1. 1
Vocational Training Report
Indian Farmers Fertiliser Cooperative
Kalol Unit

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Vocational Training Report
PANDIT DEENDAYAL PETROLEUM UNIVERSITY,
School Of Petroleum Technology,
Raisan, Gandhinagar-382007.
Submitted by,
Daxit Akbari-14BPE004
BACHELOR OF TECHNOLOGY
IN
[PETROLEUM ENGINEERING]
Training Period :-26th December 2016 to 10th January 2017

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ACKNOWLEDGEMENT
It’s really a matter of pleasure for me to submit this vocational
training report at the end of training period from 26.12.2016 to
10.01.2017 at IFFCO-Kalol Unit.
At this moment, I am very thankful to INDIAN FARMERS
FERTILISER COOPERATIVE LTD. (IFFCO)-KALOL UNIT
for providing me a wonderful chance of working in company. I would
like to show my deep gratitude towards the people who made it
possible for me to have this training. I would like to present my
heartiest thanks to JGM(Technical) O P Dayama sir and Senior
Manager-Training, for accommodating in the plant and helping me
through the planning of my internship. I would like to express my
sincere gratitude to Mr. Vitthalbhai Radadiya – Director IFFCO,
without whose support, I would never have got the internship in first
place. I would also like to thank all the Engineers and Technicians of
IFFCO-Kalol, without their boundless cooperation and help I would
have not been able to obtain such vast knowledge and information and
to complete this report. I express gratefulness to all for their
cooperation and support.
Lastly, I thank all others, especially my co-trainees and my
family members who in one way or the other helped me in successful
completion of my work.
Thank you.
Daxit Akbari

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ABSTRACT
Indian Farmers Fertiliser Cooperative Limited (IFFCO) was established
on 3rd November, 1967 as a multiunit cooperative organization of board
objectives of augmenting fertilizer production, ensuring fertilizer
availability at farmers door step, strengthening cooperative fertilizer
distribution system and educating training and guiding the farmers for
improving agriculture productivity. IFFCO the world’s largest cooperative
company maintained its place in the first 100 by securing 53rd rank among
Fortune’s 500 companies in India in 2015.
Commissioned on Nov.05, 1974 Kalol was IFFCO’s second bigproduction
facility and the most efficient. It is also the mother unit of IFFCO. IFFCO-
Kalol fertilizer unit is based on the natural gas supply from Reliance
Industries, located at about 18kms away from the capital of Gujarat,
Gandhinagar.
The report mainly consist of various plants Ammonia plant, Urea plant,
Utilities consisting of Cooling Tower, Demineralization (DM) plant, Inert
gas-plant air and instrument air production unit, Steam generation plant
(BHEL-Boiler), Offsite include Narmada Water Treatment plant, Effluent
Treatment plant(ETP), Ammonia Storage, Bagging and Material Handling
unit. The plant works on maximum recovery basis and has minimum
effluent discharge as used in horticulture site.
IFFCO-Kalol has three ammonia storage tanks which is used as a backup
for urea generation and also supplies the liquid ammonia at Kandla unit of
IFFCO. The IFFCO- Kalol urea and ammonia plant is based on technology
of M/S Stamicarbon, M/S Haldor Topse, M/S Snamprogetti, M/S Kwellog.

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Thus IFFCO-Kalol is one of the finest and the most efficient plant
producing urea fertilizer in India.
Table of content
No. Subject Page
No.
1 Introduction 6
2 Fire and safety 8
3 Ammonia Plant 9
4 Urea Plant 17
5 Utility 27
6 Offsites 35
7 Conclusion 39

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INTRODUCTION
Indian Farmers Fertilizer Limited also known as IFFCO is the world’s
largest Fertilizer Cooperative Federation based in India. The Indian
Farmers Fertiliser Cooperative Limited (IFFCO) was registered as a
multiunit co-operative society, under the co-operative society’s action
November 3, 1967. IFFCO, a pioneer in the cooperative sector, has been
making a steady progress in the realms of fertilizer production, capacity
utilization and rendering services to the farming community.
The number of co-operative societies associated with IFFCO has risen
from 57 in 1967 to 40,000 at present. On the enactment of the multistate
cooperative societies act 1984 & 2002, the society The is deemed to be
registered as Multistate Cooperative Society.
IFFCO’S five modern fertilizer plants at Kalol and Kandla in Gujarat and
Phulpur and Aonla in Uttar Pradesh and Paradeep in Orissa have a total
annual production capacity of 56.63 lakh tones of fertilizer. The annual
production capacity of five plants is given below. IFFCO has retained 7th
Rank in the Business Standard ranking in 2016 out of 200 listed
companies. Iffco has been ranked 53rd in fortune 500 list in 2015.

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IFFCO KALOL UNIT
The IFFCO Kalol Unit, spread over on 96 hectares of land, is located 26 kms
away from Ahmedabad on the Ahmedabad Mehsana state highway and is 18
kms away from the capital of Gujarat- Gandhinagar. The unit started commercial
productionin April’1975. The unit consists ofplants to produce ammonia, urea,
liquid Ammonia stored at -33 C along with offsite facilities. Originally the 910
tpd ammonia plant was based on natural gas steam reforming process of M/s.
M.W. Kellogg, USA and 1200 tpd urea plant was based onCO2 stripping process
of M/s. Stamicarbon, The Netherlands. Both the plants have been revamped in
1997 to enhance capacities to 1100 tpd ammonia and 1650 tpd urea. The
Natural gas (NG) available in the vicinity of the unit is supplied by Reliance
Industries, GSPL, RGPTIL, and KG D6 Basin. Associated gas and LSHS are
used as fuels. Water is supplied by Narmada Reservoir at Jaspur which is treated
at Narmada Water Treatment Plant and is used in various plants at IFFCO-Kalol,
the bore wells are currently not operated which were used earlier installed
around the unit. Power is supplied by Gujarat Electricity Board (GEB) and
UGCVL.
Consumption of inputs for the production of 1100 tonnes of ammonia 1650
tonnes of urea every day are given below.
Natural gas : 450,000 Sm3/day
Associated gas : 200,000 Sm3/day
Water : 18,000 m3/day
LSHS : 140 tonnes/day
Power : 8,500 KVA
Chemicals : 60 tonnes/day

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PRODUCTION PERFORMANCE
The productionrecords for all four units are excellent. Since inception, the
capacity utilization achieved is always higher than the national average
IFFCO has won several awards for the Fertilizer Association of India (FAI),
National productivity Council and national and international safety councils
for outstanding production performance and in safety measures.
Introduction to IFFCO, kalolunit :
The IFFCO Kalol Unit , spread over on 96 hectors of land is located 26 kms.
away from Ahmedabad on the Ahmedabad Mehsana state highway. The unit
started commercial production in April 1975. The unit consists of plant to
produce ammonia, urea, liquid carbon dioxide and dry ice along with offsite.
Originally the 910 tpd ammonia plant was based onnatural gas steam reforming
process ofM/s. M.W. Kellong, USA and 1200 tpd urea plant was based on co2
stripping process of M/S Stamicarbon, The Netherlands. Both the plant have
revamped in 1997 to enhance capacity to 1100 tpd ammonia and 1650 tpd urea.
RLNG is used as feed stock for ammonia and associated gas as fuel. Water is
supplied from Narmada Canal from Jaspur. Power is supplied by GEB.
Various Plants:
Ammonia Plant :
The plant is being designated to produce1150 metric-tonnes of ammonia per
day based on M.W. Kellogg Steam Reforming Process ofUSA. RLNG is used
for ammonia productionis supplied by Reliance Petrochemicals. From total
production, about 950 metric-tonnes ammonia per day is used in the urea plant
and remaining is stored in atmospheric storage tank.
Urea plant :
The 1650 metric-tonnes per day plant is based on Stamicarbon CO2 Stripping
processsengineered by Humphreys and Glasgow, U.K. The main raw material
ammonia and carbondioxide are from ammonia plant.

