UREA TRAINNING explains about urea manufacturing

urea manual

2. FERTILIZER
Fertilizer is a substance, organic or inorganic, natural or
synthetic which supplies one or more chemical
elements required for plant growth.. The essential
elements which help in plant growth can be divided in to
three groups:
Primary nutrients (Supplied through fertilizers)
Secondary nutrients (Supplied through fertilizers)
Micronutrients(Supplied through soil)

3. FERTILIZER
17 nutrient elements are recognized at present as being
essential to all plants for their growth and development:
Carbon, hydrogen, oxygen (From air and soil water )
Primary nutrients
Secondary nutrients
Micronutrients

4. PRIMARY NUTRIENTS
Nitrogen (N -UREA)
Phosphorous (P –P2O5)
Potassium(K –K2O)
Represented as NPK –

5. SECONDARY NUTRIENTS
Calcium
Magnesium
Sulphur
Added in required quantities to NPK fertilizers

6. MICRO NUTRIENTS
Boron Chlorine
Copper Nickel
Iron
Manganese
Molybdenum
Zinc
SUPPLIED BY THE SOIL OR ADDED TO THE SOIL AFTER
TESTING

7. UREA (46.0.0)
PRODUCT NAME: UREA 46% (CARBAMIDE) FERTILIZER
ACTIVE INGREDIENT: Nitrogen 46%
CHEMICAL FAMILY: Amides
MOLECULAR FORMULA: CH4N2O (NH2COONH2)
SYNONYMS: Carbamide, carbonyl diamide

8. PHYSICAL PROPERTIES
(A) Molecular weight 60.06
(B) Melting point 133.0
(C) Density (gm/cm
3
) 1.335
(D) Bulk density (kg/ m
3
:
(I) Prilled 740
(II) Granular 720-770

(E) Solubility (gm/100gm of water)
at 20°C 108.0
at 100°C 733.0
(F) Angle of repose 30°

9. CHEMICAL PROPERTIES
Urea decomposes thermally to form an Isocyanic acid-ammonia
gas mixture at temperature of 330-450 degrees centigrade. The
Isocyanic acid is then converted in to melamine and
carbondioxide.
During urea synthesis, biuret formation occurs in the
evaporation steps which convert the product solution to solid
end product. Biuretis the condensation product of two
molecules of urea (NH
2-CO-NH-CO-NH
2) and if the percentage
of biuret exceeds a certain limit, its toxicity goes up.

10. UREA PROCESS
•Process Know-how by M/s SNAMPROGETTI, Italy
•Detailed engineering by PDIL, Baroda
PLANT FIRST PRODN COMMERCIAL PRODN
DATE DATE
U 11 20th Oct., 1984March,1985
U 21 18th Dec., 1984June, 1985
U 31 30th Mar., 1985June, 1985

11. 1
ST
REACTION :-
2 NH
3+ CO
2 NH
4COONH
2
(L) (G) (Ammonium Carbamate) (lg)
1) Exothermic
2) Fast
3) Reversible
4) 100% Conversion
2
ND
REACTION :-
NH
4COONH
2 NH
2CO NH
2+ H
2O
1) Endothermic
2) Slow
3) Reversible
4) Conversion is not 100%
MAIN REACTIONS (UREA SYNTHESIS)

12. Biuret formation :
NH
2CO NH
2+ NH
2CO NH
2 NH
2CONHCO NH
2+ NH
3
(Biuret)
Biuret formation is favored by following factors :
1) High temperature of Urea melt,
2) High concentration of Urea
3) High residence time of Urea melt.
SIDE REACTIONS (BIURET FORMATION)

13. APPLICATIONS
95% OF UREA IS CONSUMED AS `FERTILIZER' IN INDIA
INDUSTRY APPLICATIONS:
Chemical industry
Chemical-technical industry
Wood-processing industry
Plastics industry
Mineral oil industry
Paper industry
Textile industry
Biotechnological processes
For removing NOx from flue gases
De-icing at airports
Pharmaceutical industry
To manufacture the cattle feed

14. PACKING AND SAFETY
PACKING
Domestic: Supplied in 45 kg poly-propylene bags / 500kg pp bags as
technical urea.
Export: Subject to Central Govt. License -Supplied in 45 / 25 kg
HDPE double laminated bags with LDPE liner.
SAFETY: Urea is not subject to any labeling restrictions. It should be
transported and stored away from nitrites and nitrite-containing salts.

