludge normally range between 90-98%.
ITW can perform tank cleaning on a turn-key basis, starting from the chemical pretreatment up to
the achievement of gas-free conditions.
At the end of ITW job, gas-free certification will be issued.
2. TECHNICAL PREMISES
The tank has the following characteristics:
Tank
Product
Volume (m3)
Diameter (m)
Sludge (m3)
Roof
400-T-001
Crude Oil
30000
48.768
5603
Floating
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The contents of this paper are confidential and belong to ITW know-how and/or intellectual property. Transfer
to any third party of any of the contents of this paper is subjected to a Secrecy Agreement to be undersigned
with ITW and is prohibited unless specifically authorized in writing by ITW. The use of the contents of this
paper is strictly restricted to the evaluation of ITW technologies only.
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3. ITW APPROACH TO TANK CLEANING
Generally the main steps of the complete ITW cleaning procedure are the following:
a)
b)
c)
d)
e)
f)
g)
h)
i)
j)
Commissioning
Connection of the equipment for chemical pretreatment and tank recycle
Chemical pretreatment for hydrocarbon recovery
Pumping out and filtering of recovered hydrocarbons
Chemical water washing for safe entry
Forced ventilation
Manpower entering the tank
Manual extraction of residues
Final cleaning
Gas-free certification
4. ITW TECHNOLOGY FOR OIL RECOVERY AND SAFE ENTRY
Oil recovery from sludge
ITW has developed and patented an innovative technology for tank cleaning, which utilizes
patented asphaltenes stabilizers and paraffin stabilizers.
Traditional mechanical tank cleaning involves prolonged tank downtime, followed by
environmental problems for waste disposal and VOC emissions.
Sludge extracted with traditional manual tank cleaning contains water and hydrocarbons, both
acting as solids binders and therefore contributing to increasing sludge volume.
The same applies to sludge suspension methods (e.g. COW).
According to the ITW technology, hydrocarbons are recovered from the sludge by addition of a
patented chemical, containing patented asphaltene stabilizers and paraffin stabilizers.
The patented chemical is utilized to dissolve the sludge and turn it into a stable pumpable fluid.
Sludge dissolution occurs due to the chemical action of the patented chemical during circulation of
the oil phase.
The asphaltenes in the sludge are in the form of a precipitate, hence strongly associated.
Moreover, when the sludge contains sediments, a strong aggregation between sediments and
asphaltenes occurs.
In such a case, precipitated asphaltenes incorporate sediments thereby creating non-filterable
macrostructures.
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In the case of sludge suspension methods, due to sediments carry-over, fouling problems may
occur. Sometimes, filter plugging and loss of suction in the crude oil pumps has led to unscheduled
shutdown of the Topping Unit.
ITW chemicals have the capability to stabilize asphaltenes, and in general heavy hydrocarbons, to
such an extent that they are not further aggregated, hence filterable. In such a way, the sediments
are freed from the sludge, i.e. the heavier hydrocarbon portion (which contributes to the formation
of non-filterable macrostructures) is chemically stabilized and fluidized.
With current technologies, the release of sediments from asphaltenes is not possible, as asphaltene
structures are not disjointed.
The concept of ITW Technology can be better illustrated as follows:
ITW chemical
Sediment
Heavy hydrocarbons
Therefore, by circulating the oil containing ITW chemicals, sediments will be left at tank bottom.
It is important to underline that the oil phase achieved from the sludge after ITW treatment is
filterable, stable, fully reusable and compatible with any hydrocarbon stock.
This is also evident from the above picture, wherein asphaltenic/paraffinic macrostructures are
stabilized in single, smaller particles or fully dissolved.
By utilizing ITW technology for tank cleaning, it is therefore possible to achieve the following
results:




recovery of hydrocarbons
reduction of cleaning time
reduction of sludge disposal costs
safe and environmentally friendly operations.
The sludge is therefore solubilized and stabilized in the carrier and not dispersed, so the sludge is
fully recovered.
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For the cleaning of the Crude Oil tank the selected chemical is MEG F958M.
MEG F958M is a blend of patented asphaltene stabilizers and paraffin stabilizers.
Moreover, MEG F958M also contains a patented emulsion breaker, which is very fast in separating
water, even at ambient temperature and with high solid contents.
