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LABORATORY DISTILALTIONS AND
INTERCONVERSIONS OF DATA
Dr Y.K.SHARMA
INDIAN INSTITUTE OF PETROLEUM
DEHRADUN-248005, INDIA
(AN ISO-9001 R & D INSTITUTE)
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PRINCIPLE OF DISTILLATION
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Distillation
Separation of components from a mixture
due to difference on their volatility.
To concentrate the more volatile component
(mvc) in the vapor phase than in liquid phase
on contact of two phases.
For higher degree of separation columnconsist vertically arranged separation stages.
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Equilibrium Ratio
Distribution of any component of the
mixture of solution between liquid andvapour phase.
Roults law: Relates partial pressure of a
component to its concentration in liquid at
equilibrium
pi
= xi
Pi
(pi
partial pressure of componenti
)
(xi Mole fraction of i in solution)
(Pi VP of i at same temp.)
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Daltons law
pi= yiP(yi mole fraction of component in vapor)
(P total pressure of the system)
Combining these Laws: Mole fraction of
component in vapor/mole fraction of
component in liquid = Ki
Ki= yi/xi= Pi/P
(Phase equilibrium constant at specified
temperature and pressure)
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Economic Significance
DistillationDetermines the capacity of the installations
that provide steam, fuel and cooling water
for the refinery.
Cost of distillation columns accounts 10-12%
of the total investment in process equipment
Total cost of equipment 3 times that of
column alone.
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LAB DISTILLATIONSNon Fractionating
ASTM D-86 Distillation/ASTM D-1160
Raylelgh Vaporisation
Equilibrium Flash Vaporisation (EFV)
Semi Fractionating
Hemple Distillation
VAC Still, Sarnia High / POT Still
Molecular Still / Short Path Distillation
Fractionating Distillation TBP Distillation
Packed Column
Sieve Plate Column (Oldershaw)
Simulated Distillation
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Non fractionating distillations
Liquid mixture is partially vaporized and the
vapor and liquid are allowed to separate
there is an increase of concentration of the
more volatile components in the vapor phase
and the less volatile components in theliquid phase.
Vaporization effected by heating the liquid
or reducing the pressure.
(Degree of separation is not high (ASTM D-86) but may be increased by carrying out theflash (EFV) in number of stages. (e,g Wellhead
separation of gases from crude oil.)
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Distillation cuts in the MM-AEBP plot
Atmospheric Equivalent Boiling Point
MolarMass
ParaffinsC
nH2n-2
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Atmospheric Distillation
ASTM D86/IP123/P18
Apparatus and Operating Conditions
Flask Capacity : 125 ml
Sample Quantity : 100 ml
Condenser Temp. : Depends on fuel
Time for Application of Head IBP: 5-15 min
Av. Rate of Recovery : 4-5ml/min
Time for 95% Rec. to FBP : 3-5 min
No reflux
For gasoline, kerosene and diesel)
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Distillation Characteristics of Petroleum
Products (IP123) (ASTM D86)
Apparatus Assembly using a Gas Burber
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Volatility Characteristics
Typical Distillation Curve for Gasoline
A. Distillation ASTM D86
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ASTM D1160
Completely vaporize under reduced pressure
and gives an idea about the range of higher
fraction
In manual distillation a chain is attached to
the tip of receiver known as anti tip chain.
All these distillations are standardize to TBPdistillation.
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Vacuum Distillation ASTM D1160
Apparatus and Operating Conditions
Flask Capacity : 500 ml
Sample : 200 ml
Distillation Rate : 4-8 ml/min
Coolant Temperature : Depends on sample
Pressure : 4mm/10mm
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DISTILLATION
NON FRACTIONATING SEMI FRACTIONAING FRACTIONATING DISTN
TBP DISTN
BATCH DISTILLAION
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OBJECTIVE
PREPARATION OF FEED STOCK
TO MONITOR & CONTROL QUALITY OFPRODUCT
TO GENERATE YIELD DATA ON %WT/VOL
TO STUDY THE VARIATION OF SOME KEYPROPERTIES THROUGHT OUT DISTN RANGE
DATA IS THE BASIS OF PROPERTY CURVEWHICH CAN BE USED FOR PRODUCTOPTIMIZATION
TO INDICATE WHAT FURTHER PROCESSINGOF TREATING IS REQ TO MEET THEREQUIREMEN OF SPECIFICATION
ASSESSING THE COST OF CRUDE OIL
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TYPES OF COLUMNS
OPEN COLUMNS
BUBBLE TRAY
PERFORATED SEIVE TYPE
PACKED COLUMNS
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PACKING MATERIAL
PRO PACK
HELIX PACK
STEADMAN
CANON PACKING
KNIT WIRE
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Typical TBP Distillation Arrangement
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Average TBP Distillation of Crudes
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Equilibrium Flash Vaporisation
Distillation Curve
A curve of equilibrated vaporized percentage
at different temperatures
Generally determined by correlation methods
Very useful design data for distillation units
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IBP (Initial boiling point) It is comparatively
lower for TBP than ASTM distillation.
