Project Report in GAIL(India) Limited_Prakash

ANALYSIS OF PROPANE REFRIGERATION UNIT
AND STUDY OF NAPHTHA LOSSES AT LOADING
GANTRY
Vijaipur, Guna (M.P)
Mr. Vinay Patni, Prakash Chand Baliwal,
Sr. Manager (GPU-OPS) Institute Of Technology, Guru
Ghasidas(Central) University,Bilaspur

2 | Analysis Of Propane Refrigeration Unit And Study Of Naphtha Losses At Loading Gantry
Certificate
This is to certify that PRAKASH CHAND BALIWAL student of B.Tech in Chemical
Engineering at INSTITUTE OF TECHNOLOGY, GURU GHASIDAS(CENTRAL)
UNIVERSITY, BILASPUR, has successfully completed training in Gas Processing
Unit(GPU),Department at GAIL (India) Limited, Vijaipur from 20th
June to 21th
July.
He has successfully completed the project entitled, “ANALYSIS OF PROPANE
REFRIGERATION UNIT AND STUDY OF NAPHTHA LOSSES AT LOADING GANTRY”
under the guidance of Mr. K.V.S. Rao, DGM (GPU-OPS) and Mr. Vinay Patni, Sr.
Manager, (GPU-OPS), GAIL (India) Ltd.
His conduct and behavior during the Vocational training period was found to be
exemplary.
Mr. K. V. S Rao, Mr. Vinay Patni,
DGM (GPU-OPS), Sr. Manager, (GPU - OPS)
GAIL (India) Ltd. GAIL (India) Ltd.

Abstract
The following report describes an overview of the outcomes of work undertaken
by me during the industrial training in GAIL (India), Vijaipur. During this training the
LPG extraction process from natural gas, taking place in this plant was studied. All
the modules constituting the plant including the offsite were visited and the
operation involved was learnt from the plant officials. The placement of equipment
and utilities were analyzed in terms of feasibility and economics. The usage and
working of different type of valves and pumps at specific locations were also learnt.
Training at Fire & Safety department was given, where we were introduced with all
Do’s and Don’ts.
A project based of calculation of the tons of refrigeration of both the phases of the
plant which consisted of heat rejected/absorbed by evaporators and condensers
and the work done by compressors. I also undertook the study of naphtha leakage
at the loading gantry in which I plotted a Temperature v/s Losses curve to indicate
the feasible atmospheric conditions to minimize the losses.

Acknowledgement
No work can be completed successfully unless the path of wisdom is illuminated by
the luminous and excellent guidance. Dozens of persons have aided by devoting
their help in preparing this project report.
I would like to express my gratitude to all those who gave me the possibility to
complete this project work. I want to thank the Department of Chemical
engineering, of my institution for giving me the permission to commence this
project in the first instance.
I am deeply indebted to my guide Mr. K.V.S. Rao (DGM, GPU-OPS) and Mr. Vinay
Patni (Senior Manager, GPU-OPS), GAIL (India) Ltd, Vijaipur, whose help,
stimulating suggestions and encouragement helped me in all the time of our
project work.
Also, I extend my sincere thanks to Mr. Lovejit Singh and Mr. Hara Gopal Gadi for
their constant interaction, help, valuable suggestions and support during my
project period.

Index
Title Page No.
Chapter -1
Introduction
 About GAIL
 GAIL's Business Portfolio
 GAIL, Vijaipur Plant
 Process Description
 Offsites
6
Chapter – 2
Overview of Project
 Refrigeration
 Tons of Refrigeration
 Propane Refrigeration Unit
 Naphtha
 Naphtha Loading
20
Chapter – 3
Calculations
27
Chapter – 4
Results and Discussions
36
Chapter – 5
Conclusion
39
References 40
List of Tables 41
List of Figures 42
List of Photographs 43

Chapter - 1
Introduction
1.1 About GAIL:
GAIL (India) Limited, is India's flagship Natural Gas company, integrating all aspects
of the Natural Gas value chain including Exploration & Production, Processing,
Transmission, Distribution and Marketing and its related services. Now it is
spearheading the move to a new era of clean fuel industrialisation, creating a
quadrilateral of green energy corridors that connect major consumption centres in
India with major gas fields, LNG terminals and other cross border gas sourcing
points.
1.2 GAIL's Business Portfolio includes:
 7,700 km of Natural Gas high pressure trunk pipeline with a capacity to carry
157 MMSCMD of natural gas across the country
 7 LPG Gas Processing Units to produce 1.2 MMTPA of LPG and other liquid
hydrocarbons
 North India's only gas based integrated Petrochemical complex at Pata with
a capacity of producing 4,10,000 TPA of Polymers
 1,922 km of LPG Transmission pipeline network with a capacity to transport
3.8 MMTPA of LPG
 27 oil and gas Exploration blocks and 3 Coal Bed Methane Blocks
 13,000 km of OFC network offering highly dependable band with for telecom
service providers
 Joint venture companies in Delhi, Mumbai, Hyderabad, Kanpur, Agra,
Lucknow, Bhopal, Agartala and Pune, for supplying Piped Natural Gas (PNG)
to households and commercial users, and Compressed Natural Gas (CNG) to
the transport sector