15. USES OF UREA –FERTILIZER GRADE
Almost 90% is used in direct application as fertilizer and called fertilizer grade
urea
FCO –STANDARD
White Free Flowing -
Total Nitrogen (Dry basis)(% by wt. min).46.00
Moisture (% by wt. max).1.00
Biuret (% by wtmax). 1.50

Size:90% of the material shall pass through 2.8 mm IS Sieve and Not less than
80% by weight, shall be retained on 1.0 mm IS sieve.
 Over size (Above 2.8 mm) (% by wtmax.) 10.00
 Undersize (Below 1.0 mm)(% by wtmax.) 10.00

16. Total Nitrogen (Dry basis)(% by wt. min)46.00
Moisture (% by wt. max)0.5
Biuret (% by wt max)0.8
Free Ammonia (% by wt) 0.015 to 0.22
Iron (as Fe ) (% by wt. max.) 0.0002
Ash (% by wt. max.)0.002
p
H
of 10 % solution 7.5 to 10

Size:Prill, which shall pass, IS sieve 200 and not less than 80 % by weight
of it shall be retained on IS sieve 100.
USES OF UREA –TECHNICAL GRADE

17. HISTORY DEVELOPMENT OF UREA TECHNOLOGY
UREA was 1
st
synthesized in 1824 from ammoniaumcynateby WHOLER
HCNO + NH3 = NH4CHO (AMMONIUM CYNATE)
CYNIC ACID)
NH4CHO = NH2CONH2 (UREA)
In 1870 BASSAROW produced urea by dehydration of ammonium carbamate which is
basis of present commercially process. There was no break through in urea production
commercially till 1920
1
st
commercial production of urea was in 1922 by DUPONT from nitro lime at plant in
Canada.
CaCN2 + 3H2O = NH2CONH2 + Ca(OH)2
(Calcium cyanamid)
The process route which is adopted by the present day plants, was achieved by I.G. Farben
in 1922 at plant in Germany
Co2 + 2NH3 = NH4COONH2 = NH2CONH2 + H2O
Earlier urea were based on once through process
In 1935 DU Pont built at Belle west Virginia Imperial Chemicals industries USA
In 1939 MITSUI CHEMICALS JAPAN began production of urea
In 1950 world urea production was less than 1 lakh ton /annum

18. MAJOR PROCESS FOR UREA USED IN SIXTIES
CONVENTIONAL PROCESS
CHEMICO (BRITAIN)
INVENTA (SWISS)
MONTECTANI (ITALY)
POCHINERY GRACE (FRANCE)
STAMICARBON (NETHERLAND)
TOYOKOAZTSU (JAPAN)
DUPONT (CANADA)
CPI ALLIED (USA)

19. DEVELOPMENT SINCE SIXTIES
SNAMPROGETTI STAMICARBOM TEC –MTC (JAPAN) MONTEDDISON
1963 1930 1947 1948
ONCE THROUGH CO2 STRIPPING PROCESS ONCE THROUGH ONCE THROUGH
NH3 stripping PARTIAL & TOTAL RECYCLE
1990
INTODUCTION OF
BIMETALLIC STRIPPER
PRECONCENTRATOR
HEAT RECYCLE
HET
CENTRIFUGAL NH3 PUMP
2004
INTRIDUCTION OF Zr
Zr STRIPPER
OMEGA BOND STRIPPER
5000 TPD PLANT AT OMAN
1964
CO2 STRIIPING PROCESS
1991
POOL CONDENSOR
CO2 STRIPPING
1992
POOL REACTOR
2002
4500 MTPD PLANT
1950
TOATSU PARTIAL
RECYCLE
1958
TOYO-KOATSU TOATL
RCYCLE, 1966 (MTC)
1969 (TOTAL RECYCLE
“C”IMPROVED PROCESS)
1980 (TOTAL RECYCLE D)
1983 (CO2 STRIPPING
PROCESS)
TEC-MTC-ACES
1996, ACES-21
VERTICAL CONDENSOR
(PLANT AT INDINESIA)
1958
TOTAL RECYCLE
1968
MONTEDISON LTEST
TOTAL RECYCLE
1981
“IDR”(ISOBARIC DOUBLE
REYCLE) CO2, NH3 BOTH