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Utility plant :
(I) Water Treatment Plant
(II) Cooling Towers
(III) Air Compressorand Inert Gas Generation
(IV) Steam Generation
Offsite plant :
(I) Storage Tanks
(II) Narmada Water Treatment Plant
(III) Effluent Treatment Plant
Organizationalstructure :
Head office of IFFCO is located at New Delhi. It houses corporate staff
function as:
(I) Engineering Service Division
(II) Management Service Division
(III) Finance and Accounts
(IV) Personnel and Administration
(V) Marketing
List of plant and capacity:
ProcessUnits :
Ammonia : 1160 Tons / Day
Urea : 1650 Tons / Day
Offsite & Utilities :
Water Treatment plant : 2570 Tons / Day
Steam Generation Plant : 1920 Tons / Day
Instrument and Plant Air : 1800 Nm3 / hr
Cooling Tower : 22900 Tons / Day
Raw Water Storage : 2600 m3

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Ammonia Storage: 15000 Tons
FIRE AND SAFETY UNIT
Safetyoverview:-
The Significance of Safety & Health in chemical industries has been a vital
issue inachieving productivity and edge in the competitive world.IFFCO’s
continuous effort to implement safety, health and environment systems in
the organization have been appreciated and recognized by several
government and safety regulating bodies. Material Data Sheet (MSDS)
gives the detailed information regarding the potential hazards and safety
measures in every Industries. As per the Government norms IFFCO-Kalol
follows each and everyguidelines mention by the Government of India and
Gujarat.
Possible threats :-
 Dangerous Materials.
 Hazards of Pressure Vessels.
 Hazardous chemical reactions.
 Hazards of unit operations.
 Flammable gases, vapors and dust hazards.
 Hazards due to instrument failure.
 Hazards due to corrosion.
Fire and SafetyEquipments
Types of safety equipments are at IFFCO-Kalol:-
 Hard Hat (Safety Helmet)
 Safety Shoes & Goggles
 Gas Detectors

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 Eyewash/Ammonia wash station
 Ear Protection
 Dust Masks & Respirators
 Safety Signs
 Flashlights
 Lightning Arrestors
 First Aid Kits
 Welding Equipment
 Wind direction indicators
Ammonia Manufacturing Plant
Ammonia plant of IFFCO-Kalol was commissioned in 1974 based on natural
gas steam reforming process which follows following stages one by one.
 Natural gas desulfurization
 Catalytic Steam Reforming
o Primary steam reforming
o Secondarysteam reforming
 Carbon monoxide shift (HT & LT)
 Carbon dioxide removal
 Methanation
 Ammonia synthesis
Flow diagram of ammonia synthesis by air reforming process:-

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NATURAL GAS SUPPLY AND DESULPHURIZATION:-
The natural gas, which is used as feedstockfor ammonia plant is supplied at the
battery limits by Reliance/GSPC/K6 Godavari Basin from their gas fields. Two
turbine driven centrifugal compressors of adequate capacity in series are
installed to boost up the pressure of natural gas upto 39 kg/cm2g.Control valve
and relief valve are given in series if there is any kind of abnormality in pressure
rise for safety and pressureregulation. Natural gas is then split into two streams
as Feed Stock and Fuel Stock. Natural gas is then sent to Desulphurizer. Natural
gas contains sulphur compounds in the form of sulphides, disulphides,
mercaptan sulphur and thiophenes etc. which are poisonous to the catalysts used
in ammonia plant. The process of removing these sulphur compounds is called
desulphurisation. The process employed is adsorption and adsorbent used is
activated carbon catalyst. The naphtha performer is in decommissioning stage
as the plant now operates at 100% Natural gas feed supply.

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REFORMING (PRIMARY, SECONDARY REFORMING &
WASTE HEAT BOILERS):-
Reformer consists of three parts as follows:-
1. Primary Reformer
2. SecondaryReformer
3. Waste heat Boiler
PRIMARY REFORMING:-
The natural gas after removal of sulphur compounds in Desulphurizer enters
feed preheat coil in the convection section of primary reformer furnace. The
natural gas temperature is raised by the flue gas coming out of the convection
zone of the furnace. Then natural gas is mixed with superheated steam. The
mixture of natural gas and steam mixed feed preheat coil in the convection zone.
From outlet of mixed feed pre heat coil, reformer feed goes to primary reformer.
The reformer feed then passes throughthe catalyst packed reformer tubes. There
are 336 tubes arranged in eight rows of 42 tubes each
As the reaction is endothermic i.e. it absorbs heat, the heat is supplied byburning
mixed fuel gas as fuel in top fired 126 top fixed arch burners. The catalyst used
in the primary reformer is nickel based. Top portion of the tubes is filled with
potashbased nickel catalyst. Primary reformer exit stream is taken to secondary
reformer.
The reactions taking place can be written as follows:-
CnH2n+2 + nH2O n CO + (2n+ 1) H2, H > 0
CH4 + H2O CO + 3H2 H = 49.28 kcal/kgmole
CH4 + 2 H2O CO2 + 4H2 H = 39.44 kcal/kgmole
CO + H2O CO2 + H2 H = - 9.82 kcal/kgmole
SECONDARYREFORMER:-
The partially reformed gas from primary reformer enters the secondaryreformer
Process air supplied by process air compressor is preheated in steam air preheat
coil.

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The temperature of gas inlet to secondary reformer is around 7860 C .The parts
of H2 and other combustible gases in the process gas burn with oxygen, leaving
the nitrogen required to make ammonia. The amount of air is fixed by the
nitrogen requirement for the ammonia synthesis.. The reaction with air in
secondaryreformer (combustion zone) is as follows:-
2H2 + O2 + 3.715 N2 2H2O + 3.715 N2 + Heat
2CH4 + 3.5 O2 + 13.003 N2 CO2 + CO + 4 H2O + 13.003 N2 + Heat
The reaction is exothermic; temperature is around 12350 C. Catalysts used are
high temperature resistant chromia and high activity nickel at the top and bottom
respectively. The methane steam reforming reaction in secondary reformer is
same as that given for primary reformer.
WASTE HEAT BOILERS:-
Reformed gas with process steam at 9350 C from the bottom of secondary
reformer passes through the shell side oftwo parallel flow refractory lined water
jacketed primary waste heat boiler. Then the gas passes through the tube side of
secondarywaste heat boilers in which it is cooled to the desired high temperature
shift converter inlet temperature. These waste heat boiler generate the major
portion of the steam required to operate the unit. The temperature of the gases
reduced to 366o C. 105 ata steam is generated by secondary reformer heat in
waste heat boiler.
WATER GAS SHIFT REACTION:-
(a) High temperature shift conversion:-
The reformed gas enters the high temperature section of shift converter and
flows through the catalyst bed. The catalyst used in high temperature shift
converter is copperpromoted iron oxide catalyst in reduced state. The following
reaction takes place in shift converter:-
CO + H2O CO2 + H2 H = - 9.82 kcal/kgmole