IPCL o
HAZIRA
VIJAIPUR
VAGHODIA
o JALALPURA
o SANDWATA
KASARBADI o
JHABUADUDHMAL o
DEVGARHBARIAo
o SHERPURA
LPG PLANT
o VEMAR
JHAGADIYAo
o SAMNI
KHERA
MOHANKOT o
o JAMBUDI
o KACHACHIBARODA
JAGOTI o
GORKHPURA o
JAISINGHPURA o
DHATARWADA o
MANAGEMENT CONTROL CENTRE LPG PLANT
DESU
AURAIYA
SONIPAT SIWALI
BAHADURGARH
G’ BAD
DADRI
o
KARANPUR
BAJHERAo
o FARIDABAD
o
N
AW
A
D
IA
GURGAON o
SHAHJAHANPUR o
o
PIPRAULA
oSACHENDI
o MATHURA
SCHEMATIC DIAGRAM OF HVJ/GREP/DV PIPELINE
AGRACGS
FIROZABAD
DAHEJ
MAKARWAN o
ANTAo
CHHABRAo
ATTRU o
o BORERI
o CFCL G’PAN
SAMACORE
o BAJRANGGARH
o NAISARAI
o KAMAD
o PIRONTH
o KHERI
o BHAUNTI
DUNGARWAHAo
o CHITARA
MIANPUR o
o KHARAUWA
o GORABHUPKA
oACHALGANJ
oMAURWAN
oTHULENDI
JETHWADAo
LPG PLANT
NTPC
INDOGULF
o JAGDISHPUR
o PHULPUR
IFFCO
NARAYANPURo
oMALAKPUR
JIGNIS o
BANDHMAU o
CHAINSAo
o BABRALA
TCL
o
MUNDER
KSFL
o AONLA
IFFCO
NTPC
IOCL
SKBAD
o KHORDAR
o BURDHA
o MARA
o SONE KAGURJA
BAMNIKALAN o
o SIHANA
o JATAULI
SBAD
o S’WASA
MARUTI
IGL
NTPC
NTPC
UPPC PATA
HVJ P/L
DV P/L
GREP P/L
COMP. STN.
LPG PLANT
RR/IP/SV STN.
CONSUMERS
LEGEND
NGMC
NOIDA
KOSAMBAo
o
A
N
K
O
T
VAGHODIAo
o
o MALANPUR
KELARAS o
o GWALIOR
o
KMPL 12”x 72KMS
NFL o
CONSUMERS
SFCL KOTA
VKPL (18’’X140 KMS.)
o IBRAHIMPUR
DHAULPUR o
IDPL 10”x33 KMS
RRVNL
DEWAS
PITHAMPUR
JIPPL 16”x92 KMS
o INDORE
12”x 32 KMS

 Participating stake in the Dahej LNG Terminal and the upcoming Kochi LNG
Terminal in Kerala
 GAIL has been entrusted with the responsibility of reviving the LNG terminal
at Dabhol as well as sourcing LNG
 GAIL Gas Limited, a wholly owned subsidiary of GAIL (India) Limited, was
incorporated on May 27, 2008 for the smooth implementation of City Gas
Distribution (CGD) projects. GAIL Gas Limited is a limited company under the
Companies Act, 1956
 Established presence in the CNG and City Gas sectors in Egypt through equity
participation in three Egyptian companies: Fayum Gas Company SAE, Shell
CNG SAE and National Gas Company SAE
 Stake in China Gas Holding to explore opportunities in the CNG sector in
mainland China
 A wholly-owned subsidiary company GAIL Global (Singapore) Pte Ltd in
Singapore
1.3 GAIL, Vijaipur Plant:

Fig 1.1 Layout of Gas Processing Unit (GPU)
Gail have its first LPG plant at Vijaipur .In this plant LPG is extracted from natural
gas by following latest Turbo expander process .The design gas processing capacity
of the plant is 15 million standard cubic meters of gas per day (mmscmd) with
annual LPG production capacity being 4,06,000 million tons. The other products
that are recovered in the process are propane, pentane and naphtha
Commissioning Dates
 LPG train-11 (phase-I) - Feb 11, 1991
 LPG train -12 (phase-II) - Feb 11,1992
Steps Involved
 Gas receiving ,drying and regeneration
 Pre-cooling and chill down in expander
 Distillation
1.4 Process Description:
LPG recovery facility of each plant is designed to handle 7.5 mmscmd of gas. The
natural gas is received from HVJ pipeline to recover LPG, propane, pentane and
SBPS (Special Boiling Point Spirit). Feed gas from HVJ pipeline compressor station
is presently available at 53.5 kg/cm2
abs at temperature of 31 o
C.
 Gas Receiving ,Drying And Regeneration
 The natural gas coming from HVJ pipeline flows through a knock out
drum (KOD), where the liquid present in gas is knocked off

 From the knock out drum it goes to drier (one operating + one
regeneration) having molecular sieve (Zeolite, size 4A) where the
moisture content reduces from 81 kg/mmscmd to1 kg/mmscmd