20. Currently used Urea technologies
1. Snamprogetti (Saipem) -107 plants
2. Stamicarbon –140 plants
3. TEC –ACEs –16 plants

21. RCF UREA PLANT
1984 -1500 * 3 = 4500 MTPD
2002 -1725 * 3 = 5175 MTPD
(UOP, HIGH CAPACITY CARBAMATE CONDENSER AND
BIMETTALIC STRIPPER)
2013 -1900 * 2 + 2300 = 6100 MTPD
(AMMONIA PREHEATER, ADDITIONAL P1 AND P2, VACCUM
SYSTEM)
ENERGY HAS REDUCED DOWN TO 5.8GCAL/MT

22. SNAMPROGETTI,
ITALY

23. SNAMPROGETTI UREA TECHNOLOGY
Eastablished in 1956in Milan, Italy, has more than 45 yrs of sucees in
urea projects implementation and production , all over the world.
To date more than 107 urea plants have been built or are under
construction using this technology
Every single day, these plants produce 132000 tons of nitrogenous
fertilizers.
The resulting technology was completely different from that
snamprogetti’s competitors and are based on intelligent and
interesting principles, such as the use of excess of NH3 to avoid
corrosion and promote the decomposition of carbamate not
converted into urea.

24. Snamprogetti Urea Worldwide share
Snamprogetti plants = about 107 worldwide (40% of
total nos. of UREA plants in world)
70% of plants are built in last 10 years
About 30 plants in India
Highest capacity plant (SINGLE UNIT) 5000 MTPD –
Oman Indian Fertilizers CO-OMIFCO, OMAN

25. SNAMPROGETTY (SAIPEM PROCESS), ITALY
(Total Recycle NH3 Stripping Process)
Process Description:
Urea production process takes place through the following
main operations:
a) Urea synthesis and high pressure recovery
b) Urea purifications and low pressure recovery
c) Urea concentration
d) Urea Prilling
e) Waste water treatment

26. RECOVERY
UREA PROCESS
BFW
UREA
BAGGING
WTP
MT-4
WASTE
WATER
MEDIUM
PRESSURE
LOW
PRESSURE
VACUUM
HIGH
PRESSURE
NH
3
CO
2
2NH
3+ C0
2 NH
4COONH
2
NH
4COONH
2 NH
2-CO-NH
2+ H
2O
160 ATA 16 ATA 4 ATA 0.3 & 0.03 ATA
1.5 ata

27. SPECIFICATION OF PRODUCT
UREA
 SIZE ( 1mm -2.4 mm) - >95.0 %
 Moisture (max) - 1.0 %
 Biurrate (max) -1.5%
 NITROGEN –46%
BOILER FEED WATER
 Ammonia -< 4.0 ppm
 Urea -< 1.0 ppm
 Conductivity -< 20 micro mhos
 Silica -< 0.02 ppm

28. UREA RECORDS
Daily highest production: 6325 MT (09/01/14)
Monthly highest production: 1,92,715 MT (july14)
Yearly highest production: 2178010 MT (2014-15)
Lowest yearly energy consumption :
5.869 MKcal/ MT Urea (2014-15)
Lowest Daily energy consumption :
5.374 Mkcal/ MT Urea (30-01-2019)
Lowest Monthly energy consumption
5.427 Mkcal/ MT Urea (Jan-2019)