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As indicated by this equation, most of the carbon monoxide is converted to
carbon dioxide gaining an additional mole of hydrogen per mole of carbon
monoxide.
(b) Low temperature shift conversion
The gas coming out of high temperature shift converter still contains about
3.36 % carbonmonoxide, which should be reduced to within tolerable limit
before sending the gas for CO2 removal and Methantion.This is accomplished
in low temperature shift converter. The gases leaving from HTS goes to Low
temperature Guard Shift Convertor. Low temperature shift converter contains
high coppercatalyst. The shift reaction is same as in high temperature shift
converter. LTS inlet gas temperature must have 200 C superheat to avoid any
chances of condensation. Condensation of LTS inlet gas damages the catalyst
physically, reduces the strength and activity of the catalyst. LTS catalyst is
fixed and costlier in nature which cannot be removed during regular plant
operation so direct use of gas from HTS to LTS can damaged the catalyst
present in LTS. The LTS-Guard also contains coppercatalyst but can be
changed during regular plant operation.
CO2 ABSORPTION AND STRIPPING:-
In this sectionthe bulk ofCO2 in the raw synthesis gas is removed by absorption,
using 40% aqueous activated methyl diethanol amine (a-MDEA) solution {CH3-
N(CH2-CH2-OH)2}, at relatively high pressure and low temperature. The
absorptionofCO2 involves the reaction ofdissolved CO2 in water with a-MDEA
to form a loose chemical compound which can be easily dissociated at higher
temperature and lower pressure. Following reaction takes place:-
CO2 + H2O H2CO3
The raw synthesis gas at a pressure of 27.3 kg/cm2g and temperature of 630 C
containing about 18 % dry volume of CO2 is introduced at the bottomof CO2
absorber. Absorberis a cylindrical tower fitted with twenty perforated sieve
trays one above the other spaced at equal distance. Lean a-MDEA solution
from CO2 stripper bottom is cooled in a-MDEA solution exchanger and then in

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a-MDEA solution cooler by rich a-MDEA and cooling water respectively. a-
MDEA circulation pumps introduces the lean a-MDEA solution over the top
tray of the tower. Solution flows downwards, counter current to the gas flow.
Almost all the CO2 is absorbed by the solution, leaving only small traces of CO2
in absorber outlet gas. The gas before leaving the tower passes through a
demister pad to remove the entrained solution, if any.
Rich a-MDEA solution from the bottom of absorberis sent to CO2 strippers for
regeneration. Strippers operate at a pressureof 0.74 kg/cm2g and temperature of
1180 C at the bottom. Rich a-MDEA solution is heated by heat exchange with
the lean solution coming from the bottom of strippers, in a-MDEA solution
exchangers and then splits into equal stream as feed to CO2 strippers through
control valves.
CO2 stripper towers are fitted with seventeen perforated sieve trays each spaced
equally one below the other. The solution enters above the top tray. The function
of CO2 strippers is regeneration of rich a-MDEA solution by liberating CO2
absorbed in it, so that the solution can be reused in absorber. The solution in the
stripper bottomis heated in reboilers.
The solution from strippers while passingthrough the tube sideof these reboilers
is heated to 1180 C and by thermosyphoning the vapor solution mixture returns
to strippers from the top of reboilers. As the vapors rise through the trays, the
rich a-MDEA solution together with the reflux pumped from CO2 stripperreflux
drum comes in contact with it and condenses the vapors. The CO2 thus stripped
off in strippers along with water vapor and a-MDEA vapor leave strippers.
These are cooled by cooling water in CO2 stripper condensers.
The CO2 (by productof ammonia plant) is sent to urea plant and balance if any,
is vented by to atmosphere. The lean a-MDEA solution form the bottom of
strippers is reused after cooling, for absorption of CO2 in absorber.
METHANATION:-
For ammonia synthesis a very pure gas mixture of H2 and N2 in the ratio of 3:1
(by volume) is required and the small amounts of CO2 and CO are poisonous to
the ammonia synthesis catalyst. These oxides are removed by converting them
into methane in Methanator by a highly active nickel based catalyst in presence

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of H2. This step is known as Methantion. Methane has no action on the ammonia
synthesis catalyst, but it accumulates in the synthesis loop as inert. Methantion
reactions are given below:-
CO + 3H2 CH4 + H2O H = - 49.28 kcal/kgmole
CO2 + 4H2 CH4 + 2H2O H = - 39.44 kcal/kgmole
Both these reactions are highly exothermic, and hence extreme care is to be
observed while operating Methanator. The unit is properly protected with high
temperature alarms and shut off systems. Methanator vessel is filled with nickel
catalyst.
The hot Methanator outlet gas, which is called as synthesis gas is cooled by
exchanging heat with boiler feed water, Methanator effluent cooler and finally
in suction chiller to 80 C where ammonia from second stage refrigerant drum is
used as cooling media. The gas then flows to synthesis gas compressorsuction.
AMMONIA SYNTHESIS:-
The pure synthesis gas mixes with the recovered hydrogen from the purge gas
recovery plant. The mixture is then compressed in a turbine driven two case
centrifugal compressors. Recyclegas mixture consisting of ammonia (14.75 %
by volume) and unreacted reactants from synthesis converter is admitted in the
last wheel of the second case and mixes with synthesis gas mixture (make up
gas as it is called) and undergoes final stages of compression to approximately
137 kg/cm2g and temperature of 65.30 C. The compressor discharge gases are
then cooled. Dry basis (vol. %) are, H2: 60.48, N2: 20.17, NH3: 11.68, CH4:
5.00 Ar: 67
The ammonia synthesis reaction taking place at elevated temperature and
pressure in presence of a promoted iron catalyst is as under:-
N2 + 3H2 2NH3 H700 K = - 12.55 kcal/kgmole

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As the reaction is exothermic, a rise in temperature lowers the equilibrium
conversion of ammonia and at the same time accelerates the reaction rate. If
reaction is near equilibrium, rise in temperature will lead to decrease in
conversion and vice versa.
Since synthesis of ammonia involves a decrease in volume, rise in pressure will
favor reaction equilibrium. At the same time reaction rate is also accelerated by
increase in pressure. Hence higher pressure favors conversion.
Other factors which influence operation of the converter include circulation rate,
ratio of H2: N2 in the feed gas, inert content in the loop, percentage of ammonia
into converter feed and poisoning and ageing of catalyst. All these factors are
inter-dependent and a change in one will have effect on others. Only experience
will dictate what steps should be taken to compensate the change so that the
system remains in good control.
REFRIGERATION:-
The primary purpose of the refrigeration system is to make available liquid
refrigerant ammonia at different temperature which is required to circulate
through chillers for condensing product ammonia from converter feed. Further
it is also required:-
 To coolmakeup gas for separation of water at the suction and interstage
of compressor.
 To condense and recover liquid ammonia from purge and flash gases.
 To coolthe product run down to -
 To provide refrigeration duty in refrigerant cooler of PGR plant.
 To degas the inert from productammonia.
AMMONIA:
Physicaland Chemicalproperties:
 At Atmospheric temperature & PressureAmmonia is a sharp colorless
gas.
 Formula : NH3
 Specific Gravity : 0.682

