Desalter

CRUDE UNIT DESALTING Changing Crude and Properties

2nd Middle East Customer Seminar Bahrain June 23rd -25 th , 2008

Overview • What makes a change in crude slate/properties a challenge

• Tank Farm & Desalting – Impa Impact ct & Ma Mana nage geme ment nt

• Wastewater Plant – Impa Impact ct & Ma Mana nage geme ment nt


2

Why is it a Challenge? • Crude characterization u v w x y z

Solids Conductivity Gravity/Viscosity Naphthenic Acids Asphaltenes Metals

• Upstream additives {

Production chemicals Acids Amines Modifiers 2nd Middle East Customer Seminar Bahrain June 23rd -25 th , 2008

3

u Solids • Impact on Tank Farm – Emulsion formation in tankage – Solids settling out in tankage

• Impact on Desalter – Solids stabilized emulsions – Solids settling out in desalter – Oil undercarry

• Tank Farm Solutions – Tank mixers – Chemical additives – Slop blending and pretreatment – Tank design

• Desalter Solutions – Effective mudwash design – Mudwash frequency – Solids wetting aids; enhanced removal agents – Desalter acidification


4

v Crude Conductivity • Impact on Tank Farm – Minimal

• Desalter Solutions – Crude blending is only solution – Rate limitation – Improve transformer

• Impact on Desalter – Shut down of electrical system – Loss of oil-water separation – Oil undercary – Water carryover

1400000

R E T 1200000 E M / S N 1000000 E M I S 800000 O C I P 600000 Y T I V I 400000 T C U D 200000 N O C

20% DOBA IN ARAB HVY 10% DOBA IN ARAB HVY

DOBA ARAB HVY

0

0

10

20

30

40

50

60

70

80

90

100

TEMPERATURE oC


5

w Gravity/Viscosity • Impact on Tank Farm – Tank stratification – Poor water removal Increase rates

Acidification Program

• Impact on Desalter – Reduction in capacity – Oil undercarry – Water carryover

• Tank Farm Solutions – – – –

Tank mixers Crude blending Diluents Pre-treat with demulsifiers – Slop blending and pretreatment

• Desalter Solutions – – – –

Increase wash water Increase temperature Demulsifier selection Desalter acidification


6

x Metals

• Impact on Tank Farm – Minimal

• Desalter Solutions • Impact on Desalter – Minimal except when bound with other constituents • Ca-naphthenate • Na-naphthenate • FeS

– Oil undercarry – Water carryover – Emulsion stabilization

– – – –

Increase wash water Increase mixing Desalter acidification Metals removal additives • EC2483A (proprietary technology)


7

y Asphaltene Incompatibility • Impact on Tank Farm – Poor water removal – Emulsion formation in tankage

Asphaltenes

• Tank Farm Solutions – Tank mixers – Crude blending – Pre-treat with asphaltene stabilizers – Slop blending and pretreatment

• Desalter Solutions

• • Impact on Desalter – Reduction in capacity – Emulsion in desalter – Oil undercarry

– – – –

Increase wash water Increase temperature Increase mixing Treat with asphaltene stabilizers


8

z Naphthenic Acids • Impact on Tank Farm – Poor water removal – Emulsion formation in tankage

• Impact on Desalter – – – –

Emulsion in desalter Low pH brine (if acid treated) Oil undercarry Water carryover

• Tank Farm Solutions – Tank mixers – Crude blending – Tankage dehydration additives – Slop blending and pretreatment

• Desalter Solutions – – – –

Increase wash water Increase temperature Increase mixing Demulsifier selection


9

{ Upstream Additives Additive

Applications

Impact Crude Unit Process

Mineral acids (HCl, HBr, KCl, H3PO4, HF)

Well Stimulation, Emulsion Breaking, Scale Control

Yes - corrosion, fouling

Organic Acids (Formic, Acetic, Citric, Glycolic)

Well Stimulation, Completion Fluids, Emulsion Breaking

Yes - corrosion, fouling

Other acids (alcoholic HCl, EDTA, Fluroboric acid)

Well Stimulation, Completion Fluids, Scale Control

Yes - corrosion

Gelling Polymers

Well stimulation, Completion Fluids

No

Quantanary Amine Chloride salts

Corrosion Control, Biocide

Potentially

Oxyalkylate resins

Emulsion Breaking

No


10

{ Upstream Additives Impact Crude Unit Process

Additive

Applications

Solvents

Paraffin control

Some (chlorinated solvents)

Water treating polymers

Emulsion Breaking

Low probability (water- based)

Metal salts (ZnCl2, AlCl2, poly(aluminum) chloride)

Emulsion Breaking

Yes - corrosion

Poyldimethylsiloxane, Fluorosilicones

Antifoam

Crude unit no; Potentially hydroprocessing units

Methanol

Hydrate Inhibitor

No; Will impact waste plant

Phosphate esters, Phosphonates

Scale Control, Corrosion Control

Yes – corrosion, fouling

Acrylic acids

Scale Control

Yes - corrosion


11

{ Upstream Additives Additive

Applications

Impact Crude Unit Process

Filming Amines (polysubstituted monoamines, Diamines, Polyamines, Imidazoline)

Corrosion Control

Potentially

Chlorine, Bromine

Biocide

Yes

Ethylene Vinyl acetate Copolymers, Styrene/Ester Copolymer

Wax crystal modifiers

Some (chlorinated versions)