IBP of ASTM is lower than Releigh,svaporization. IBP of EFV is highest among
all.
FBP (Final boiling point) Highest for TBPthan ASTM but Releigh,s FBP is higher than
ASTM. FBP is lowest for EFV.
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Typical TBP, ASTM, EFV Curves
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Average Boiling Points
Data Book on HydrocarbonsJ B Maxwell
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Average Boiling Points
Data Book on HydrocarbonsJ B Maxwell
INTERCOVERSIONS OF DISTILLATION DATA
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INTERCOVERSIONS OF DISTILLATION DATA
Reliability of Results
Maxwell Method (Data book on hydrocarbons)
Av. Deviation of converted to experimental 10 to 15F
Admister Method (Applied hydrocarbons thermodynamics)
At atmospheric and higher pressure
ASTM to TBP, Av. Deviation : 7F
TBP to EFV, Av. Deviation : 6F
ASTM to EFV, Av. Deviation : 9F
Under Sub-Atmospheric Pressure
ASTM to EFV, Av. Deviation : 5F
TBP to EFV, Av. Deviation : 6F
ASTM to EFV, Av. Deviation : 6F
E ilib i Fl h V i ti
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Equilibrium Flash Vaporization
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Maxwell Method
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Maxell Method
Interrelationships between empirical cor
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Interrelationships between empirical cor-
relations relating ASTM-TBP-EFV at 760
and 100 m Hg Pressure
Date Book on HydrocarbonsJ B Maxwell (Piromov & Beiswanger)
(i) ASTM D 86 ---- EFV
(ii) TBP ---- EFV
Applied Hydrocarbon TehermodynamicsW C Admister
(Edmister & Pollock)
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TBP Temp. Difference Vs EFV Temp.
Difference
TBP EFV
TBP 50 P t T t V EFV
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TBP 50 Percent Temperature Vs EFV
Percent Temperature
TBP EFV
ASTM 50 P t T t V
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ASTM 50 Percent Temperature Vs
LFV 50 Percent Temperature
ASTM EFV
ASTM T t Diff V EFV
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ASTM Temperature Difference Vs EFV
Temperature Difference
ASTM EFV
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Short Path Distillation
Falling Film Units
Formation of hot spots with overheating and product cracking
Non optimal distillation rates as a
result of formation of laminar films
A high temperature difference in
the product film Vacuum limited to 20 mbars due to
restrictions in vapor flow
Wiped Film, Short Path Evaporator Large free flowing area for vapors
Optimum vipers desing
Optmization of heat transfer and
condction in product films
Smallest hold up
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SPD EVAPORATOR
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SHORT PATH DISTILALTION UNIT
UIC-KDL5 CADI
Technical Data
Throughput : max. 1kg/h
(depending on product)
Evaporator Surface : 4.8 dm2
Condenser Surface : 5.6 dm2
Evaporator Temp. : max. 350C
Working Pressure : down to 0.001 mbar
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Short Path Distillation
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Short Path and Conventional Distillation
Short Path
Distillation
Packed
Column Vac.
Distillation
Operational Mode Continuous Batch
Pressure 10-3mbar 0.05-0.1 bar
Feed Heating Thin Film Reboiler
Heating Duration 10-60 sec. 1-10 hrs
Heated Condensing
Surfaces
1.5-3 cm 50-150 cm
Column packing None Packing
Maximum Cut Point, AET 700C
(1300F)
560C
(1040F)
Separation Principal Kinetic Phase
Equilibrium
SPD RUNS
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SPD RUNS
Digboi Short Reside
Run No. 4 3 11Cut No D 1 2 1 1
Evaporator Temp.C 300 325 300 340
Vacuum mbar 4.16E-2 1.9E-2 4E-2 4.1E-2
Feed Rate g/h 856.8 957.0 924 945.6% Distillate 29.4 44.8 28 44.75
% Residue 70.6 55.2 72 55.25
Sim Dist. Of Distillate C
5% off 486 422 422 -
50% off 566 560 559
95% off 617 624 623
FBP C 633 639 633
SPD RUNS
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SPD RUNS
Kuwait 550C
Run No. 5Cut No. 1 2
Evaporator Temp. C 300 320
Vacuum mbar 1.47E-2 1.45E-2
Feed Rate g/h 564 585
% Distillate 34.0 40.5
% Residue 66.0 59.5
Distillate Sim Dist
5% off - 427
50 % off - 562
95% off - 619
FBP - 629
Boiling Range Distribution by Gas
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Boiling Range Distribution by Gas
Chromatography
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SIMULATED DISTILLATIOND2887
Typical Conditions
Column length 1.2 mLiquid phase OV-1 SE 30, UC-W98
Def. Temp. 350C
Inf. (FID) Temp. 350C
Oven Temp. Ini -30
Final 350C
Oven Temp. Prgo. Rate 10
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THANK YOU