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 M.W. : 17.03 gm/mole
 Critical temperature : 132.14 °C
 Auto ignition temperature : 651 °C
 Boiling Point : -33.3 °C
 Freezing point : -77.7 °C
 Nature : Alkaline
 Odor: Colorless
 NH3 is very soluble in cold water and NH4OH.
 NH3 is readily released from liquid Ammonia with increase in
temperature.
Hazardous Properties :
 When Ammonia stored in closed container NH3 exert to vapor which
increase rapidly with rising temperature.
 NH3 will explosive mixture with air and Oxygen.
 Moist NH3 will react rapidly with Cu & Zn.
 The use of the Hg in contactwith NH3 should be avoided since under
certain condition explosive chemical compounds resulting.
 NH3 is an irritating gas & will affect muscles, membrane & eye.
Hazardous identification :
 Color : colorless
 Physical form : gas, liquid
 Odor: pungent odor
 Physical hazards : Containers may rupture or explode if exposed to heat
First aid measures :
Inhalation :
If adverse effects occur, remove to uncontaminated area. Give artificial
respiration if not breathing. If breathing is difficult, qualified personnel should
administer oxygen. Get immediate medical attention.
Skin contact :

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Wash skin with soap and water for at least 15 minutes while removing
contaminates unclothing and shoes. Get immediate medical attention.
Thoroughly clean and dry contaminated clothing and shoes before reuse.
Destroy contaminated shoes.
Eye contact :
Immediately flush eyes with plenty of water for at least 15 minutes. Then get
immediate medical attention.
Ingestion :
Do not induce vomiting. Never make an unconscious personvomit or drink
fluids.
Give large amounts of water or milk. When vomiting occurs, keep head lower
than hips to help prevent aspiration. If person is unconscious, turn head to side.
Get medical attention immediately.

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UREA MANUFACTURING PLANT
Urea plant at IFFCO-Kalol was commissioned in 1974 based on CO2 Stripping
process.
The Urea process consistsofthe following steps.
1. CO2 supply and compression
2. NH3 supply and pumping
3. Reaction/High pressuresynthesis
4. Low pressure/Recirculation system
5. Evaporation and Prilling System
6. Urea hydrolyser and Desorber
7. Steam and condensation
CO2 supply and compression :-
The CO2 gas is available from ammonia plant at normal pressureof 0.14 to 0.22
kg/cm2g and at a temperature of50° C to 60° C. This gas is cooled and saturated
in CO2 spray cooler with spray water. CO2 and water flows counter currently
through packed bed of polypropylene pall rings for cooling. A demister pad
above the distribution tray is provided to prevent the water carryover along with
exit CO2 from spray cooler.
Water from the bottom of the spray cooler is sent to the cooling tower by CO2
spray cooler sump pump. The exit saturated CO2 with water vapour enters the
CO2 knock out drum where the moisture is knocked out and drained.
Anticorrosion air is injected into the cooled CO2 stream with the help of
anticorrosion air blowers. The air is required to maintain the oxygen level of
0.60 % in the CO2 stream for HP equipments passivation to prevent corrosion.
The CO2 leaving knock out drum is compressed inHitachi make CO2 centrifugal
compressor.
NH3 supply and pumping :-
Liquid ammonia directly from ammonia plant enters the urea plant battery limit
at 20 kg/cm2a and 40° C. The alternate source for ammonia supply is from the

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atmospheric ammonia storage tank. The cold liquid ammonia is preheated to
40° C in the ammonia pre heater.
Liquid ammonia from filter outlet enters the ammonia suction vessel which
serves the purposes of providing a suction volume for HP ammonia pumps and
acting as a pulsation dampener. The liquid ammonia from the ammonia suction
vessel is pumped at reaction pressure of 153 kg/cm2a. Out of total ammonia
discharged by pumps, 90-95 % ammonia goes to HP Carbamate condenserand
5-10% goes to autoclave.
Reaction/High pressure synthesis (HP system):-
a) HP stripper
CO2 gas with 0.60 % oxygen and inert discharged from CO2 compressorat157
kg/cm2a and 115 to 120° C enters the stripper. Autoclave overflow line leads
to HP stripper at the top channel. The liquid dividers are fitted over each tube
having ferrule. Each ferrule in the liquid divider has three holes each of 2.6 mm
diameter through which the liquid flows into the tubes. This exchanger acts like
a falling film counter-current heat exchanger. The efficiency of the exchanger
depends on the formation of liquid film. Liquid distribution in the tube is very
important. Liquid starvation in tube may happen when there is loss of liquid
level in autoclave or blockage of ferrules holes. Stripper tubes under this
condition will beover heated resulting in heavy corrosion and tube failures. CO2
while rising through the tubes picks up heat from falling solution and strips off
NH3 and CO2 from the Carbamate. From HP stripper top channel CO2 along
with liberated NH3 is taken toHP Carbamate condenser. Saturated steam at 21.8
kg/cm2g and 216° C is introduced at the shell side of the HP stripper to provide
the heat required for stripping.
Urea Carbamate solution is collected at the bottom channel of the HP stripper.
This solution is let down from 153 kg/cm2g to 2.3 kg/cm2g across the level
control valve. It is imperative that to maintain the stripper working efficiency,
both gas and liquid flow through each tube must be continuous and even.

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b) HP condenser
The vapour (NH3 & CO2) liberated from the HP stripper flows upwards to the
top channel of HP Carbamate condenser below the packed bed. Liquid
ammonia from HP ammonia pump at apressureof153 kg/cm2a and 45° C enters
the top channel. HP stripper exit gas is rich in CO2 and the NH3/CO2 mole ratio
is around 1.7. The presence of 2.5 % water and slightly higher system pressure
makes the optimum mole ratio to around 3.0.
Dilute Carbamate solution generated in LP system is pumped with HP
carbamate pumps to HP condenserand HP scrubber. Dilute carbamate line joins
the inlet liquid ammonia line to HP condenser. About 65 % of the carbamate
solution is fed to HP condenser. Theremaining carbamate is fed to HP scrubber.
Carbamate solution joins the liquid ammonia stream and then enters HP
condenser. The mixed stream flows through the packed bed, located above the
liquid distribution tray. Some of the vapours (NH3 and CO2) enter the packing
and a part of it is condensed within the packing. Uncondensed vapours flow
through the tubes and are condensed to carbamate.
Boiler feed water/ condensate enters the shell side from 4 ata steam drum
through the four down comers and generated steam rises up through the steam
risers and enters the steam drum. Liquid carbamate solution and uncondensed
gases leaves HP condenser from separate nozzles at the bottom and enters the
bottom channel of autoclave.
At the operating condition prevailing in the HP condenser, the rate of carbamate
formation is proportional to the rate of removal of heat of exothermic reaction.
The pressureprevailing in the steam drum should not be brought down below a
certain value otherwise the crystallisation temperature of carbamate (153° C)
would be reached. 90 % (v/v) of the vapours condense in high-pressure
condenser and the remaining 10 % are condensed in autoclave thereby
supplying necessary heat for urea formation from carbamate