By separating the water at the bottom of the tank, sludge disposal will be further reduced and the
recovered oil will be more valuable.
No centrifugation is therefore required to separate water from sludge and the recovered oil will have
a < 0.5 vol % water content.
Normally, we achieve a water content in the recovered oil of < 0.1%.
MEG F 958M has the following features:
-
does not contain any metallic compound
does not contain any catalyst poison that could harm catalytic refinery processes
does not contain any halogen compound
does not contain any compound which, at operating dosages, can be a poison for waste water
treatment plants
does not contain any compound which can be harmful for plant metallurgies
does not contain any compound which can be dangerous during handling
does not contain any carcinogenic compound
does not give rise to any secondary reaction.
The tank will be circulated and MEG F958M injected during the circulation.
Tank circulation will be accomplished by connecting ITW mobile pumps to the bottom valve(s) and
discharging the fluid into rotary nozzles placed on roof/shell manways.
Additional circulation will eventually be performed by means of the tank transfer line and/or mixers
(when in place).
Such rotary nozzles will be placed in the commissioning phase, before tank circulation; all the
operation will be performed by using Personal Protection Equipment and all the other prescriptions
dictated for such case.
The effect of MEG F958M will be to stabilize/solubilize the sludge during circulation.
Sludge level decrease will be monitored by means of sounding.
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MEG F958M will be injected together with a carrier available in the refinery (e.g. gasoil).
MEG F958M will solubilize the sludge during tank circulation; at the end of the circulation a
pumpable/stable fluid will be obtained.
The stabilized fluid will be then directly transferred into another PAZ ASHDOD refinery tank for
reuse/reprocessing; prior to pumping the oil out, BS&W and sediment size will be measured for
acceptance.
Please note, the tank has currently 3 m of sludge, which renders almost impossible manual cleaning
activities.
ITW technology is therefore the best choice for cleaning the tank, as most of the sludge will be
recovered with no man entry, by the action of MEG F558M, with the operating personnel staying
outside of the tank.
Addtionally, by treating and recovering the sludge inside the tank, all the oil will be recovered at the
same time (as opposite to the batch processes, e.g. centrifugation).
Among the others, this will avoid transferring the recovered oil into daily tank(s) provided by the
contractor and will dramatically reduce cleaning time.
We respectfully remind you, ITW patented chemicals have already been successfully used to
stabilize/solubilize the deposits in refining production units such as e.g. CDUs, VDUs, VBUs,
FCCUs, Asphalt, ecc. by performing ITW Online Cleaning.
These types of deposits are far more difficult to stabilize/solubilize than those found in a tank.
Washing fluids have been always fully reused/reprocessed with no operational problem.
This gives you a clear indication of the results achievable by using ITW Technology.
Safe entry conditions achievement
If the scope of the work is reducing sludge amount and recovery of hydrocarbons with no man
entry, after the ITW’s oil recovery from sludge the tank can be set back in operation.
In case safe entry conditions for the maintenance/inspection personnel are required, gas-free
certificate of the tank is mandatory.
ITW achieves that by injecting another patented chemical, MEG F516P, in the water phase.
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MEG F516P will temporarily solubilize hydrocarbons in water, thereby removing them from metal
surfaces.
Whilst quickly removing hydrocarbons from the equipment, the chemical will simultaneously:
 eliminate H2S/mercaptans emissions
 reduce benzene inside the equipment down to < 1 ppm
 eliminate pyrophoric solids problems
MEG F516P is a multifunctional chemical which contains, among the others, patented compounds
which improve hydrocarbons’ affinity to water.
MEG F516P is capable of transforming water into a temporary “solvent” for hydrocarbons.
MEG F516P does not create any emulsion with hydrocarbons.
MEG F516P also eliminates any problem related to pyrophoric solids ignition.
MEG F516P does not contain any emulsifier/acid/base/permanganate and is a biodegradable
product.
This will give the maximum guarantee over water reuse in waste water treatment plant.
These features are particularly important as, by simply settling, a spontaneous and immediate
separation of hydrocarbons from water will occur.
No emulsion breaker or calcium chloride is therefore necessary to separate hydrocarbons from
water.
Moreover, the wastewater treatment plant will not be overloaded by hydrocarbons, as they will be
easily separated, e.g., in the API separator.
