LET THERE

BE OILS!

An Introduction to Crude Oil Distillation. (Technical)

Galindra Mardanny – Senior Process Engineer of PERTAMINA, Indonesia.
 One Do we really need to distill crude oils?

Question
Time matters

• In the origin of oil found in oil pit/marsh, and the utilization is just for combustion, so
it was not needed to distill the oil
• After the invention of Internal Combustion Engine by James Watt (1781 M), it became
the major influence in the rise in the importance of petroleum
– Thus we need to distill it
– Thus we have better engine performance & reliability with distillated oil
– Thus we may earn some money
– Thus we may expand to new markets
– Last but not least,
…we have only 1 (one) EARTH to care
 One Advice

If I can see the far further,

it must be caused of
I’m standing on the shoulder of the giant
(Sir Isaac Newton)
Where do we go
now?
• World goes greener life style in view of people and electricity
• Due to the massive quantity of oil-fueled engines and
machineries, they keep going on and raising
• Gas is more preferred in all sectors
• Coal is just another option…just option 
• Nuclear is preferred for electricity generation due to unmatched
power generation per fuel intake ratio
• Other Renewables Energy is developing…but not yet over-
bubbling
How do we
play last
2015?
• The final energy was majorly
consumed by household,
transportation and
industry…means we still not
green yet 
• Crude oil trading is easy
money…easy come easy go, and
the hands still clean
• Crude oil exploration and
refining crude oil are hard
money…needs stability to
sustain and makes dirty hands
AT LEAST AN A PROGRESS
 Are we ready to
change ourselves
for us?
 Good
Refiner High
Return,
High
Return,
Great Low High
Refiner
Revenue Revenue

Low Low
Return, Return,
Low High
Revenue Revenue
 The problem • Face your problem, don’t go Facebook!

is not the • How come you face your problem if the problem is

problem. your face?

Your attitude • Think different!

to the
problem is
the problem.
 The • The power of center
• The power of small

Partner-in- • The power of many, unity!

Crime
 The Power of Lead / Pb
IV A Elements • Nuclear Reactor Wall

Tin / Sn
• Ligth and Strong

Germanium
• The pioneer of semiconductor

Silicon / Si
• The true army of modern computer

Carbon / C
• Where there is life, there is C involved
The Derivatives
n-paraffin
Paraffinic
Aliphatic iso-paraffin
Cyclic
Hydrocarbon
Benzoid
Aromatic
Polycyclic
 The • CRUDE OILS may be characterized by its PONA
• PONA is Paraffinic, Olephinic, Naphthenic, and

Derivatives Aromatics
• It indicates the major composition of Crude Oil
in Refinery • Can be represented with UOP-Watson K factor

K Factor Type of Hydrocarbon

12.15 – 12.90 Paraffinic
11.50-12.10 Naphthenic-paraffinic
11.00-11.45 Naphthenic
10.50-10.90 Aromatic-naphthenic
10.00-10.45 Aromatic
Ojo cedhak • To have friends with contaminant, then you have just
been contaminated!

kebo gupak
Main
Contaminant

Sulphur Nitrogen

Secondary
Mercaptan Sulfide Bisulfide Primary Amine Tertiary Amine
Amine
RSH RSR RSSR/RSRSR RNH2/RNHR RN
RNH/RNR
 The • Major contaminants to countermeasure are Sulphur,
and Nitrogen
Contaminants • All acidic contaminants can be analyzed as Total Acid
in Refinery Number (TAN)

Define the treating &

catalyst from quality
target

Process Side

Define the Catalyst Life

Contaminants

Define the material class

for process equipment
Mechanical Side
such as piping, vessel, and
pump
These are my natures,
where do you nurture
onto?
• Crude Oils are mixture, not compound.
• Crude Oils are in liquid phase, the components of the
crude oils have different boiling point
• Thus we may separate them by distillation
 Learn the End User Technical
Technical Solar / Diesel Gas Oil / Diesel

terms. Jet Fuel Avtur / Kerosene

Petrol Gasoline

Campus Refinery
Campus Refinery
m3/hour barrel/day

atm, kPa kg/cm2g, bar Cold Reflux Pump-around

Joule/hour MMKCAL/HR Hot Reflux Wash-oil

Furnace Heater/Fired Heater

Standard TP (0C, 1atm) Normal TP (60F, 1bar)