24. 24
C) Autoclave (Reactor)
The carbamate solution and uncondensed NH3 and CO2 from the HP carbamate
condenser are introduced at the bottom of the autoclave. A part of liquid
ammonia from HP ammonia pump is also introduced at the bottom of the
autoclave. Quantity of ammonia required to be introduced into the autoclave is
determined from the process conditionand plant load. Autoclave receives liquid
ammonia, carbamate solution and uncondensed NH3, CO2, O2 and inert from
HP condenser and carbamate solution from HP scrubber. All the four streams
join at four different nozzles at the bottom of the autoclave and rises to the top
through eleven sieve
trays. Liquid mixture ofurea, carbamate and water overflows to the downcomer
to the HP stripper.
A radioactive source (Cobalt -60) is provided for level measurement of
autoclave. Loss of liquid level in autoclave will evidently create a number of
problems in the system. Due to loss of liquid level, CO2 will flow in reverse
direction to autoclave via down comer and pressure rise will be very quick and
HP condensertemperature will fall sharply.
The inert and unconverted NH3 and CO2 exit the autoclave through an overhead
line to HP scrubber. HICV, located on the autoclave gas exit line, controls the
autoclave pressure and consequently high-pressure system in emergency. To
protect high-pressure system from over pressurisation, relief valves set at 161
ata are installed on autoclave top exit gas line.
d) HP scrubber
Uncondensed NH3 and CO2 and non-condensable from the reactor top enter the
bottom of high pressure scrubber. Dilute carbamate through HP carbamate
pumps fed to HP scrubbercondensing media in the shell side. NH3 and CO2 get
condensed while bubbling up through the liquid head. A small amount of
uncondensed NH3 and CO2 and the inert leave the HP scrubber through inert
vent valve to LP absorber. CO2 is injected above packed bed for purging so as
to prohibit any explosion that may occur due to presence of H2.

25. 25
Heat of carbamate formation is removed by a closed condensate circulation
system. Carbamate solution formed overflows through a nozzle located above
the ‘U’ tube bundle to autoclave.
LP absorber and scrubbing system/LP Recirculation System
Uncondensed NH3, CO2 and non-condensable from the HP scrubber enter the
bottom of LP absorber. NH3 and CO2 get scrubbed with lean ammonia water
while rising up through the two packed beds. The lean ammonia water is
supplied by process water pump from lean ammonia water tank. A small
amount of uncondensed NH3, CO2 and the inert leave the LP absorber to
ammonia scrubber. Final scrubbing of the vapours is achieved in ammonia
scrubber with lean ammonia water or DM water before being vent to
atmosphere.
It has following stages in which the process is carried out:-
(a) Rectifying column / separator
The urea carbamate solution from the HP stripper is let down to 3.3
kg/cm2a across stripper level control valve. As a result of pressure
letdown, part of the carbamate in the solution is vaporised to NH3 and
CO2 and solution gets cooled from 170° C to 120° C. The liquid vapour
mixture flows into the top of rectifying column / separator. The liquid
vapour mixture is sprayed over the packed bed of rasching rings through
a nozzle and spray breaker in rectifying column.
(b) LP carbamate condensers andseparator
The overhead vapours leaving from rectifying column are introduced at
the bottom of falling film type LP carbamate condenser. Part of the NH3
and CO2 are condensed to form ammonium carbamate. Lean ammonium
carbamate formed in the flash tank condenser is introduced in to the gas
inlet line of the LP carbamate condenser through a sparger by lean
carbamate pumps. The carbamate formed in reflux condenser of
hydrolyser system is also taken top of LP condenser. Provision is also
made to introduce measured quantity of liquid NH3 to maintain NH3/CO2

26. 26
mole ratio. Heat of condensation is removed by condensate circulation
system.
Carbamate solution from LP carbamate condenser overflows into the LP
carbamate separator, which also acts as a suction vesselfor HP carbamate
pumps. The pressure control valve on gas exit line to atmospheric
scrubber and effectively controls the recirculation system pressure by
sending vapors to the atmospheric vent scrubber for further recovery of
NH3.
(c) Carbamate solution recycle
Carbamate solution from LP carbamate separator is recycled to HP
synthesis section via HP carbamate pumps. Carbamate solution at 2.3
kg/cm2g pressure and 74.2° C is pumped by two of the HP carbamate
pumps. Around 35 % of solution is pumped to HP scrubber and the rest
to HP carbamate condenser. Carbamate pumps are reciprocating pumps
driven by variable speed motors via a gearbox.
(d) Flash tank condenser
Vapours from the flash tank separator flows to flash tank scrubberwhere
any residual urea, NH3 is scrubbed with ammonia water supplied by urea
recovery circulation pumps. The vapours leaving the scrubberare sent to
flash tank condenser where remaining NH3 and CO2 are condensed by
cooling water to form lean carbamate solution. Heat of reaction and latent
heat of water formation is removed by circulating cooling water in the
tube side of the condenser. Vapours leaving the flash tank condenser are
sent to atmospheric vent scrubber for further recovery of NH3 or can be
removed by the flash tank ejector when flash tank is operated under
vacuum when pre evaporator section is bypassed. 4 ata steam is used in
the ejector. The air in bleed isolation valve is provided to the flash tank
condenserfor releasing the vacuum when Prilling section is shut down

27. 27
(e) Pre evaporator
The urea solution from the flash tank separator at about 104° C and 1.06
kg/cm2a pressureis flashed to pre evaporator, which is maintained at 0.40
kg/cm2a vacuum pressure. Urea solution is heated up to 98.6° C in two
separate heat exchangers, which are parts of pre evaporator. Temperature
of the exit urea solution is controlled by 4 ata steam control valve
provided on 4 ata steam inlet line. Exit urea solution at concentration of
82.6 % (w/w) and temperature of 98.6° C is drawn to urea solution
storage tank.
(f) Urea solution storage tanks
Two urea solution storage tanks are installed to receive urea solution
tank. Urea solution (82.6% w/w) from the pre evaporator is received in
urea solution tank for onward pumping to the evaporator. Urea storage
tank is maintained under atmospheric pressure. Urea solution tank also
receives recycle solution of evaporation section during start-up and urea
dust dissolved solution from prill cooling system and bagging and from
material handling plant via prill cooling system
(g) Ammonical Water Storage Tank
Ammonical Storage Tank is provided where the condense gases from
carbamate condensers, rectifying column, scrubberetc are condenseand
stored in Ammonical Water Tank where the concentration is of
carbamate solution and ammonia. This Ammonical water is recovered by
passing through Hydrolyser and Desorber and is reutilized. Thus
Ammonical Water Storage Tank is used for the 100% recovery basis in
Urea plant.
Evaporation and Prilling System:-
Urea solution having a concentration of 82.6 % is pumped from the urea
solution tank to the first evaporator separator by urea solution pump. The
evaporator separator operates under vacuum at 0.31 kg/cm2 a. Urea solution is
heated in the shell and tube type heat exchanger with urea solution flowing in
the tubes and 4 ata steam on the shell side. The urea solution is heated from

28. 28
98.6° C to 130° C to achieve urea solution concentration of 95%. The urea
solution from the climbing film single pass evaporatorflashes into the separator
mounted directly on the evaporator. The water vapour together with some
ammonia is separated in the separator by an impingement cone and baffle
arrangement.
Urea solution at a temperature of about 130° C, having concentration of 95%
(w/w) then flows from first evaporator to the second stageevaporator separator.
Second stage evaporator is operated at a pressure of 0.03 kg/cm2a. In the low
residence time single pass evaporator, the urea solution is further concentrated
to over 98.5% urea
melt for Prilling. The urea solution flowing on the tube side is heated up to a
temperature ofabout 140° C with 9 ata steam flowing on the shell side. The urea
solution from the second evaporator flashes into the separator mounted directly
on the evaporator. The overhead vapours from the evaporator separator are
condensed and collected in ammonia water tanks.