MEG F 516P is a very fast acting chemical in removing hydrocarbons from metal surfaces and,
therefore, the tank will be very quickly gas-freed.
MEG F 516P does not add any problem to waste water quality.
COD increase attributable to MEG F 516P is 2 ppm only.
Moreover MEG F516P is biodegradable (> 95%).
MEG F 516P poses no danger to plant/apparatuses metallurgies, as well as for any coating.
Aqueous solution of MEG F 516P has pH around 7.
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We kindly underline, as MEG F516P will not create any emulsion, water arising from ITW final
cleaning operations can be easily sent to sewer and then to waste water treatment plant.
After the pumping out and transfer of all the solubilized hydrocarbons, the cleaning of the tank will
proceed with additive water washing with MEG F516P.
This will further recover hydrocarbons and reduce hazards during tank entry.
Water will be introduced in the tank (about 50 m3 can be sufficient) along with MEG F516P.
MEG F516P will be circulated by means of ITW mobile pumps and rotary nozzles already installed
in the tank.
Circulation will last about 1-2 days.
After circulation oily water will be sent to API separator, wherein the oil will be skimmed and the
water will be sent to waste water treatment plant (as per normal operations).
MEG F516P will extract hydrocarbons from solids and from tank inner surfaces, thus achieving
multiple positive effects:
a.
b.
c.
d.
Reduction of LEL < 10%
Reduction of the H2S , mercaptans, benzene < 1 ppm
Reduction of hydrocarbon content in wasted solids
Quick achievement of tank safe entry
The use of MEG F561P will therefore eliminate all airborne emissions, which are typical when
performing conventional manual cleaning.
After washing with MEG F516P, a water washing (without additive) will be performed.
Finally, wall manways will be opened, together with roof manways, and forced ventilation (if
needed) will be performed to speed up tank entry.
No one of the above operations (both in the oil phase and in the water phase) is dangerous to any
coating.
Final cleaning
After the circulation steps, only a minimum amount of sludge will remain in the bottom of the tank.
Therefore, the cleaning will proceed in a manual manner in order to achieve the gas free
certification for the tank.
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After opening manways and eventual forced ventilation, the workers will enter the tank for
manually extracting all the residues in the bottom of the tank and place them in containers and/or
trucks for disposal.
Workers will entry the tank from a cleaning door, and cleaning will proceed therefrom.
Prior to manpower entering the tank, for safety reasons, PAZ ASHDOD refinery should schedule
the opening of at least 1 door in the tank shell. Such door will be opened by cold cutting and have a
size of about 3m (length) x 2m (height).
The packaging for wastes will depend upon the physical state of the residue and/or your
requirements.
To our experience the remaining sludge should be of the solid type.
Residual sludge extraction may be facilitated by sucking it by means of a vacuum truck sucker.
We hereby ask PAZ ASHDOD refinery to create a truck entrance from the main road to the basin,
this will be in any case useful to enter the equipment and/or to manage wastes.
The entrance and all the way to the tank should be paved in order to allow normal operations of
trucks under any weather conditions.
After extracting all the residual sludge from tank bottom, the workers will proceed to manually
remove any hydrocarbon residue inside the tank.
For this purpose some chemical can also be sprayed inside the tank to speed up the cleaning
procedure; water will be finally sprayed to remove all of the hydrocarbons. The cleaning will
continue until we will reach an oil free status of the metal surfaces.
All personnel entering the tank will be provided with all the safety equipment prescribed for the
particular conditions to be found inside the tank.
An active surveillance will also be provided.
To speed up operations, we hereby ask since now the authorization to work during weekends and/or
on holidays and/or on shift duties.
Surely, during circulation steps, we need to work on continuous shift duties.
VOC emission control
As ITW technology is based on closed loop circulation of patented chemicals, there is no need of
installing VOC emission control devices during sludge recovery.
Anyway, in case required by PAZ ASHDOD refinery, during the mechanical extraction of the
sludge left in the tank we can install a VOC emission control device to seal the cleaning door;
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vapours will be sucked by an Atex ventilator and passed through activated carbon filters prior to
releasing them in the atmosphere.
Alternatively, a mobile flare can also be used.
VOC emission control costs are not included in the commercial offer, unless required by PAZ
ASHDOD refinery.