Fig 1.2 Process Flow Diagram TR-12

 Pre Cooling And Chill Down In Expander
 This dried gas is then passed through the feed gas chiller (based on
Linde’s principle) and where the temperature of gas reduce to -39o
C and
some amount of gas converted to liquid or condensate
 The partially condensate gas is then passed through the separator 1
where the gas and the condensate are separated
 As the whole amount of gas is not condensate so it is required to reduce
the temperature of gas further lower than -39o
C. The gas from the
separator 1 is fed to expander-compressor where the gases are allowed
to expand isentropically (adiabatically and reversibly) as result of
expansion process heat is released and temperature further reduced
from -39o
C to -70o
C
 Distillation
LEF COLUMN
 The condensate liquid is then separated in separator 2 and the liquid and
gas from separator 2 is first used as cooling media in the chiller and the
liquid is fed to LEF (light end fractionation column) and the gas is used to
provide cooling in the LEF column condenser
 The light hydro carbon (CH4) and CO2, N2 are separated as the top product
in LEF column and the remaining hydrocarbon are taken as bottom
product
PROPANE COLUMN
 The bottom product hydrocarbon is then fed to propane column (Sieve
or valve tray column) where propane is recovered as the top product
and sent to propane storage tanks

GAS COMPRESSOR STATION CENTRALLIZED PIPELINE MAINT. BASE
LPG PHASE 1(TRAIN 11) LPG PHASE 2 (TRAIN 12)

LPG COLUMN
 The bottom product from the propane column is fed to LPG column
which is packed bed column, and packing material used is of pall rings.
 When the LPG (50:50) by wt. of propane and butane are recovered as the
top product and the bottom product is called natural gasoline (NGL)
SBPS COLUMN
 The NGL from LPG column is fed to SBPS column where pentane is
separated as product and SBPS is extracted as bottom product
 The LEF O/H gases are heated in regeneration gas heater and used for
regeneration of drier. The gases used as regeneration and remaining LEF
O/H gases are called lean gases and are sent to HVJ after compressing as
HP gas at 56 Kg/cm2
and MP gas at 46 Kg/cm2
1.5 Offsite:
The central utilities of factory consist of following:
 Raw water, Service Water, Fire Water, Cooling Water, Drinking Water
Water is required to meet the cooling water makeup, service
water and drinking water requirements. The raw water system
consists of a raw water reservoir, raw water treatment plant and
filtered water reservoir. This raw is stored in two raw water reservoir
having a capacity of 62500 m3
.

Service water is supplied to LPG unit from offsite area at a
pressure of 7.5 kg/cm2
a through a 2” header. Service water is made
available at various hose stations.
 Compressed air system
A 3” instrument air header supplies instrument air to the unit at
a pressure of 7.5 kg/cm2
a. A block valve with a blind is provided at the
battery limit. A pressure gauge indicates the pressure of instrument
air to the unit. The various instrument air tapping are taken off this
header. The header is provided with a low pressure alarm. Maximum
requirement of Instrument Air is estimated at 400 NM3
/hr for LPG unit
with offsite. Plant air is supplied to the unit at various hose stations
through a 2” header at a pressure of 7.0 kg/cm2
a.
 Inert gas system
Inert gas is supplied to the unit at a pressure of 9.0 kg/cm2
a.
Inert gas is produced by combustion of fuel gas in an inert gas
generator. This is coupled with a drying unit in the offsites. Inert gas
of the following specifications shall be supplied to the plant.
i) Dew Point @ 9.0 kg/cm2
a, °C : -40
ii) Temperature at B/L,°C, Nor : 40 °C
iii) Composition

Component Volume, %
H2 0.1 (max.)
O2 0.5 (max.)
CO 0.1 (max.)
CO2& N2 Balance
Oil content Oil free
Inert gas is made available at the various hose stations and for
blanketing of V-108 (Hot Water Expansion Vessel). It is also used for
purging of distance piece of reciprocating compressors.
 Steam and soft water system
Soft water is used in the LPG Unit for hot water system make
up, Residue Gas Compressor jacket cooling make up. The soft water is
supplied from offsite through a 2” line at a pressure of 9.5 kg/cm2
a.
Soft water header is provided with a flow indicator. Pressure gauge is
also provided on the header.
 Product storage and transfer
LPG form LPG recovery plant is received via 6’’ Pipeline and
stored in the LPG spheres. The spheres are of nominal capacity 2200m3
each. Normal storage pressure is 10.5 kg/cm2
corresponding to a
temperature of 450
C. The spheres are insulated for fire protection and

are also provided with spray water connection in order to keep the
surface cool in case of fire in the adjoining area.
Following facilities exist for storage of the products:
(a) LPG - Eight Spheres of 2575 M3
water capacity
each
(b) Propane - Three Spheres of 2575 M3
water capacity each
(c) Pentane - Five Bullets of 198 M3
water capacity each
(d) NAPHTHA - Two Tanks of 1300 M3
water capacity each
 Product loading and dispatch system
Following facilities exist for loading & dispatch of the products
A loading control room monitors and records all the loading
operations which are taking place at rail and road gentries. This control
room is also provided with fire and safety panels where all the
indications from gas detectors located around the loading are
monitored:
(a) LPG - (i) Rail Loading Gantry with Eighty loading points
(ii) Road Loading Gantry with Eight loading bays
(b) Propane - Road Loading Gantry with Four loading bays
(c) Pentane - Road Loading Gantry with Two loading bays
(d) NAPHTHA - Road Loading Gantry with Three loading bays
 Chemical storage and distribution
The chemical used in LPG recovery unit is Methanol. Methanol
is used as antifreeze agent whenever ice or hydrate formation is likely
to take place. Methanol requirement arises mainly during plant