 Crude Oil Fuel Gas

Overhead
Receiver
Crude
Column Sidecut Debutanizer
Stripper
Steam

Kerosene
Crude Distillation Unit Sidecut
Stripper
Steam
Diesel

Desalter
Steam

Reduced
Crude
CDU
Operation
• Driving Force
– Internal
• Relative volatility of each
component to another
components
• High RV goes up, lower RV
down
• Good RV is Good for
separation performance
– External
• The delta pressure between
top and bottom column
CDU
Operation
• Draw Off Temperature
– Regulates T 50% of cuts
• Cold Reflux / Pump-around
– Regulates IBP & T 5% of cuts
• Hot Reflux / Wash-oil
– Regulates EP & T 95% of cuts
 CDU
Operational
Concept
• Why do we use pump around?
• Why do we draw side stream?
• Why do we need stripping steam?
• Why do tray/plate column is more
applied than packed column?
• Why do we use heater-type reboiler?
• Why do we use preheating train?
 Crude Distillation

• Merupakan unit proses terdepan di hampir seluruh

Refineries, sebagai penyedia feed baik langsung
maupun tidak langsung ke proses unit lainnya.
• Oleh karena itu, continuous operation menjadi penting
• Terbagi menjadi Atmospheric Distillation dan
Vaccum distillation.
• Berfungsi untuk memisahkan Crude Oil menjadi
beberapa fraksi minyak berdasarkan perbedaan
rentang titik didihnya.
• Juga menghilangkan sebagian besar salt, sediment dan
juga well-head additif
 Crude Distillation – Preheat Train
• Mensuplai ~55% dari total heat
input yang dibutuhkan untuk
lift dan separasi produk.
• Kuncinya adalah me-maximize
heat transfer dari heat from ke
crude untuk minimize furnace
duty.
• Meminimize penggunaan
cooling utilities (air dan udara)
serta associated equipment
sizing yang dibutuhkan untuk
pendinginan ke kondisi battery
limit.
 Crude Distillation – Desalters
• Single Stage atau Two Stage (aliran air
countercurrent)
• Single, double, atau triple triple
electrical element
• Dibatasi oleh batasan mekanikal serta
karakteristik crude
‒ Temperature
 Conductivity & viscosity
‒ Pressure
 Single Phase (fasa liquid)
• Tipikal kondisi operasi
‒ 105-130ºC
‒ 125 psig-250 psig (9-18 bar)
‒ Ca. 3000 volts per inch jarak antar
electrodes
25
 Crude Distillation – Desalter
• Kegunaan? Crude Oil mengandung:
• Salt hingga 1000 lbs per 1000 barrels minyak (1000 PTB)
• Air
• Solids/Sludge
• Salts dapat:
• Terhidrolisa menjadi HCl  korosi
• Berperan sebagai catalyst dalam pembentukan coke
• Terdeposit sebagai padatan pada permukaan heat exchange  fouling
• Kandungan Salt dalam desalted crude harus kurang dari 2 PTB (pounds
per thousand barrels)
• Air dapat:
‒ Mengurangi effisiensi dapur
‒ Menyebabkan water surge di kolom CDU
‒ Mengurangi kapasitas CDU
• Padatan dapat memnyumbat plug exchangers/piping yang
menyebabkan bekurangnya preheat train efficiency
 Crude Distillation – Desalter

Typical Low Velocity Desalter

Water Injection – Dilution/Dehydration 0.3 vol% air
< 2 PTB salt
Desalter Desalted
Crude Out
0.3 vol% air 5.3 vol% air