5. ITW OPERATIONAL PROCEDURE - SUMMARY
In the specific case of Crude oil tank 400-T-001, the following steps will be put in place.
5.1. Homogenization of the tank
Tank will be circulated by means of our pumps with the target to homogenize the liquid phase, to
start dissolving the bottom sludge and to demulsify the hydrocarbons.
This circulation will last about 15 days. After this, a 1-2 days decant phase will follow.
5.2. Emptying of water from the tank
Water separated from the oil will collect at the bottom and will be drained to the oily sewer.
5.3. Emptying the tank from oil
The recovered dry oil will be pumped out and routed to another refinery tank for subsequent
reuse/reprocessing.
In case gas free conditions are not required, at this point the tank will be emptied from the
recovered oil and put back on service.
5.4. Achievement of safe entry conditions
If safe entry conditions are needed/requested, a circulation with water and F516P will be set-up.
This circulation will last about 1-2 days.
After washing with MEG F516P, a water washing (without additive) will be performed.
5.5. Manpower entrance
Manpower will entry the tank for manual removal and packaging of residual solids.
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The packaging to be used, transport and disposal of waste will be on PAZ ASHDOD refinery
duties.
5.6. Final cleaning
Final cleaning of tank internals will be provided.
6. CENTRIFUGATION
A special word is to be spent on centrifugation.
ITW will not perform centrifugation, because ITW technology does not need it.
As a matter of facts, the oil will be effectively recovered/stabilized and the water separated by
means of our patented MEG F558M.
Centrifugation is indeed needed by competitors, because they do not have any effective chemical
technology for oil stabilization and water separation.
By mechanically dispersing all of the sludge, they do need means for separating oil, water and
sediments.
Furthermore, centrifugation has no impact on oil properties in term of stabilization.
Any sludge dispersed with mechanical means will precipitate back into the receiving tank.
Please also note, what has been described for centrifugation also applies for emulsifiers and
demulsifiers which some companies claim to use.
Please see paragraph 15 for more details.
We can however perform centrifugation of manual extracted residues upon request.
In our experience, give the small amount of waste left after application of ITW technology, it is not
worth including a centrifugation step for the residues, because the delta cost for centrifugation will
not pay off the delta cost of the reduced amount of waste to be disposed of.
7. PAZ ASHDOD REFINERY SCOPE OF SUPPLY
Before starting ITW procedure, PAZ ASHDOD refinery will verify in duly time frame (i.e. before
the shipping of ITW apparatuses), the following items:
1. Test that a tank product outlet valve be operable and/or tank inlet line is not clogged.
2. Test the efficiency of water sump.
PAZ ASHDOD refinery should provide at least the following:
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a)
b)
c)
d)
ITW
Utilities
Electrical connections and electrical assistance
Hydrocarbon carrier
Access to the basin and paving, to avoid loss of operational time in case of bad weather
conditions
Containers for wastes (drums, trucks, or as applicable for oily waste), transport and disposal
thereof. This latter can also be included in ITW’s scope of work.
e)
The scheduled electric power requirement is about 150 kWh during the circulation phase.
8. ITW SCOPE OF SUPPLY
ITW supply will include, among the others, the following:
-
Projecting
Scheduling
Safety plans
Chemical products MEG F958M and MEG F516P
Safety supervision
Specialized manpower
Technical assistance
Monitoring during the application
Mob/demob of equipment
Circulation pumps
Washing turbines
Hoses
9. PRELIMINARY TIME SCHEDULE
Preparatory work will be held in our premises. We will need about 3-4 weeks from order date for
organization, loading and travel arrangements.
In order to reduce overall cleaning time, we require to prolong normal working hours to shifts, in
order to cover the jobs on a 24h basis.
10. SAFETY
ITW operates according to safety and environmental regulations compliance.
Prove of it is, since 1994 to date we have a zero accident/near accident track of records.
This result comes from our continuous attention to safety/environmental issues which, starting from
personnel hiring, are for us of utmost importance.
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A detailed Risk Assessment will be issued in case we will be the awarded contractor.
Hereinafter are reported our safety statistics.