startup and during times when there is ingress of moisture into the
system. Methanol dissolves ice/hydrate and comes out of the system
along with the heavies.
Methanol from offsite storage is received in the methanol pot.
Methanol pot is 2.2 m OD and 4.4 m height vertical vessel of carbon
steel construction. The vessel is blanketed with inert gas at a pressure
of 1.05 kg/cm2
a through pressure regulator and discharge pressure of
61 kg/cm2
a. The vessel is provided with a pressure cum vacuum relief
valve. For safety against high pressure 2” rupture disc is provided.
Methanol from the condensate pot is pumped to the methanol supply
header of LPG plant by methanol injection pumps. Methanol from the
supply header is injected at various locations throughout the unit,
whenever it is required.
 Flare system
The discharge from various safety valves, control valves and
pump casing vents in the unit are collected in the 24” flare header
which flows to flare K.O. drum with a slope of 1:500. The normal
operating pressure is 1.5 kg/cm2
a but this may go to 4.5 kg/cm2
a
during peak flaring. Flare K.O. drum is 3.2 m OD and about 12 m long
horizontal vessel of carbon steel construction. Flare gases from K.O.
drum outlet are routed through a 30” line to 30” flare header for the
LPG plant. Flare K.O. Drum is provided with a high level alarm. Flare
header is provided with a fuel gas purge connection at the dead end

of the header in LPG Unit. The 12” header is provided with a fuel gas
purge connection at the dead ends of the header in Propane area. The
flow of fuel gas is regulated by restriction orifice. Excessive flaring of
hot gases is to be followed by higher purge rates of fuel gas to avoid
flare header developing vacuum. High fuel gas purge rates are
obtained through HCV, which is used after high flaring.
 Effluent Water treatment system
The effluent treatment plant attached to the LPG Recovery
Plant is designed to receive and treat four types of effluents generated
from the phase-I and phase-II plants. During the treatment process
two main types of byproducts are generated from all effluents, viz slop
oil and sludge which are collected in separate circuits and disposed off
to the assigned areas. The treated and filtered water devoid of
suspended solids, oil, BOD etc. is collected and stored in guard ponds.
From these ponds treated water is released after monitoring the
effluent quality conforming to the standards.

Chapter – 2
Overview of the Project
2.1 Refrigeration:
The transfer of heat from a low-temperature region to a high-temperature one
requires special devices called refrigerators. Refrigerators are cyclic devices, and
the working fluids used in the refrigeration cycles are called refrigerants. A
refrigerator is shown schematically in Fig. 2.1. Here QL is the magnitude of the heat
removed from the refrigerated space at temperature TL, QH is the magnitude of the
heat rejected to the warm space at temperature TH, and Wnet, in is the net work
input to the refrigerator.
Fig 2.1 A schematic refrigerator
Warm
Environment
Cold Refrigerated
Space
W net, in
R
QH
QL

2.2 Tons of refrigeration:
The capacity of a refrigeration system that can freeze 1 ton (2000 lbm) of liquid
water at 0°C (32°F) into ice at 0°C in 24 h is said to be 1 ton. One ton of
refrigeration is equivalent to 211 kJ/min or 200 Btu/min. The cooling load of a
typical 200-m2
residence is in the 3-ton (10-kW) range.
2.3 Propane Refrigeration Unit:
Fig 2.2 Schematic of Propane Refrigeration Unit

The above system is a refigeration cycle comprising of three main components
viz. Evaporator, Condensor and Compressor.
The nomenclature of the vessels are as follows-
1. V -123 Propane Refrigerant Accumulator
2. V-124 Propane I-Stage Suction K.0. Drum
3. V-125 Propane II Stage Suction K.O. Drum
4. V-126 Propane Refrigerant Flash Pot
5. E-125 Propane Condenser
6. E-126 LEF Condenser-2
Propane refrigeration system has been provided to supply refrigeration in LEF
condenser of LEF column and feed gas chiller in combination recovery mode of
operation, this system operate in close cycle with, make-up, two stage refrigeration
system is provided. The 1st
stage of system is at 1.2kg/cm2
pressure and -37.6 0
C
temperature. The 2nd
stage is at 4.41 kg/cm2
a pressure and -2.29 0
C temperature.
The second state is economizer stage with no process load and is meant to reduce
energy consumption of the system
Propane being compressed by Propane refrigeration compressor is condensed in
Propane condenser and taken to accumulator. Form accumulator the refrigerant
is taken to 2nd
stage suction K.O. drum where it is flashed. Vapor from this drum
are taken to 2nd
stage compressor suction where they are mixed with 1st
stage
discharge vapors. Liquid from 2nd
stage suction K.O. drum are taken to LEF
condenser-2 and cold box to supply refrigeration duty.
Vapors generated in heat exchangers are taken to 1st
stage suction K.O drum,
vapors from V-124 go to the 1st
stage compressor suction. The compressor is
centrifugal type by gas turbine and is suitable to handle either propane or
propylene refrigerant.
It should be noted that propylene refrigerant shall not be available since PP/PDH
project execution has been deferred by GAIL. Hence propane instead of propylene
refrigerant shall be used as refrigerant for combination recovery mode of operation
in the LPG plant.
2.4 Naptha:

Naphtha is a liquid petroleum product that boils from about 30°C (86°F) to
approximately 200°C (392°F), although there are different grades of naphtha within
this extensive boiling range that have different boiling ranges. The term petroleum
solvent is often used synonymously with naphtha. On a chemical basis, naphtha is
difficult to define precisely because it can contain varying amounts of its
constituents (paraffins, naphthenes, aromatics, and olefins) in different
proportions, in addition to the potential isomers of the paraffins that exist in the
naphtha boiling range (Tables 2.1). Naphtha is also represented as having a boiling
range and carbon number similar to those of gasoline, being a precursor to
gasoline. The so-called petroleum ether solvents are specific-boiling-range naphtha
as is ligroin. Thus the term petroleum solvent describes special liquid hydrocarbon
fractions obtained from naphtha and used in industrial processes and formulations.
Product Lower
Carbon
limit
UPPER
Carbon
limit
Lower
Boiling
Point (in
o
C)
Upper
Boiling
Point (in
o
C)
Refinary Gas C1 C4 -161 -1
Liquefied
petroleum gas
C3 C4 -42 -1
Naphtha C5 C17 36 302
Gasoline C4 C12 -1 216
Kerosene/diesel
fuel
C8 C18 126 258
Aviation
turbine fuel
C8 C16 126 287
Fuel oil C12 >C20 216 421
Lubricating oil >C20 >343
Wax C17 >C20 302 >343
Asphalt >C20 >343
Coke >C50 >1000
Table 2.1 General Summary of Product Types and Distillation Range
 Hazards Identification:
 Emergency Overview

Regulatory status : This material is considered hazardous by the
Occupational Safety and Health Administration (OSHA) Hazard
Communication Standard (29 CFR 1910.1200
Hazard Summary : Extremely flammable. Irritating to eyes and
respiratory system. Affects central nervous system. Harmful or fatal if
swallowed. Aspiration Hazard.
 Potential Health Effects
Eyes : High vapor concentration or contact may cause irritation and
discomfort.
Skin : Brief contact may cause slight irritation. Skin irritation leading to
dermatitis may occur upon prolonged or repeated contact. Can be
absorbed through skin.
Ingestion : Aspiration hazard if liquid is inhaled into lungs, particularly
from vomiting after ingestion. Aspiration may result in chemical
pneumonia, severe lung damage, respiratory failure and even death.
Inhalation : Vapors or mists from this material can irritate the nose,
throat, and lungs, and can cause signs and symptoms of central
nervous system depression, depending on the concentration and
duration of exposure. Inhalation of high concentrations may cause
central nervous system depression such as dizziness drowsiness,
headache, and similar narcotic symptoms, but no long-term effects
Chronic Exposure : Long-term exposure may cause effects to specific
organs, such as to the liver, kidneys, blood, nervous system, and skin.
Contains benzene, which can cause blood disease, including anemia
and leukemia.
 Handling And Storage
Handling : Keep away from fire, sparks and heated surfaces. No
smoking near areas where material is stored or handled. The product
should only be stored and handled in areas with intrinsically safe
electrical classification.

Advice on protection against fire and explosion : Hydrocarbon liquids
including this product can act as a non-conductive flammable liquid (or
static accumulators), and may form ignitable vapor-air mixtures in
storage tanks or other containers. Precautions to prevent static-
initated fire or explosion during transfer, storage or handling, include
but are not limited to these examples:
(1) Ground and bond containers during product transfers. Grounding
and bonding may not be adequate protection to prevent ignition or
explosion of hydrocarbon liquids and vapors that are static
accumulators.
(2) Special slow load procedures for "switch loading" must be followed
to avoid the static ignition hazard that can exist when higher flash
point material (such as fuel oil or diesel) is loaded into tanks previously
containing low flash point products (such gasoline or naphtha).
(3) Storage tank level floats must be effectively bonded.
For more information on precautions to prevent static-initated fire or
explosion, see NFPA 77, Recommended Practice on Static Electricity
(2007), and API Recommended Practice 2003, Protection Against
Ignitions Arising Out of Static, Lightning, and Stray Currents (2008).
Requirements for storage areas and containers : Keep away from
flame, sparks, excessive temperatures and open flame. Use approved
containers. Keep containers closed and clearly labeled. Empty or
partially full product containers or vessels may contain explosive
vapors. Do not pressurize, cut, heat, weld or expose containers to
sources of ignition. Store in a well-ventilated area. The storage area
should comply with NFPA 30 "Flammable and Combustible Liquid
Code". The cleaning of tanks previously containing this product should
follow API Recommended Practice (RP) 2013 "Cleaning Mobile Tanks
In Flammable and Combustible Liquid Service" and API RP 2015
"Cleaning Petroleum Storage Tanks".