Electrodes
Preheat Exchangers
Try
Crude Brine Water Cocks

Mixing Wash Water

Valve
Demulsifier Brine Out
Injection

Alternatif Water Water

Injection Point Injection 5 vol% water

27
 Study Case

•Permasalahan:
‒CDU mengolah 125.000 barrel per hari crude oil
‒Kandungan air di crude 0.8 % vol
‒Efisiensi furnace 85 %
‒Panas penguapan air 500 kcal/kg air
‒Harga fuel adalah 36.75 USD/BSRF (1 BSRF = 1.570.335 kcal)
‒Gross margin kilang adalah 4 USD/bbl crude diolah

Hitung jumlah saving per hari/ per tahun dengan menurunkan

kandungan air di crude menjadi 0.5 % dengan memasang
desalter?
 Crude Distillation – Heaters
Typical Cabin Style Heater
• Heater yang paling penting di
Kilang
• Mempengaruhi seluruh refinery
• Konsumsi energi tinggi
• Crude Heater – 45% of total heat
input
• Operating condition
• Inlet Temperature ~550°F (288°C)
• Outlet Temperature 640°F-735°F
• Outlet Temperature 338°C-390°C
• Coil delta P ~100-150 psi (7-10 bar)

29
 Dasar-Dasar Crude Unit Distillation

Faktor-Faktor yang Mempengaruhi Produk Yield dan Kualitas:

– Komposisi Feed
– Reflux
– Product Draw Rate
– Number of Trays or Packing Height

30
Dasar-Dasar Crude Unit Distillation

• Komposisi Feed
‒ Variability dalam komposisi crude tercermin dalam TBP curves.
 TBP cut ranges merupakan acuan commerical yields BUKAN ASTM
distillation
‒ Crude units sering kali mengolah slop oil yang juga
mempengaruhi kualitas dan yield produk.
‒ Crudes yang diterima oleh Kilang sering kali tidak sesuai benar
dengan crude assay data crude yang bersangkutan.
‒ Umumnya feed ke CDU merupakan campuran dari beberapa
jenis crude dan jarang sekali merupakan satu jenis crude saja.

31
 Dasar-Dasar Crude Unit Distillation

• Reflux
‒ Liquid dingin kontak secara
countercurrent dengan vapor panas
‒ Semakin tinggi reflux, semakin baik
separasi serta recovery dengan
spesifikasi produk yang tertentu.
‒ Semakin besar reflux rate, semakin
besar pula diameter kolom tower
yang besar.
‒ Profil reflux untuk kolom CDU
dipengaruhi oleh profil panas yang
dihilangkan melaui pump around.
Semakin tinggi panas yang
dihilangkan di top, semakin tinggi
internal reflux.

32
 Dasar-Dasar Crude Unit Distillation

• Product Draw Rates

‒ Mempengaruhi internal reflux dan karenanya mempengaruhi end point
produk
‒ Derajat fraksionasi
 Delta temperatur antara 5% volume distilasi fraksi liquid yang lebih berat dan 95%
volume distilasi fraksi liquid yang berdekatan yang lebih ringan.
– Overhead – kerosene 10-17 °C
– Kerosene – diesel 5-10 °C
– Diesel – AGO 0-5 °C

‒ Product cuts (yields) dapat dibandingakan dengan menggunakan delta

antara 50% ASTM boiling point dari produk yang bersangkutan.

33
 Crude Unit Distillation Basics

• Jumlah Stage
‒ Semakin banyak jumlah stage, atau ketinggian kolom packing, semakin
baik separasi.
‒ Overall Overall column efficiency tergantung kepada jumlah stage serta
reflux rate.
‒ Jumlah stage kolom atmospheric distillation umumnya sedikitnya 15 trays
atau sebanyak-banyaknya 50 trays.
‒ Distilasi vakum biasanya menggunakan packing dibagian bottom section
dan trays or packing di bagian top kolom – Penghilangan heat di kolom
vakuum umumnya lebih penting dibanding dengan separasi.
‒ # of stages < # of trays.