Year
Hours Worked
2009
2010
2011
2012
2013
55,000
82,000
105,000
95,000
95,000
Number of
accidents/incidents
0 (Zero)
0 (Zero)
0 (Zero)
0 (Zero)
0 (Zero)
Frequency Rate
0 (Zero)
0 (Zero)
0 (Zero)
0 (Zero)
0 (Zero)
Personnel safety performance is regularly monitored.
Awards and prizes are issued on a yearly basis.
11. WORK ORGANIZATION
-
The manpower to be utilized will be about 10 workers: 2 of which are Supervisors (1 of
them will also be responsible for safety supervision) and 8 skilled.
The head office will give all the necessary technical/organizative/logistic supports.
The central point of decision will be in PAZ ASHDOD refinery.
Hereinafter is attached the site organization chart:
Technical Director
Safety - Responsible
Operations - Responsible
Quality Assurance
Workers
12. PREDICTED PERFORMANCES
Altogether, we estimate the overall cleaning time to be the following, for working on a shift basis
and for a sludge volume as specified. We also suppose the tank has no mechanical problems.
Tank No.
400-T-001
Estimated sludge [m3]
5603
Cleaning time [days]
30-35
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Oil recovery
Oil recovery from sludge will be at least 90% of the hydrocarbon portion of the sludge.
The recovered oil will be fully reprocessable.
In particular, water in the recovered oil will be < 0.5% vol.
Size of solid in the oil will be < 20 m.
Normally we achieve BS&W values of < 0.1 % vol.
This is a major advantage of ITW technology, besides stabilization and reuse of hydrocarbons.
Given the optimum quality of the recovered oil, this can be sent directly to a crude tank for
reprocessing or as a fuel oil blending stock.
Water separated from the tank will have the normal composition as per tank drain water and can be
routed in the oily sewage.
Entry conditions
Upon opening manways, the results we will achieve after applying ITW Technology will be:






LEL < 10%
eliminate H2S/mercaptans emissions
No odor/smell shall remain in the tank, which may hamper start of mechanical operations.
H2S = 0 ppm
reduce benzene inside the equipment down to < 1 ppm
eliminate pyrophoric solids problems
Sludge
Sludge left in the tank will consist of heavy/coke-like hydrocarbons/solids, to be removed by
manual cleaning or high pressure water jetting.
It is impossible to predict the amount of sludge which will be left after application of ITW
Technologies, as it depends upon factors which are out of control from both ITW and PAZ
ASHDOD refinery (e.g. tank feed quality and quantity, compatibily issues, previous cleaning
methods, transfer of sludge from other tanks, unforeseen events, etc.).
No value can be therefore be given, but the relative reduction of the initial amount referred to the
hydrocarbon portion of the sludge.
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13. THE FEATURES OF ITW PATENTED CHEMICALS
While the word “chemical” is a very broad one and some companies might claim to have
“chemicals” to clean tanks, we respectfully remind you some of the performances of ITW patented
chemicals.
Tank cleaning
-
Recovered up to 98% of sludge amount, with no problems for reuse/reprocessing.
Recovered up to 95% of sludge amount without any carrier, with no problems for reuse.
Cleaning of tanks in service since 30 years.
Online Cleaning of Production Units
ITW is the only Company worldwide, which possess a technology for cleaning production units
without the need of opening equipment, thereby reducing or eliminating the need for mechanical
cleaning.
This technology has been developed and patented by ITW.
Among the others, we have online cleaned Desalters, Crude Distillation Units, Vacuum Units,
Visbreaker Units, Asphalt Units.
14. SUBCONTRACTING
Depending of specific conditions (e.g. work load), we might subcontract part of the operational job
in order to have local/regional manpower available.
In case subcontracting should be required, previous specific approval from PAZ ASHDOD refinery
will be requested.
In any case, subcontractors will be chosen among PAZ ASHDOD refinery qualified Companies.
15. COMPARISON OF ITW PROCESS WITH COMPETITIVE PROCESSES
ITWs’ strength is the capability of really and definitely minimizing sludge disposal and maximizing
oil recovery (which will be effectively reprocessed without any problems). In this connection ITW
costs and performance are to be compared by taking into account sludge disposal costs and the
value of recovered hydrocarbons, together with the improvements in HS&E.
The ITW process overcomes the drawbacks of the processes actually present in the market.
The core of the ITW process is highly effective chemicals capable of solubilizing per se the sludge.