Advice on common storage : Keep away from food, drink and animal
feed. Incompatible with oxidizing agents. Incompatible with acids.
2.5 Loading of Naphtha at Gantry
Naphtha loading procedure is given below.
1. Oil company is not involved
2. Naphtha tanker to be checked by opening of bottom valve before weighing for
ensuring presence of water/liquid inside the tanker
3. There is only liquid arm connection
4. Check operation of common lever for shutting of outlet valves of individual
chambers
5. Check for calibration/dip for each compartment
6. Check for breathers for lining up
7. Open all the chambers
8. Place liquid arm into one of the chambers from top
9. Loading is done chamber by chamber
10. Level of liquid is monitored by dip rod
11. Apply paste on dip rod to know the level
12. In case of over filling of tanker, unloading is done in an underground tank in the
gantry with the help of hose connection with tanker by gravity
13. Unloaded naphtha is transferred to naphtha storage tank intermittently by
submersible pump through naphtha supply header

Chapter –3
Calculations
 For Phase- II (TRAIN - 12)
o E-125 Condensor Heat Rejection
Given Data-
Ti=89.9 o
C = 363 K
To=35 o
C = 308 K
Volumetric flow rate = 36.3 km3/hr = 10.083 m3
/sec
m= 111.83 kmol/sec
R= 8314 J/kmol – K
For calculation of Cp constants used-
A= 1.213
B= 28.785 * 10-3
C= -8.824 * 10-6
Using-
Q = m Cp dT - (i)
Cp = A + BT + CT2
Integrating eq-(i) between limits Ti and To
Q = 504968.515 J = 144 tons
Calculations for tons of refrigeration
for Propane Refrigeration Unit (P.R.U)

o Work done by Compressor
Ist
Stage Compressor-
Given Data:
P1= 1.171 kg/cm2
=114737.805 Pa
P2= 4.3 kg/cm2
V1= 15.4 km3
/hr = 4.27 m3
/sec (at N.T.P)
= 3.086 m3
/hr (at operating conditons)
k = 1.4
Using-
Compression Ratio (Pc) = P2/P1 = 3.67
=568186.24 W = 568.15 kW
IInd
Stage Compressor-
Given Data:
P1= 4.27 kg/cm2
=418749.955 Pa
P2= 16.2 kg/cm2
V1= 36.3 km3
/hr =10.083 m3
/sec (at N.T.P)
V1= 2.39 (at operating conditions)
k=1.4
Compression Ratio (Pc) = P2/P1 = 3.794
k
k -1
P1
V1
( Pc
( k-1 / k)
- 1 )P =
1.4
1.4 - 1
11473.805* 3.086 * (3.67
(1.4-1/1.4)
- 1 )P =
1.4
1.4 -1
418749.955* 2.39* (3.794
(1.4-1/1.4)
- 1 )P =

= 1807608.54 W = 1807.60 kW
Hence, the total power consumed in a compressor-
Pt = 2.375 MW = 677 tons
o E-126 Heat Rejection
We can calculate the heat lost by estimation of the heat loss at LEF column. Since,
heat taken by the propane in E-126 is heat rejected by vapors of the LEF column.
The flow rate of the vapors has been calculated using general stoichiometry as
indicated below in the figure.
Fig 3.1 LEF Columnn
Given Data-
Ti= -18 o
C = 255 K
To= -28 o
C = 245 K
(180.3 + 74) m3
/hr
54 kg/sec
92.1 m3
/hr

m= 54 kg/sec = 2.42 kmol/sec
R= 8.314 KJ/kmol – K
Using-
Q = m Cp dT - (i)
Cp = A + BT + CT2
Integrating eq-(i) between limits Ti and To
Gases Mole
Fraction
A B * 10-3
C * 10-6
Mole
fraction x
Cp x T (in
kJ/kmol)
C1 0.65 1.702 9.081 -2.164 237.45
C2 0.25 1.131 19.225 -5.561 140.17
C3 0.02 1.213 28.785 -8.824 15.76
CO2 0.08 5.457 1.045 - 45.65
Total 1017.98
Table 3.1 – Calulation of Cp from the constants for PHASE - II
Q = 2465.06 kW = 703 tons
o V-126 flash pot Heat Rejection
Valve LIC-305 is closed. Hence, no there is no flow of propane towards V-126. So,
there is no heat rejection.
Q = 0
 For Phase- I (TRAIN - 11)
o E-125 Condensor Heat Rejection

Similar to the calculations of the Phase-II
Q = 456.37 kJ = 130 ton
o V-126 flash pot Heat Rejection
Fig 3.2 : The Basic Representation Of Chiller
The stream is used for maintaing the temperature inside the chiller stream.
So, the heat given by it equilvalent to heat taken by the chiller.
Latent heat of vaporization of propane at 298 K, L = 81.76 cal/gm
ΔHT2 = ΔHT1 (1-Tr2 ).38
(1-Tr1).38
where Tr is reduced temp.
At T =228.7 k, ΔHvap. = 105.689 cal/gm = 442.41 kJ/kg
Tin = Tout = 228.7 K

Only phase change takes place, no use of sensible heat of propane
Now, propane entering chiller = 14895.55 kg /hr = 4.14 kg/sec
L= 415.85 kJ/kg
Heat lost by the stream =m*L
Therefore,
Q = 1721.94 kW= 491 ton
o E-126 Heat Rejection
Similar to the calculations of the Phase-II
Ti= -9 o
C = 264 K
To= -35 o
C = 238 K
m= 54 kg/sec = 2.42 kmol/sec
Gases Mole
Fraction
A B * 10-3
C * 10-6
Mole
fraction x
Cp x T (in
kJ/kmol)
C1 0.65 1.702 9.081 -2.164 536.95
C2 0.25 1.131 19.225 -5.561 314.5
C3 0.02 1.213 28.785 -8.824 33.22
CO2 0.08 5.457 1.045 - 98.90
Total 983.57
Table 3.2 – Calulation of Cp from the constants for PHASE - I
Q = 2380.24 kW = 679 tons