34
 Steam Stripping

• Menurunkan partial pressure hydrocarbon karena steam mempunyai

partial pressure sendiri
• Meningkatkan front end of stripped product

Crude Oil Fuel Gas

Overhead
Crude Receiver
Column Sidecut Debutanizer
Stripper
Steam
Kerosene
Sidecut
Stripper
Steam
Diesel

Desalter
Steam
Reduced
Crude
35
 Crude Distillation – Heat Balance

• Distilasi Atmospheric

• Heat Inputs

‒ Heater

‒ Steam

• Heat Outputs

‒ Bottom Product

‒ Side Draws

‒ Overhead Draws

‒ Condenser Duty

‒ Pumparound Duties

36
 Process Variables

• Crude oil properties

• Pressure @ top 0.4-1.1 kg/cm2
• Coil Outlet Temperature 315-425°C
• Top Temperature > water dew point
• Draw Rates
‒ Kerosene 270-290°C
‒ Diesel 290-345°C
‒ Atmospheric gas oil 290-345°C
• Sidecut Stripper Steam Rate IBP Control
• Naphtha Stabilization Control

37
 Reliability Issues

• Operasi Charge Heater

• Korosi pada Overhead
• Naphthenic Acid Corrosion
• Fouling pada Exchanger
Preheat Train

38
 Charge Heater Issues

• Pengendapan Asphaltene
‒ Opportunity crudes Local Hot Spot akibat coking
‒ Crude blending incompatibility
• Pengendapan Salt
‒ Proses desalting yang tidak sempurna
‒ Injeksi caustic
• Oil Film Temperature yang tinggi
‒ High heat flux/low mass velocity design
‒ Outlet temperatures tinggi
• Pengaturan nyala api yang buruk
‒ Perawatan burner jelek
‒ Jaga kandungan O2 levels cukup tinggi untuk
39
mempertahankan agar nyala api jauh dari tube
 Overhead Corrosion Issues

• Pada temperature yang tinggi (> 120°C) reaksi berikut

terjadi:
CaCl2  2H 2O  Ca(OH) 2  2HCl
MgCl 2  2H 2O  Mg (OH) 2  2HCl
NaCl  H 2O  No Reaction
• Pada overhead system (aqueous phase):

Fe  2 HCl  FeCl 2  2 H 
FeCl 2  H 2 S  FeS  2 HCl

Dengan adanya air, HCl mempunyai sifat sangat korosif

40
 Overhead Corrosion Control

Metode Pencegahan Korosi

Penghilangan salt  Desalting

Mencegah hydrolysis  Caustic Addition

Menetralisir HCl  Ammonia/Neutralizer

Protect permukaan  Water Wash/Filmer

Mencegah fasa air  Operasi di atas dew point

 Crude Distillation – Corrosion

Fouling Bubble Cap Tray di Top Kolom CDU

42
 Crude Distillation – Corrosion

Kolom CDU – Korosi pada Distributor

43
 Crude Column Metallurgy
pH Control
Inhibitor

Water Wash
Gas
Naphtha

Sour Water
Steam Carbon Steel
o
< 500 F
Kerosene
> 500oF Carbon Steel
or Monel
Steam
Light Gas Oil 317 SS

Steam Steam
Heavy Gas Oil
Reduced Crude
44
Issue Fouling pada Exchanger

Typical Crude Unit Exchanger Deposits

% by Weight
Iron sulfides, oxides 10-30
Asphaltic material (soluble in benzene) 2-26
Asphaltic material (insoluble in benzene) 41-63
Inorganic salts (CO3=, SO4=, Cl–) 0.5-20