29. MV-9
DRAIN
BCL
LPTGEAR
BOX
MCL
HS
HIGH PR. STEAM
HPT
BCL III
STAGE
BCL IV
STAGE
MV-16
PC290
LC068 LC065
LC073
DRAIN
DRAIN
DRAIN
CW
CW
159kg/cm
2
MS EXTRACTION
MS INT. CONNN.
TK1 CONDENSATE
MV-16
MV-17
CO2 FROM B.L.MV-18
R-1 MV8
ATM
PC003
FR001
PASSIVATION
AIR
HC062
HC063
ATM
HC061
E-24E-25
E-26
ANTI-SURGE CV
LC061
MCL II
STAGE
MCL I
STAGE
0.37kg/cm
2
40
o
C
156-161Kg/cm
2
CW
26.83KNM
3
/HR
28-34KNM
3
/HR
0.37-0.4Kg/Cm
2
96kg/cm
2
90-100Kg/cm
2
TI067 122
0
C
PC075 159 Kg/Cm
2
PI073 80Kg/Cm
2
TC066 50
0
C
81-85Kg/cm
2
213
0
C
196-207
0
C
TI064 45
0
C
FR246 70.20 T/HR
30.20KNM
3
/HR81-85Kg/cm
2
28-35 KNM
3
/HR
PI069 18.13 Kg/Cm
2
AR061 0.35%
PI067 5.37kg/cm
2
TI062 45
0
C
40-46
0
C
4.4-5.5Kg/cm
2
157-160Kg/cm
2
39-46
0
C
76-85 T/HR
24kg/cm
2
TI235 318
0
C
20-22Kg/cm
2
310-335
0
C
FC061 1305 NM
3
/HR
480-600NM
3
/HR
43-50
0
C
CO2 COMPRESSOR
STAGE 1 2 3 4
Pressure
ata
0.7/5.61 5.37/ 21 19.5/82 80/160
Temperature
O
c
40/183 45/182 45/213 50/110

30. INCREASE IN C02 SUCTION PREESURE
FROM 0.4 TO 0.7 KG/CM2 g
STEAM SAVING
HELPED IN INCREASING PLANT LOAD

31. P-1A
P-5 A/B
R-1
LC106
HC034
PC012 219 Kg/Cm
2
HC031
HC034
HC032
P-1B
P-1D
HC035
AMMONIA FEED PUMP (P1)
231-235Kg/Cm
2
V-1
17-22 Kg/Cm
2
24.1 Kg/Cm
2
P-1C
HC033
E60E60
V-1
TC103
C-1
INSTALLATION OF ADDITIONAL P1 IN U31

32. HP SECTION
R
E
A
C
T
O
R
K-1
ME-2ME-14
CARBAMATE
SEPARATOR
MV-1
CARBAMATE
CONDENSER E-5
P-1
MV8
M
MIXER
E-51
E-2
P-2
C1
HC006
HV3
LC002 HV5
HV2
HV8
PC007A
HV1
PC007B
M PC012
LC005A
LC005B
V2
LW
STRIPPER
R-1
E-1
MV-4
STRIPPER COND.
SEPARATOR
ME-1
TR002 174
0
C
TR003 188
0
C
188-190
0
C
174-176
0
C
PC007 145Kg/Cm
2
143-144 Kg/Cm
2
TI071 158
0
C
156-159
0
C
TR004 120
0
C
115-122
0
C
TR007 203
0
C
202-203.5
0
C
TR008 190
0
C
188-189
0
C
HP PRESS = 145 KG/CM2
E-60
ME-3
E -8
TT559 70
0
C
TI560 75
0
C
T1132 126
0
C
TI112 12
0
C

33. INSTALLATION OF ADDITIONAL P1 and P2
P1OF SAME CAPACITY 65 M3/HR
Required for high load
Reduction in vibration
Increase in equipment life
P2CAPACITY INCREASED FROM 58 TO 99 M3/HR
BOOSTER PUMP IS PROVIDE TO ELIMINATE CAVITATION
EFFECTS ON MAIN PUMP

34. NH
3 LIQ
FROM P1
CO
2 GAS FROM K1
R1 OVERFLOW LINE
15 SIEVE TRAYS
SPARGERS
R1 -REACTOR
SOLUTION TO
STRIPPER
Type :Vertical Plug Flow Reactor
Fluid :NH3, CO2, H2O, Carbamate, Urea
Op/Design Press: 153-159/169 ( kg/cm2)
Op/Design Temp : 186-189/200 0C
I.D. of Reactor: 2350 mm.
Height of Reactor: 40000mm.
Volume of reactor: 173.5m3
Shell thickness : 120 mm (CS) 8 layers of 15 mm
Lining : 7 mm thk(min.)–SS 316LM
Sieve tray : 10 +5new =15
(five more sieve trays are added in optimization.)
Distance of last tray from bottom T.L. : 3500mm
Distance of 1st tray from top T.L.: 1500mm
Inter tray spacing: 2500mm
Tray diam: 2335mm
Tray thickness : 7mm
Cleat thickness: 7mm
Shell and heads: C.S with lining of
AIS316L Mod R-516
Internals : 2RE69 U25/22/2-Cr Ni Mo
Weight :350/530 MT ( Empty/filled)
Name of supplier: KOBE STEEL.
R1