Neutralizing Amines (MEA, EDA, MMA)

Corrosion Control, H2S Scavenger

Yes

Triazines

H2S Scavenger

Yes

Polyalphaolefin polymers

Drag reducers

No


12

Prescreening Methods • Updated Assays • Spec’s on crude – Buyers and put restrictions or request notification

• Analytical testing upon arrival – Routine • • • •

Salts BS&W Filterable solids TAN

– Non-routine • • • •

Blending study Amines Acids Portable Electrical Desalter

• Mechanical – Survey/Audit the capabilities of the Tank Farm, Desalter, and Wastewater Plant

• Operationally – Develop flexibility to handle challenge crude properties


13

Wastewater Plant Impact & Management Desalter’s, Tank Farm, Slop Oil Tanks......... • All contribute to the WWTP influent • Any change in the above will impact WW plant • The Biological section (bacteria) of the refinery can take many days to “respond” to the change/overcharge of the contaminants • RESULTà effluent out of spec, penalties/legal actions, space in buffer tk’s for the un-treated fluids etc. 2nd Middle East Customer Seminar Bahrain June 23rd -25 th , 2008

14

WWTP Schematic High Oil and Grease

High Solids

High COD

High Organic Acids

High Amines

DAF Equal.

2ndry

Biox

API

Clarifier DAF

High Oil and Grease

Recycle

Effluent Hg , Se, Metals

Waste To Belt Press

Waste To Centrifuge

High Solids


Change of crudes Impacts on WWTP W W TP M a in I m p a ct A r e a a n d Bottlenecks

Issues High Solids Loading

Primary Treatment, Dewatering, Incineration

High Oil and Grease Loading

Primary Treatment, Secondary Treatment, Sludge Dewatering

High COD

Secondary Treatment and Clarification

Metals: Hg, Se, Ca

Organic Acids

Environmental Permit Compliance

Secondary Treatment

Amines, Ammonia

Secondary Treatment, Environmental Permit Compliance


Solutions I ssu es

S o l u t i o n s – En g i n e e r e d P r o c e s s e s

High Solids Loading

Solids Management Audit, Chemical Selection

High Oil and Grease Loading

Lab Simulation, Oil Recovery Management, Chemical Selection

High COD

Lab Biox Modeling, Bioaugmentation, Upset Recovery Program

Metals: Hg, Se, Ca

Opportunity Crude Assessment, Metals Removal Chemical Additives

Organic Acids

Lab Biox Modeling, Bioaugmentation, Upset Recovery Program

Amines, Ammonia

Lab Biox Modeling, Bioaugmentation, Upset Recovery Program 2nd Middle East Customer Seminar Bahrain June 23rd -25 th , 2008

Solutions – Primary Treatment • Equipment/facilities review • Equipment optimization – Increase containment volume – Control parameters (rates, pH, etc.)

• Coagulant/flocculant programs – Improved reverse emulsion breakers (Inorganic blends) – High efficient flocculants – Automation

Additives

• Upstream treatment – Slop – Desalter – Tank dewatering

DAF P r o c e s s Effluent

Equal.

API DAF


Solutions - Secondary Treatment (BIOX) and Clarification • Equipment/facilities review • Develop Upset recovery/maintenance programs • Non Routine Testing – Respirometry

• Chemical Application Programs – – – – –

Antifoams Bioaugmentation Nitrifiers Coagulants/Flocculants Metal Removal Additives

Antifoams, Bioaugmentation, Polymers

API

2ndry Clarifier

Biox Recycle


“The Surprise Amine”

Example of a change in crude slate and its impact

What Normally Happens ? Crude tower corrodes due to build up of amine chloride salts and hydrotreater feed/effluent exchangers foul from ammonia chloride salts; only warning is the reduction in ovhd neutralizer demand and build up of pressure drop in exchangers Desalt Aid Refinery Tank Farm Desalter

Brine

Atmospheric Tower

WWTP

Wastewater biological system responds by going offspec on discharge parameters

H2S Scavenger

Terminals

H2S Scavenger is added without knowledge of Refiner 2nd Middle East Customer Seminar Bahrain June 23rd -25 th , 2008

21

What Could Happen? Crude tower monitors for the potential of corrosion by testing naphtha, diesel, and kero for chlorides; mitigation strategies are implemented: • Reduce crude in crude slate • Monitor salt formation potential • Insure HDS water wash is operating; water draws are monitored for chloridesDesalt Aid Refinery Tank Farm Desalter

Brine

Crude is isolated in a tank and rated to the crude unit at a safe rate

Atmospheric Tower

WWTP

Wastewater monitors the level of the amine in the influent water; mitigation strategies are implemented: • Because of earlier WWTP system audit and Respirometer studies the biological system is augmented with nitrifiers

Terminals

H2S Scavenger is added with knowledge of Refiner 2nd Middle East Customer Seminar Bahrain June 23rd -25 th , 2008

22

Summary • There are many different containments and crude characteristics that can have a negative impact on a Refinery • Proactive determination of a refinery limitations and development of a mitigation strategy can minimize impacts • The management of changes in crude slate starting at the Tank Farm and Desalting Operation can minimize downstream impacts • Opportunity crude’s potential impact on Wastewater Plants can be also managed successfully • Communication & Collaboration is the key


Desalter

Recommend Documents