29. 29
Prilling tower:-
Prill cooling system and material handling :-

30. 30
Urea prills after discharging from productconveyorflows into the fluidised bed
cooler through inlet nozzle. Atmospheric air is supplied by inlet air fan for
cooling.
During fluidisation on perforated plate of fluidised bed cooler, heat of hot prills
is taken away by air and cooled urea prills at 55° C flows over the weir to
discharge nozzle. Exhaust air along with some fines ofprills and at temperature
of about70° C passes through the exhaust air nozzle to the dustremoval system
unit. Exhaust air is passed throughcyclone separators to remove urea dust. After
removing dust, almost clean air is exhausted to atmosphere by exhaust air fan
through exhaust air chimney. The dust separated in the cyclone separators is
collected in the three silos. From silo dust is transferred to belt conveyor with
the help of rotary valves provided at the outlet of silos. All the silos are
provided with vibrators to make the dustfall easier. Dust from the conveyorbelt
is transferred to dust dissolving tanks.
From the discharge nozzle of fluidised bed cooler, cooled prills at 55° C are
discharged to producttransfer conveyor through two link conveyors.
Neem Oil Coated Urea:-
Neem oil coated urea is used as the government is providing subsidy for so.
Neem oil coated urea has been used as it has many advantages like the nitrogen
decomposition in soil is less rapid compared to traditional urea and black
marketing of urea also curbs down. Neem oil is added after the fluidized bed
into the conveyorsystemand is transported to Silo where it is further transported
to bagging unit and packed in 50kg bags.
Products :
(1) Urea
 Product properties :
 State : Crystalline solid prills
 Chemical formula : NH2-CO-NH2

31. 31
 Molecular weight : 60
 Melting point : 132.7 C
 Specific gravity : 1.33
 Hydrolyses very slowly in ammonia and carbon dioxide.
 Absorbs moisture from the air.
 Urea undergoes a number of reactions of heating about its boiling point.
 At 160 C, it decomposesto yield ammonium biuret and higher
condensation products.
 Longer the urea is held above its melting point, the further reaction
proceeds.
Urea specifications :
 Total nitrogen : 46.3% by wt.
 Moisture : 0.3% by wt.
 Biuret : 0.9% by wt.
 Fe – content : up to 1.5 ppm

32. 32
UTILITY PLANT
Utility plant consists of mainly:-
1. Steam Generation Plant (Boiler)
2. Inert gas plant/Plant & Instrument Air
3. Cooling Tower
4. Demineralization plant (DM plant)
Steam Generation Plant:-
The modern steam generator is an integrated assembly of several essential
components. Its function is to convert water into steam at a predetermined
pressure and temperature. It is a physical change of state, accomplished by
transferring heat produced by combustion of a fuel, to water. Commonly it is a
constant pressure process. The steam generator is a pressure vessel into which
liquid water is pumped at the operating pressure. After the heat has vaporized
the liquid, the resulting steam is then ready either for delivery to the user or for
further heating in a superheater.
At IFFCO-Kalol Plant, a BHEL make boiler of 80 t/h (net) capacity was
commissioned on 5th October’1982 and is in operation since then.
The BHEL boiler is water tube type, bidrum, forced draft furnace. It is oil and/or
gas fired boiler of 80 t/h capacity at 61.5 kg/cm2g pressure and 410+ 5º C
temperature.
Steam:-
Steam is the vaporized form of water. The vapor is commonly visible as cloud
escaping from the spoutof tea kettle in which water is boiling. The water in the
tea kettle produces 1600 times more volume in steam form.
Theseproperties ofsteam, its ability to carry a large amount ofheat and the large
quantity of steam which can bemade from a small amount ofwater, make steam
an ideal substancefor transferring heat conveniently and economically to every
corner of the plant. Another propertyof steam is the way its volume varies with
change in temperature and pressure of the steam.

33. 33
We take advantage of these properties by generating steam at high pressure to
operate steam turbines, drive generator, compressor and pumps. The low
pressure exhaust steam from the turbines is then used for process requirements.
Steam itself will not burn nor will it support combustion and this property of
steam is utilized to purge or remove oil or gas or extinguish a small fire.
The intent of the ensuing discussions is to present the fundamentals and
precautions encountered in steam generation. The fundamentals presented touch
the basics of heat transfer and their respective contribution to steam generation,
furnace details, material selection, fuels etc. The precautions mentioned pertain
to feed water treatment in areas of oxygen removal, alkalinity and scale
formation.
Inert gas plant and plant & instrument air plant:-
At Kalol plant, nitrogen (N2) is used as inert gas. The inert gas (IG) is almost
dry and contains very low level of ‘active’ impurities since the inert gas will
come in contact with various catalysts in ammonia plant in reduced condition.
Ammonia plant also requires hydrogen (cracked gas) to reduce fresh charge of
LTS catalyst. During the plant turnaround and shutdowns of ammonia plant the
fresh catalyst can be reduced using the cracked gas and inert gas generated in
inert gas generation plant, IG thereby saving around 6 to 7 days of startup time
of ammonia plant. Also LTS catalyst can be heated with inert gas during plant
start-up to reduce plant start-up time.
IFFCO Kalol has two independent inert gas generation plants for producinginert
gas (nitrogen gas). In boththe plants inert gas is produced byammonia cracking
process. Inert gas generation plant supplied by M/s. Wellman Incandescent was
commissioned in 1975. The inert gas generation plant supplied by M/s. Indcon
Polymech Ltd, (G-5501) was commissioned in 1994.
In the ammonia cracker, ammonia dissociates at 850 0C into hydrogen and
nitrogen in presence of a nickel based catalyst.
2 NH3 (g) 3 H2 (g) + N2 (g) H = +10.96 kcal/g mol
In combustion chamber, air is supplied so as to maintain O2 slightly less than
the theoretical requirements forreaction with hydrogen to retain slight unreacted

34. 34
hydrogen in the gas leaving the combustion chamber. The combustion reaction
is :
2 H2 (g) + O2 (g) + N2 (g) 2 H2 O (g) + N2 (g) H =-57.798 kcal/g mol
In deoxo unit, the traces ofoxygen react with hydrogen in presenceofpalladium
catalyst.
2 H2 (g) + O2 (g) 2 H2 O (g) H =-57.798 kcal/g mol
Liquid ammonia from ammonia storage tank is received at 7 kg/cm2g pressure
and – 330 C temperatures and is fed to shell side of ammonia vaporizer.
Ammonia vaporizer is having a coil arrangement. In the tube side, hot cracked
gas flows and provides heat for ammonia vaporization. Then vapor ammonia
flows to the ammonia cracker which is electrically heated vessel containing a
Ni-based catalyst. The ammonia dissociates into hydrogen and nitrogen in
presence of Ni-
cracker after passing through the coil of the vaporizer enters the combustion
chamber, where hydrogen is burnt with slightly less than stoichiometric quantity
of air inside a water jacketed combustion chamber.
The gas leaving the combustion chamber passes into contact cooler, where
demineralised water/raw water is used as the coolant. The water leaving the
contactcoolercontains traces of ammonia and goes to jacket cooling water pump
pit.
The nitrogen after cooling passes to the inert gas surge drum for removal of
water and then to the motor driven inert gas compressor where it is compressed
to 7.0 kg/cm2g in two stages. The nitrogen gas then enters the de-oxo unit in
which residual oxygen reacts with hydrogen in presence of palladium catalyst to
give required nitrogen purity. Nitrogen from the de-oxo unit is cooled in shell
and tube type after cooler, dried to -
stored in an IG receiver from where it is distributed to various consumption
points.
Plant and instrument Air:-