45
 Exchanger Fouling – Primary Causes

• Proses Desalting yang Tidak Efektif

‒ Salts and sediment carryover
• Polimerisasi Radikal Bebas
‒ Oxigen + olefins
• Masalah Spesifik Crude atau Blending
‒ Asphaltines and waxes
‒ High BS+W
• Velocity Crude di HE yang Rendah
‒ < 0.7-1 m/sec

46
 Solusi Mengatasi Exchanger Fouling

• Desalting
‒ Residence time yang cukup
‒ Optimasi pemakaian chemical
‒ Optimasi mix valve pressure drop
• Polimerisasi
‒ Minimize oxigen di wash water
• Crude Blending
‒ Identifikasi permasalahan crude dan operasi dalam limit berdasarkan
assay atau unit testing.
• Exchanger Cleaning
‒ Fouling adalah suatu yang tidak dapat dihindari, oleh karena itu
perlu dimonitor dan dioptimisi. Sparing/isolation exchangers
dibutuhkan untuk online cleaning manual. Spring-type inserts
(seperti Spirelf®) bisa juga digunakan.
47
 How to • Specify the degree of separation:- Set product
specification.

design •
•
Select the operating conditions:- Operating pressure.

Crude
Determine the stage and reflux requirement:- The
number of equilibrium stages.

Column? •
•
Select type of contacting device:- Plates or packing.
Size the column:- Diameter, number of real stages.
• Design the column internals:-
Plates,Distributors,Packing Supports etc.
• Mechanical design:- Vessel and Internal fittings.
 The • On its own unit, CDU is economically-unsustain.
• It will be very sensitive to market price of crude oils and

Refinery is its products.

• For Indonesia case, some of petroleum products the
a complex, prices are controlled by Government.

not just • When the crude price falls, CDU gets some margin.
• When the crude price rises, CDU loses a grand of cash.

single CDU
plant only. • Then, we need bottom conversion and its complete
packages to be
– More sustain economically
– More resistant to market price
– More cash to gain and return
 Typical • CDU – Vacuum Distillation – Hydrocracker & Delayed
Coker
Configuration • CDU – ARHDM & Residue Catalytic Cracker
• CDU – Vacuum Distillation – Fluid Catalytic Cracker

The configuration is also affected by the complex

orientation, such as
a) If gasoline is targeted as the main product, then
RCC/FCC configuration is recommended and proven
better
b) If gas oil is targeted as the main product, the
Hydrocracker configuration is recommended and
proven better
Hydrocracker • Gas oil based products are proven to have more stable
spread of market price
+Delayed • Delayed Coker is the easiest and cheapest way to

Coker
convert from low valuable heavy fraction hydrocarbon
to technically better lighter fraction hydrocarbon

Benefits • Current Hydrocracker mode is MILD Hydrocracker,

which utilizes the reduced pressure ca. 140-150 kg/cm2
g (compared to 1980’s design 180 kg/cm2g)
• The bottom of Hydrocracker can be isomerized and
treated to get best grade of lube base oil product
Residue/Fluid • Gasoline based product is the main consumption of
densely-business cities
Catalytic • R/FCC has its packages to produce highest Octane
Cracker’s Number of gasoline product.

Benefits • R/FCC is the base of more latest technologies

compared to Hydrocracker
• R/FCC is truly total bottom conversion, the heaviest
product is similar to gas oil / diesel but with lowered
grade and used as solvent, not fuel.
 The less
residue
product, the
more
margin
gained
PITAKON
LAN
WANGSULAN

Ngayogjakarto Hadiningrat
Setu Pon,
5 Jumadilakir 1950 Tahun Je
 • Why we need to learn about crude oils?
Why – CRUDE OILS  I’D SO CRUEL  I DO CRUELS

why • Why we learn the crude oil that way?

– CRUDE OILS  COS I’D LURE  COS I’D RULE

and why? • Why we have to master the crude oil’s how-to?

– CRUDE OILS  I’D CO RULES  I DOC RULES
 It’s all about
the money

• Said no oil&gas-businessmen ever!