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This means, the sludge will be solubilized chemically (i.e., stabilized permanently, with no danger
of subsequent precipitation).
In the ITW process, the focal point is to assure the contact of the chemical with all the mass of the
sludge, and this is be achieved by bottom recirculation and/or via washing turbines inserted in the
existing tank manways.
In the past, many chemical formulations have been proposed to clean tank, but not one of them was
effective in those severe cases where the tank has not been cleaned for decades.
ITW chemicals were even able to solubilize fuel oil sludge from tanks not cleaned in over 30 years.
15.1 Manual cleaning
Manual cleaning has been the most used method for cleaning tanks. It has however many
drawbacks in terms of:
 Safety and emissions
 Huge amounts of sludge generated
 Time needed for cleaning
 Danger to personnel entering the tank
 Overall costs
15.2 Cleaning with external rotary nozzles/jet washers (Crude Oil Washing) and use of
centrifuges
In this case, there is a strong mechanical action achieved by rotary nozzles/jet washers usually
placed on the tank roof.
In some cases cold tapping of the roof is necessary to install the equipment.
The sludge is first lifted by mechanical action and then pumped out from the tank.
The method has its limits in the dead zones (area coverage) of this equipment, which cannot cover
all of the tank surface.
Moreover, the hard sludge is not touched by the mechanical action and will be left in the tank for
subsequent manual removal.
Finally, as the sludge is simply suspended in the oil mass, it will precipitate, once the oil+sludge has
been transferred to another tank.
More dangerous is the case when the sludge remains suspended: in this case when reprocessed in a
Production Unit it will create very severe fouling and operating problems. We know of Topping
Units that had to be shut down due to loss of suction of feed pump (following filter clogging),
fouling in the column, and fouling in the preheat train; this resulted in unscheduled turnaround, with
associated loss of production and maintenance costs.
To overcome this problem, some Companies claim to centrifuge the oil out of the tank.
In our opinion, this is not the best solution, in that centrifugation will create lots of sludge to be
disposed of, when the sludge has not been stabilized. This sludge will not be only composed of
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sediments, but also oil+sediments, and the quantity is more likely to be the total amount of the
original sludge. In this case the system is only worthwhile for speeding up the cleaning procedure,
but not for solving the disposal problems.
Moreover, to operate the centrifuge, the inlet oil has to be heated up in order to achieve the
operating viscosity: the heated sludge will therefore simply pass through the centrifuge and will
precipitate again once the oil has cooled down.
In any case, the hard sludge will not be mitigated by the mechanical action and will always be left
inside the tank.
An example will better explain this concept. Oil tankers need to be maintained (dry-docking) each
two years. Before entering the dockyard, they need gas-free certification. For this reason, sludge
from the tank is removed via tank washing machines, according to the COW procedure. Tank
washing machines and COW apparatus are built in the ship, as COW is a standard procedure for oil
tankers. Furthermore, COW procedure is applied at each cargo discharge.
Notwithstanding some major advantages in comparison with aboveground tank, i.e.:




Short time from the last cleaning (two years);
Settling of sludge is not at all favored in the ship (following continuous ship motion);
Sludge suspension with COW machines;
COW procedure applied at each cargo discharge (i.e. in terms of “days” intervals);
after tank cleaning with COW procedures, sludge will remain in tank bottoms, to be removed
manually.
For an oil tanker 100,000 m3 dwt, manually removed sludge can be estimated in the range of 500700 m3.
This can be explained with the following considerations:
 Sludge formation is due to chemical reaction and cannot be reversed by mechanical action
 Sludge is not at all soluble in the crude oil (otherwise it would never be formed, given the
continuous flow of oil in the tank)
 Due to shadow areas, tank washing machines are not 100% effective in sludge suspension
 Hard sludge is not affected at all by mechanical action
We feel, the connection among this example and sludge suspension methods is straightforward.
Please, consider the added crude is not a solvent for the sludge (otherwise no sludge at all would be
formed inside the tank) and serves only to suspend the sludge, at least the easily removable one.
Again, this sludge will be transferred into the receiving tank.
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CONFIDENTIAL
ITW
For your reference, in oil tankers before dry-docking, ITW chemicals were even able to solubilize
and fully recover sludge left in the tank after 3 blank COW washings, i.e. the very hard bottom
sludge.