35. 35
Compressed air is a major sourceofindustrial power, possessingmany inherent
advantages. It is safe as well as economical, adaptable and can be easily
transmitted. A compressed air plant considered in broader sense consists
essentially of one or more compressors (each with necessary drive and
controls), in-take air filter, inter cooler, after cooler, water separator, air
receiver, inter connecting piping, dehumidifier and distribution network to
carry air to the various points of application. The object of installing
compressors and maintaining the compressed air system is to provide service
air (plant air) and instrument air at the point of application in sufficient quantity
and with adequate pressure for efficient operation of instruments, controls, air
tools & appliances, on-line air masks and for emergency start-up of 0.860 MW
diesel generation set in case its air compressoris not available.
Plant air and instrument air are the same except the moisture content. The
instrument air is dried in dryer to achieve dew point of -40 ºC at atmospheric
pressure. The compressed air is available through two sources i.e.
 High pressure air available from the air compressorofammonia plant.
 Reciprocating air compressorsin compressorarea of utility section.
The compressed air at around 7.0 kg/cm2g pressure is used as plant air and the
header goes to all the consuming points. The compressed air after
dehumidification process is used as instrument air. The instrument air at 7.0
kg/cm2g pressureis supplied to all consuming points mainly forinstrumentation
and controlpurpose.
The normal overall compressed air requirement in the plant is around 1800
Nm3/h which is touching to 3000 Nm3/h during peak demand. Instrument air
receiver has a capacity, lasting approximately 5 to 7 min. in the event of
compressorsfailure so that the plant can be shut down safely.
All the compressors of utility section are integrated. Normally air is made
available from process air compressor of ammonia plant and integrated with
plant / instrument air.
The plant air is supplied to:-
 ammonia plant,
 urea plant,

36. 36
 utility/off sites plant,
 workshop,
 bagging & material handling plant,
 on line air masks and
 Various local connections.
The instrument air is supplied to:-
 Ammonia storage tank,
 Water treatment plant,
 Urea plant,
 Bagging and material handling plant.
 Steam generation plant,
 Effluent treatment plant,
 Cooling towers,
 Inert gas generation plants,
 CO2 compressors,
 Ammonia plant during plant shutdown and
 For emergency start-up of 0.860 MW diesel generating set when its
compressoris not available.
The ammonia plant is self sufficient so far as its instrument air supply is
concerned. During normal operation, ammonia plant does not need any
instrument air from an outside source. However, when the process air
compressoris notin operation, instrument air will be supplied to ammonia plant
from the instrument air compressors ofutility section.
Cooling Tower:-
Principle of cooling tower
The cooling tower is one type ofheat exchanger which cools hot water with air.
It is basically a tower containing treated wood as filling material. Filling
material is piled up in the tower from the distribution basin. Water falls on the
filling and breaks into fine droplets. The function of the filling (internals) is to
increase the contact surface between the water and air. The filling at IFFCO -
Kalol is replaced byV-shaped PVC bars having small slots from woodensplash
bars and are arranged in sucha way that the water entering the distribution trays

37. 37
near the top of the tower is repeatedly broken into fine particles as it descends
through the tower. Fan mounted on top of the tower induces air into the tower
through air inlet louvers, placed on either side of the tower. Across this air flow,
water drops fall through fillings.
Types of cooling tower
Modern cooling towers are classified according to the means by which air is
supplied to the tower and the method of contact between water and air. There
are two types of cooling towers
 Atmospheric and natural draft cooling tower.
 Mechanical draft tower.
The mechanical draft towers is subdivided into two types
 Forced draft towers
 Induced draft towers.
ForcedDraft Towers
Forced draftcooling towers are the oldesttypes of mechanical draft towers. The
fan being located at the base of the tower so that they force air into the sides of
the tower and flows upwards through the falling water and out at the top of the
tower. The air distribution is poor since the air must make a 900 turn while at
high velocity. In forced draft tower the air is discharged at low velocity from a
large opening at the top of the tower. Under this condition the air posses a small
velocity head and tends to settle into the path offan intake. This means that fresh
air is contaminated by partially saturated air which has already passed through
the tower. This condition is known as recirculation and reduces the
performances of cooling tower.
Induced draft cooling tower
This tower efficiently and thoroughly eliminates the difficulties experienced
from the forced draft type. The fan being located at the top of the tower, draws
air through the louvers on all sides near the base of the tower, flows upwards
through the falling water and discharges to atmosphere. In Induced draft tower,
air is discharged through the fan at a high velocity and thus prevents air from
settling at the air intake and thus eliminates recirculation. The higher velocity of

38. 38
discharge of the induced draft tower causes entrainment loss or drift loss of
water.
In these induced draft towers, air flow may be either cross flow or counter
current. At IFFCO-Kalol unit cooling towers are induced draft, cross flow type.
Demineralization Plant (DM Plant):-
Demineralization is the process ofremoving the mineral salts from water by ion
exchange. Only those substances which ionize in water can be removed by this
process. Demineralization use exchange of ion as a method of purification. Ion
exchange is actually a chemical reaction in which mobile hydrated ions ofa solid
are exchanged for ions of like charge in solution. Demineralization process
involves two ion exchange reactions. The cations (positive-ions) such as
calcium, magnesium and sodium are removed in cation exchanger, and anions
(negative-ions) such as chlorides, sulphates, nitrates etc. are removed in anion
exchanger.
Quality of water comparable to that of distilled water is required for high
pressure boiler operation. The presence of silica in such water is most
undesirable, since the silica may permit the formation of boiler tube deposits or
vaporize with the steam and cause turbine blade deposits. It is therefore
necessary for demineralized water to have a very low silica content in order to
be useful for boiler feed water purpose.
For cooling tower make up water, silica is not a critical parameter and therefore
the water outlet of weak base anion exchangers is used as CT make up.
Cation exchange reactions
Reaction in cation exchanger can be represented by the following equations.
Re H + NaCl Re Na + HCl
2Re H + CaSO4 Re2 Ca + H2SO4
2Re H + Ca CO3 Re2 Ca + H2 CO3
Anion exchange reactions