35. Number of holes
From Top Tray Number Previous Modified trays Hole ID mm
TOP TRAY 1 852 852 8
2 852 852 8
3 852 852 8
4 852 852 8
5 852 852 8
6 852 1704 8
7 852 1704 8
8 852 1704 8
9 852 1704 8
10 852 1704 8
11 1704 1704 8
12 1704 1704 8
13 1704 1704 8
14 1704 1704 8
BOTTOM TRAY 15 2556 2556 8

36. REACTION KINETICS
2 NH
3+ CO
2 NH
4COONH
2 NH
2CO NH
2 + H
2O
(L) (G) (Ammonium Urea Water
Carbamate)
Follows LE Chatelier’sprinciple
High temperature (188-190 degC)
High pressure (160 kg/cm2)
High residence time
High N/C ratio (3.3 –3.6)
Low H/C ratio (0.5-0.64)
CO2 is limiting reactant
R1 efficiency = 61-62 %

37. MP CONDENSATE
TO E2-MP DECOMPOSER
HV3
HV5
M
LC2
TO E51
PRE DECOMPOSER
PASSIVATION
AIR FROM K3
PC14
MP STEAM
EXPANSION
BELOWS
MALE TYPE
FERRULES
BIMETALLIC TUBES
VAPOR RISERS
Make : L&T.
Whether Insulated or not: Insulated (75mm)
Type : Vertical bimetallic tube
falling film evaporator
Volume :
SHELL
MOC : Carbon steel
Thickness :
Liner : 6 mm
316LM 25/22/2 Cr Ni Mo
Fluid :MP Steam
Op / Design pressure : 17-23/28.6 kg/cm
2
Op / Design Temp degC : Inlet 200-220/230,
Outlet 200-220/230
FALLING FILM
E1 -STRIPPER
VAPORS VAPORS VAPORS VAPORS
VAPORS COMING
OUT
LIQUID INLET

38. STRIPPER –BIMETTALIC TUBES
0.7 mm ZIRCONIUM
2 mm SS
2RE69
25.4 mm O.D.
Tube side Fluid
Urea soln., NH
3, CO
2, H
2O
Operating and Design pressure
Tube -147/162.2 kg/cm
2
g
Operating and Design Temp
Tube-Inlet-202-205, Outlet-230degC
Length of tube 5500 mm
No of tubes 2584 mm
Tube sheet C.S 6mm
Liner 6mm Cr-Ni-Mo 25-22-2
Total surface available
For heat transfer 893M
2
No of baffles 9
Baffle spacing 500 pitch

39. STRIPPER –MALE TYPE FERRULES
VAPOR OUTLET
TAPERED PORTION FITS
INSIDE THE TUBE
LIQUID INLET THROUGH
TANGENTIAL HOLES

40. ITEMS Old stripper New stripper
No of tubes 2966 2584
length 4500mm 5500mm
Tube material titanium 2RE69+zR
SURFACE AREA 838.6 M
2
893M
2
Tube ID/OD 20mm 20mm/25.4mm
Tube thickness 3.5mm 2.7mm (2mm+0.7mm)
Ferrule Details
fitting
Female type Male type
Passivation
Not required Required
Before UOP (208 degC) After UOP (204 degC)