The table shows the average losses of the naphtha during various periods of the
year.
Period w.e.f 2013-2014 Losses (in metric tons per month)
April 74
May 27
June 63
July 29
August 5
September 26
October 50
November 8
December 19
January 24
February 20
March 24
Table 3.3 – Losses in MT per month
There are many components of Naphtha as discussed earlier. So it is very complex
to analyze their respective vapor pressures and partial pressures. Hence, we have
focused on the major components and all the calculations have been performed
neglecting of the minor components.
Sr.
No.
Component Composition
in mole %
Ps at
30 o
C
(kPa)
Ps at
35 o
C
(kPa)
Ps at
40 o
C
(kPa)
Ps at
45 o
C
(kPa)
Ps at
50 o
C
(kPa)
1. Iso– pentane 15 138.29
5
163.2
7
191.6
2
223.6
0
259.5
3
2 Pentane 25 81.63 97.26 115.1
5
135.5
0
158.3
3
Estimation of Losses of Naphtha at
Loading Gantry

3. 2,3-
dimethylbutan
e
2 37.93 45.98 55.12 65.76 77.96
4. 2-
dimethylpenta
ne
9 30.8 41.06 51.33 61.61 77.01
5. 3-
methylpentane
4 30.8 41.06 51.33 61.61 77.01
6. Hexane 10 24.75 30.35 36.94 44.62 53.51
7. 2,2-
dimethylpenta
ne
5 34.35 41.77 50.4 60.4 71.9
8. Benzene 5 15.4 16.7 24.3 29.74 36.33
9. Cyclohexane 7 16.33 20.16 24.72 30.07 36.33
10. 2-
methylhexane
2 12.55 15.4 18.48 22.49 28.75
11. Heptane 3 7.69 9.74 12.22 15.12 18.72
12. Methyl
cyclohexane
5 7.73 9.72 12.11 14.97 18.34
13. Toluene 3 4.86 6.2 7.85 9.84 12.24
Table 3.4 – Calculation of Naphtha’s Vapor Pressure at different
temperature(this is further used for calculation partial pressures)
Sample Calculations at T = 30 o
C.
Ptotal = 53.03395 kPa = 0.54078 kg/cm2
Density = 0.69 gm/cm3
Diameter = 2 in = 0.0508 m
Length = 10 cm
Using Darcy–Weisbach equation,
Where the pressure loss due to friction Δp (Pa) is a function of:

 the ratio of the length to diameter of the pipe, L/D;
 the density of the fluid, ρ (kg/m3
);
 the mean velocity of the flow, V (m/s), as defined above;
 Darcy Friction Factor; a (dimensionless) coefficient of laminar, or turbulent
flow, fD.
fD = 0.026 (calculated from Moody Diagram, taking € = 0.15 mm )
From, above equation the velocity is found out to be,
V = 0.0421687 m/s
Area of the outlet = 0.00203 m2
Therefore, Volumetric flow rate = 0.085 * 10-3
m3
/sec
On an average 6 trucks are loaded per day and each loading takes 45 minutes
approximately.
Loss of Naphtha is 0.9639 MT.
Fig 3.3 The Temperature v/s Losses Curve
0.9639
1.5982
1.7462
1.8971
2.05982
y = -0.02x4 + 0.2817x3 - 1.4328x2 + 3.2612x - 1.1262
R² = 1
0
0.5
1
1.5
2
2.5
30 35 40 45 50
losess

Chapter - 4
Results and Discussions
Phase – I
Given Data
Heat
Rejected/
Absorbed or
Power
Produced
Evaporator E-126
Ti= -9 o
C = 264 K
To= -35 o
C = 238 K
Volumetric flow rate = 162.2 m3
/hr
m= 54 kg/sec
2380.24 kW
= 679 tons
Flash Pot V-126
Temperature is constant at -44.3 o
C
Phase change takes place
λ = 415.85 kJ/kg
m = 4.14 kg/sec
1721.94
kW= 491
tons
Table 4.1 –Results of calculations for Phase – I
Hence, total ton of refrigeration is equivalent to (679 + 491) tons.
QL = 1170 tons
The calculation of tons of refrigeration of the Phase- I is being carried by the
summation of the Heat lost/gained by the vessels E-126 and V-126. This done by
the basic analysis of the refrigeration cycle. The calculations are aptly described in
the Chapter - 3.
From the calculations it is evident that the tons of refrigeration is more in the Phase
– I than in the Phase – II. The reason to this that the flash pot is not in function in
Phase – II as the Chiller is just been replaced and it is being operated at a high