39. 39
The following equation can be used to illustrate the manner in which anion
exchange resins operate.
ReOH + HCl ReCl + H2O
2 ReOH + H2 SO4 Re2SO4 + 2 H2O
Degassing
For removing the carbonic acid formed by the removal of cations of carbonates
a degasseris provided which will remove H2CO3 bythe process ofstrippingwith
air. The reaction is as follows. No additional chemical is used in this process.
H2 CO3 H2O + CO2
Silica removal by strong base anion exchanger
The strongly basic anion exchangers will remove silica, sulphides and
carbonates as well as the other common anions. For this reason, direct silica
removal is possible. The removal of silica by strongly basic anion exchanger
resin can be represented as follows:-
ReOH + H2SiO3 ReHSiO3 + H2O.
(Basic Exc. Resin) (Silicic acid) (Resin silicate) (water).
OFFSITES
Offsite facility mainly consists of:-
1. Ammonia Storage Tanks
2. Narmada Water Treatment Plant
3. Effluent Treatment Plant
AMMONIA STORAGE AND HANDLING :-
(a) 10000 T ammonia storage tank
10000 t atmospheric liquid ammonia storage tank was built by M/s
Vijay tanks and vessels pvt. limited. It is a single wall cylindrical

40. 40
vessel with a fixed self supporting cone roof and insulated with
polyurethane foam (PUF). Its diameter is 30 m and height is 21.5 m.
The tank is provided with refrigeration system and sufficient safety
gadgets.
(b) 5000 T ammonia storage tank
5000 t atmospheric liquid ammonia storage tank constructed by India
TubeMills ltd was installed in the year 1992. It is cup in cup double
wall type, cylindrical vessel with suspended deck on inner wall and
fixed self supporting cone roof on outer wall. The outer wall is
insulated with polyurethane foam (PUF). The spacebetween two walls
remains filled with ammonia vapor which works as an insulator. The
outer shell diameter is 23.29 m and height is 21.74 m while inner
shell diameter is 21.79 m and height is 20.25 m.
(c) Rail tanker loading system
The surplus liquid ammonia from storage tanks is dispatched to IFFCO
Kandla unit through rail tankers. Forloading ammonia into rail tankers,
five loading points are provided. At a time batchoffive tanker wagons,
each having capacity of 32 t can be loaded. Two no. of ammonia
loading pumps each having discharge capacity of 105 t/h at apressure
of 19.58 kg/cm2g are installed. These pumps are also utilized for
supplying liquid ammonia to urea plant as and when required.
(d) Roadtanker loading system
Surplus ammonia is sold to buyers through road tankers. To load
ammonia in road tankers two loading stations are provided. Two
ammonia circulating pumps each having discharge capacity of 10 t
/h at 7.3 kg/cm2a are used for road tanker loading. A flow totaliser
with auto shut off valve as per preset value is provided to facilitate
loading of required quantity of liquid ammonia in road tanker.
(e) Refrigeration system

41. 41
The ammonia storage tanks are fully insulated and designed for
maximum boil off of 0.04 % per day. Vapour pressure of ammonia is
high even at atmospheric condition. To maintain nearly atmospheric
pressure in the tank, the vapour generated has to be condensed. This is
done by taking the generated vapours from storage tank to the
refrigeration system where the vapours are compressed, liquified and
returned to the tank in liquid form
(e) Flare stacks
Normally ammonia vapour generated from ammonia storage tank,
vapour released from ammonia rail and road tankers during filling is
taken to refrigeration system. When refrigeration system is under
maintenance or sufficient refrigeration compressors are not available
to take care of vapours generated or for time being vapours generation
is high, ammonia vapour is released to flare stack and burnt.
NARMADA TREATMENT PLANT:-
The Narmada water is supplied from Jaspur village to Narmada water (raw water
reservoir) at IFFCO-Kalol through pumps. The raw water is stored in raw water
reservoir and is further pumped up in stealing chamber where it is mixed with
Chlorine and PAC (Poly Aluminum Chloride) to remove smell, turbidity and
any contaminants and is further passed through flash mixer and poured in
Clariflocculator. The sediments collected in Clariflocculator are stored in waste
pit the water from the Clariflocculator is now passed in another three way
chamber where sand, gravels are present. Sand, gravels, concrete acts as a filter
and filters the water into clear water. This clear water which free from sediments
and contaminants is stored in clear water sump and transported to various places.
During choking of sand and water backwashing is done with clear water for
efficient working of sand. The waste is collected in waste and sludge pit and the
sludge is used in fields or disposed off. Out of six pumps three pumps are
operational and others are as standby for supply of clear water. The clear water
is transported to following places:-
 Cooling Tower
 DM water plant
 Domestic purposes at IFFCO Township Kasturinagar.

42. 42
Thus Narmada water is treated and used in IFFCO-Kalol facility.
EFFLUENT TREATMENT PLANT(ETP):-
(a) Effluent treatment & disposal
The effluent waste generated from the plants before discharging
outside the IFFCO Kalol premises shall confirm statutory regulations
imposed by the State and Central Government Pollution Control
Boards. Under effluents control & disposal system, the total liquid
effluent generated from the different plants is segregated in two
categories viz. strong effluent and bulk effluent.
This effluent is collected either into strong effluent storage tanks or
bulk effluent tanks. Open channels water is collected in bulk effluent
tanks. Weak effluent segregated from the water treatment plant is
collected in weak effluent tank-B and same is allowed to mix in bulk
tank-A for better mixing and neutralization.
Water from urea plant drains and washings is collected in separate
tanks known as balancing ponds and diverted either to bulk or strong
effluent as per its analysis.
(b) Bulk effluent treatment and disposal
Effluent water containing comparatively very low concentration of
pollutants is called bulk effluent. The effluent from following sources
is collected in bulk effluent storage tank.
 Water treatment plant with low concentration of salts
 Inert gas generation plant
 SPC / polisher unit regeneration
 Cooling water blow down
 From hydrolyser system during upset condition.
 Sand filters backwash
 Oil separator

43. 43
 Domestic effluent.
 HCl fumes scrubber’s water
The pH of the bulk effluent is continuously recorded by pH analyzer.
pH is controlled by dosing H2SO4 or 2 % spent NaOH collected from
regeneration of SBA units in water treatment plant. Samples are also
analyzed in laboratory at different intervals. Bulk effluent is
discharged outside IFFCO premises once the analysis report confirms
to the permissible limit set by Gujarat Pollution Control Board
(GPCB).
(c) Strong effluent treatment and disposal
The concentrated effluent from water treatment plant is collected in
strong effluent tank and discharged to solar evaporation lagoons inside
the IFFCO premises with the help of strong effluent pumps.

44. 44
CONCLUSION
I am very grateful to IFFCO-KALOL, for giving me the opportunity to get
a practical overview of the fully functional chemical plant. The experience
of gaining practical knowledge was really great and will surely be of great
help in my future. The environment of IFFCO-KALOL is very decent and
highly motivating, as all the employees and officials helped me in every
possible manner to gaining the knowledge about plant and processes
carried out with great enthusiasm. I have gained a lot of experience, apart
from academics and technical point of view. Once again, I am heartily
thankful to all the employees, officials and fellow trainees, who contributed
in making my internship at IFFCO KALOL, more interesting, more fruitful
in any possible way.
Thank You.
Daxit Akbari

45. 45
REFERENCES
 Website- www.iffco.coop
 Ammonia plant Iffco-Kalol manual
 Google Images IFFCO-Kalol
 Urea plant Iffco-Kalol manual
 Fire and Safety Iffco-Kalol Manual
 Utility Iffco-Kalol Manual
 Offsite Iffco-Kalol Manual
Plant Operators and Technicians