15.3 Cleaning with robots
Many kinds of robots have been proposed for cleaning the tank.
They are normally hydraulically maneuvered, generally from outside of the tank.
Their main drawback is that they are likely to slip on the sludge layer.
This will impede the robot to effectively work inside of the tank.
Moreover, they cannot be properly operated when the sludge is irregular in height.
Finally, the robots achieve very low flow rates in sludge treatment.
In any case, cleaning with robots has no impact on sludge reuse, but only on sludge extraction (as
an alternative to manual extraction).
15.4 Conventional chemicals
Some Companies claim to use “chemicals” to clean tanks.
Their typical approach is to use emulsifiers in order to bind up with water the free oil out of the
sludge.
Emulsifiers can however emulsify some light oil, but not for sure the sludge or the hard coke-like
material which is typically found in the bottom of a tank.
Additionally, the use of emulsifiers is detrimental because they will remain in the oil phase and
create huge problems for Desalters which malfunction when the crude oil will be reprocessed.
Furthermore, the water which is separated out of the emulsifying process might contain emulsified
hydrocarbons, creating troubles to Waste Water Treatment Plant.
To overcome this additional problem and additional chemical, i.e. a demulsifier, needs to be
injected.
As a final result of the above, conventional chemicals have been indeed unsuccessful in this market;
even worse, in some cases they’ve created additional problems.
15.5 Summary
The following table summarizes some of the key differences of ITW Technology vs the steps of
current technologies.
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CONFIDENTIAL
ITW
STEP
CURRENT TECHNOLOGIES
Suction and centrifugation No real differentiation among
of sludge
hydrocarbons and sludge, which are
pumped together.
Sludge will be therefore transferred
in the receiving tank.
ITW TECHNOLOGY
This operation is not performed and
hydrocarbons
are
chemically
transformed into a fully reusable
product.
Closed loop circulation of No competitors have available ITW
patented,
tailor
made, patented chemicals.
chemicals
Some
emulsifiers/demulsifiers
available in the market have created
more troubles than benefits.
MEG F958M will transform the sludge
into a fully reusable product.
Sludge is stabilized by MEG F958M,
so no subsequent precipitation will
occur.
MEG
F516P
will
remove
hydrocarbons from tank internals and
from residual solids.
Safe entry conditions will be quickly
achieved.
MEG F516P will react with sulphur
compounds and with pyrophorics,
thereby eliminating ignition risks.
Manway
opening
ventilation
During circulation, no airborne
emissions will be generated.
and Delicate and risky phase, due to Safe and environmental friendly
hydrocarbons’ presence in the tank operation, with no risk of pyrophorics
vapour space and pyrophorics ignition and/or noxious emissions.
ignition.
Hydrocarbons in the vapour space
A relevant amount of hydrocarbons have been previously eliminated by
will be left in the tank bottom.
MEG F516P.
VOC emissions.
Maximum environmental protection,
as emissions will be eliminated during
To reduce VOC, costly mobile flares circulation. In any case, a vapor
or adsorbtion methods are to be abatement system can be included in
the provided equipment.
used.
Ventilation requires long downtime. Reduced time for ventilation, which
will be performed by means of
explosion proof ventilators.
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CONFIDENTIAL
STEP
Mechanical cleaning
CURRENT TECHNOLOGIES
Risky operation.
ITW
ITW TECHNOLOGY
Safe operation.
Safe entry conditions might not be Manpower will enter the tank under
achieved, before manpower entry.
safe conditions, such as:
LEL < 1%
Explosivity might still be a problem Benzene < 1ppm
while operating inside the tank and H2S < 1 ppm
personnel may be requested to quit
the tank when LEL > 10%.
No or reduced need for high pressure
water jetting.
High water pressure jetting might
create an ignition danger.
Hydrocarbons will be eliminated
during the circulation phase.
Operations
in
presence
of
hydrocarbons is risky.
No need to work under nitrogen
blanketing.
The case of working in a confined
space under nitrogen blanketing
implies a particular safety concern.
16. ECONOMICS OF ITW TECHNOLOGIES
A simple economic evaluation can highlight the benefits of using ITW technology in comparison
with a conventional sludge suspension process or with manual cleaning.