efficiency rendering V-126 useless as the heat requirements are met without it.
Phase – II
Given Data
Heat
Rejected/
Absorbed or
Power
Produced
Compressor 1st
Stage
P1= 1.171 kg/cm2
=114737.805 Pa
P2= 4.3 kg/cm2
V1= 15.4 km3
/hr = 4.27 m3
/sec (at N.T.P)
V1= 3.086 m3
/sec (at operating conditons)
568.15 kW =
162 tons
Compressor 2nd
Stage
P1= 4.27 kg/cm2
=418749.955 Pa
P2= 16.2 kg/cm2
V1= 36.3 km3
/hr =10.083 m3
/sec (at N.T.P)
V1= 2.39 m3
/sec (at operating conditions)
1807.60 kW
= 515 tons
Condenser E-125
Ti=89.9 o
C = 363 K
To=35 o
C = 308 K
Volumetric flow rate = 36.3 km3/hr = 10.083
m3
/sec
m= 111.83 kmol/sec
504.97 kW =
144 tons
Evaporator E-126
Ti= -18 o
C = 255 K
To= -28 o
C = 245 K
Volumetric flow rate = 162.2 m3
/hr
m= 54 kg/sec
2465.06 kW
= 703 tons
Flash Pot V-126
Valve LIC-305 is closed
Hence, no there is no flow.
-
Table 4.2 –Results of calculations for Phase – II
Hence, total tons of refrigeration is equivalent
QL = 703 tons

W = 677 tons
QH= 144 tons
Losses of Naphtha per day at different temperatures are,
Temperature Losses in MT
30 o
C 0.9639
35 o
C 1.5982
40 o
C 1.7462
45 o
C 1.8971
50 o
C 2.05982
Table 4.3 –Net Losses of Naphtha in MT at different temperatures
Initial boiling point of the naphtha is 35o
C. At the loading gantry some losses arise
as the vapor pressure of components of naphtha is equivalent to their partial
pressure. This kind of vapor losses is uniquely associated with only Naphtha Loading
Gantry, as it is done open to atmosphere and there is absence of any vapor
balancing line to counter the vapor formation and recirculate them. The main
components lost are the low molecular weight hydrocarbons in the Naphtha.
The mole % of pentane and iso-pentane is about 40%, there are some traces of
even some isomers of butane. These hydrocarbons are generally lost in from of
Vapors.
Loading Losses of Naphtha are not continuous in nature and vary widely with
atmospheric conditions. As evident in Table 3.3 the losses are huge in extreme
summers as the atmospheric temperature is as high as 50 o
C and minimal in
extreme winters at a temperature of 20 o
C. This variation is due to the fact that at
lower temperature less % components of Naphtha reach to the juncture of vapor
formation then compared to higher ones. Thus, influencing the losses.
Loss of Naphtha are severe from Health and Safety issues as the chemical is highly
hazardous and care must be taken to minimize them.

Chapter - 5
Conclusion
The importance of this project lies in gaining the engineering experience and
knowledge which is required in industries and is not taught in class room. Also its
significance lies in the exposure of the engineering responsibilities and ethics.
The calculation of tonnage is provided to E-126 condenser and E-101 chiller by PRU
gives the idea of the working of the any refrigeration system. We found from the
calculation that heat absorbed by propane refrigerant from E-126 is more than that
of absorbed by it from E-101 for phase-I and in phase-II only heat absorbed by E-
126.
Recovery of Naphtha can be done by:
1. We can reduce the vapor loses by reducing the temperature of naphtha
before the loading by the heat exchanger.
2. The time management is another option for the reducing the losses. The
problem is the high temperature in summer but in winter and rain its
favorable. Hence, we pursue loading at the phases when temperature is
low viz. morning and evening.
Though, the methods have their limitations and the question always will be what
is more viable and feasible?

References
1. Perry’s Chemical Engineering Handbook, Seventh Edition.
2. Introduction to Chemical Engineering Thermodynamics, J. M .Smith, H.C.
Ness, M.M. Abbott, Mc Graw Hill Publications.
3. Thermodynamics: A Engineering Approach, Thomas A. Cengel, Micheal A.
Boles, Mc Graw Hill Publications.
4. Unit Operations Of Chemical Engineering , 5th
Ed, McCabe and Smith, Mc
Graw Hill Publications.

List of Tables
 Table 2.1 General Summary of Product Types and Distillation Range
 Table 3.1 – Calulation of Cp from the constants for PHASE - II
 Table 3.2 – Calulation of Cp from the constants for PHASE - I
 Table 3.3 – Losses in MT per month
 Table 3.4 – Calculation of Naphtha’s Vapor Pressure at different
temperature
 Table 4.1 –Results of calculations for Phase – I
 Table 4.2 –Results of calculations for Phase – II
 Table 4.3 –Net Losses of Naphtha in MT at different temperatures

List of Figures
 Fig 1.1 Layout of Gas Processing Unit (GPU)
 Fig 1.2 Process Flow Diagram TR-12
 Fig 2.1 A schematic refrigerator
 Fig 2.2 Schematic of Propane Refrigeration Unit
 Fig 3.1 LEF Columnn
 Fig 3.2 : The Basic Representation Of Chiller
 Fig 3.3 The Temperature v/s Losses Curve

List of Photographs
 Schematic Of HVJ/GREP/DV Pipeline
 Gas Compressor Station
 Centralized Pipeline Maint. Base
 LPG Phase 1(Train 11)
 LPG Phase 2 (Train 12)

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