For ITW process, please calculate that at least 95% of the sludge will be solubilized inside the
tank. Total waste disposal will be lower than 5%.
For sludge suspension process, an overestimated figure is 20% of the sludge “solubilized” inside the
tank; this means, about 80% of the sludge will be separated by filtration/centrifugation. Some of
this sludge will pass through the centrifuge, some will be separated as a waste.
We believe, at least 90% of the original sludge will be disposed of, in one way or another.
Beware: do not consider heated and/or centrifuged sludge as recovered, as it will precipitate out in
the receiving tank!
The heated/centrifuged sludge simply disappears to appear again in the receiving tank: this job is
particularly dangerous for you, in that the sludge out of the cleaning process can be fed directly in a
Production Unit.
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CONFIDENTIAL
ITW
The evaluations in this paragraph do not take into account the following items:





Improved HS&E
Improved tank availability
Reduced Crude oil formation
Reduced burden of waste registers
Reduced burden of the Customer’s personnel to organize waste disposal
We would like to underline, ITW technology also has a tremendous positive impact on HS&E
specifically for the job of cleaning tanks.
As a matter of fact, mechanical/manual cleaning would create several HS&E problems, namely:






VOC emission generation after manways opening
Safety concerns for the operating personnel inside the tank
Sulphur compounds emission generation
Hazards for operating under LEL > 10% conditions
Hazards during manual cleaning (handling of waste, bagging, transportation, etc.)
Waste generation much higher than with ITW technologies
We also underline, ITW technology has a tremendous positive impact on refinery reliability and
energy saving.
As a matter of facts, by processing oil from Tank 400-T-001 without any chemical stabilizing/
demulsifying treatments, e.g. in a Topping Unit, the following problems might arise:
 Water carryover from desalter with increased energy consumption and potential tray damage (in
case a sudden water layer exits desalter)
 Fouling of preheat train with increased energy consumption
 Fouling of downstream plants by solids carryover from desalters (and column bottom)
It is well known, sludge is the least processable oil in terms of stability. Therefore, with an improper
cleaning approach, you might transfer the problem from the tank to the plants.
All of the above HS&E/reliability/energy saving problems will be avoided by utilizing ITW
technologies.
Evaluations
Just to give a quick evaluation of the benefits, we analyze hereinafter the “macro” economics.
We will take into account 5603 m3 of sludge recovery in our cost recovery estimation and a fuel oil
price of 500 Euro/m3.
The value of recovered oil (sludge valorized as Fuel Oil) accounts for:
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CONFIDENTIAL
ITW
5,603 m3 * 500 Euro /m3 = 2,801,500 Euro
The costs of waste disposal (tank sludge is considered as hazardous waste) are accounted for by
considering an overall disposal cost (including transportation, etc.) of about 800 Euro/m3. The
corresponding saving for a total sludge recovery of 5,603 m3 is:
5,603 m3 * 800 Euro/m3 = 4,480,400 Euro
When not recovered, the sludge would have been manually removed, with the connected costs of
manual cleaning to be added.
We rate, when applicable, manual cleaning of tank 400-T-001 would cost at least 500,000 Euro.
Another item to be added to the evaluation is the downtime of the tank, and hence storage capacity
recovery.
A figure to be accounted for could be 0.2 Euro/day/m3 tank capacity.
For a 30,000 m3 tank and for a 30 days cleaning time reduction with ITW technology, the saving is:
0.2 Euro/day/m3 * 30,000 m3 * 30 days = 180,000 Euro
Finally, although not valuable in terms of economic savings, the application of ITW technology
results in much safer and environmental friendly operations for sludge removal, as most of the
operations will be carried out in a closed loop.
We estimate, the positive economic impact of ITW technology will be in excess of 7,500,000 Euro
over mechanical/manual cleaning.
In case of using sludge the suspension/centrifugation approach, the benefits of ITW Technologies
will also include elimination of centrifugation costs.
The evaluation of centrifugation costs should also take into account the sludge that disappears by
heating and the serious dangers following sludge’s presence in downstream operations.
Needless to say, the above are order of magnitude calculations. You will properly calculate the
benefits, according to your real situation.
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PAZAS14 tkcl 401-T-001 crude oil of tec P14_382

Transcription

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