41. DECOMPOSITION STRIPPING
PRINCIPLE If carbamate is converted into NH3 & CO2
gases by reducing pressure and increasing heat
of the solution, it is called decomposition.
HEAT is a driving force.
If carbamate is converted into NH3 & CO2 gases
by reducing partial pressure of one of the
components (that of CO2 in case of NH3
stripping) without changing the total pressure ,
it is called stripping. Partial pressure is a driving
force.
DELTA P w.r.t
REACTOR
Delta P is more than Stripper .
Differential pressure solution flashed due to
high difference of pressure.
No Delta between Reactor and Stripper, however in
Saipem process there is small delta P.
STAGES Decomposition is favoured by low pressure but as
decomposition products are to be recycled back
to reactor it will require energy for this step. Also
at low pressure more water is evaporate during
decomposition and this water would enter the
urea reactor along with recycle stream and will
adversely affect the conversion. Thus if the
decomposition is carried out in single stage near
atmospheric pressure the Carbamate formed
during recovery at the same pressure carry a lot of
water. considering these factors, decomposition
is carried out number of stages.
In stripping process the 1st stage decomposition
and recovery is done at the reactor pressure which
permit heat to be recovered at high level and also
results in saving the power for returning the recycle
streams to the reactor .however in Saipem process
there is difference in pressure in Reactor and
Stripper, so additional advantages of deferential
decomposition.

42. CARBAMATE CONDENSOR E5
TO MV1 SEPARATOR CONDENSATE TO V2
FROM E1 STRIPPER
LS TO HEADER
LC5B
LC5A
KETTLE TYPE REBOILER
Original design have two E5’s, but due to frequent tube leakages because of dry
running of tubes, one E5 was removed. Later it was replaced with high capacity E5.
ITEMS OLD NEW
Nooftubes 1288 1643
Length 12000mm 12296mm
SurfaceAREA 1850M
2
2360m
2
Liner 2RE69
TubeMeterial ASTMA213TP/316L(MOD) SA21MUNSS31050

43. AMMONIA PREHEATER
Heating the Ammonia sent to Reactor, up to
about 70°C, will enhance the HP Loop overall
performance achieving an estimated saving
of MP Steam to theStripper of about 30 –35
kg/h per tonn/h of urea product
The E-8 duty reduction immediately leads to
a CW saving of 6600 -7550 kg/h per
tonn/h of urea product
RUPTURE DISCS ARE INSTALLED AT E60
O/L TO E8
E8
85 DEG
MV3
130 DEG
P1
25 DEG
R1
70 DEG

44. MP SECTION
LC003
E-7
CW
CW
P-2
E-9A
MP CONDENSER
P5
P7
LC103
TC103
FROM V1
FROM C3
V-3
LC102
P-4 A/B
P-3 A/B
TC105
TC101
LC101
LC 679
MP
ABSORBER
C1
E-51
E-5
MV-4
MV-1
TC102
MS
MP DECOMPOSER
MV-3
PR101 17 Kg/Cm
2
TC102 158
0
C
TC101 80
0
C
TR102 43
0
C
43-45 PR112 17.6Kg/Cm
2
FC034 58 M
3
/Hr
52-60 M
3
/Hr
TI106 80
0
C
78-82
0
C
MP PRESS = 16 ATA
E-2
MV-2
LC191
ME-2
P-51 A/B
E-14
E-41
MV-52
ME-3
V3
HV102

45. MP SECTION
AMMONIA RECEIVER TANK
V1
P-1 A/B/C/D
C1
C1
C1
CW
CW
ME15
E21
FC103
LC106
CW
CW
P-5 A/B
PC108A
LC103
P-7 A/B
C3
E-11
E-9A
E-9B
MP INERT
WASHING TOWER
TR102 43
0
C
43-45
0
C
TI113 8
0
C
1-10
0
C
FR104 71.43 M
3
/Hr
TI111 37
0
C
TI116 50
0
C
15.5-17 Kg/Cm
2
TI114 55
0
C
FR106 1.08M
3
/Hr
E8
SGP
PC108B

46. LP SECTION
ME-2
MV-52
CW
CW
MV-52
LP DECOMPOSER
LP CONDENSER
E-21
FC131
V-8
LC161
P-15 A/B
TC101
LC131
CARBONATE SOLUTION TANK
V3
P-3 A/B
COND.
POT
LC136
CW
LC
LS
TC131
ME-15
PC133 3.5Kg/Cm
2
TI132 125
0
C
127-133
0
C
PR132 4.5Kg/Cm
2
TC131 138
0
C
137-140
0
C
TI133 43
0
C
37-44
0
C
3.6-4.1Kg/Cm
2
TI134 43
0
C
FR166 7.53M
3
/Hr
MP PRESS = 4 ATA
MV-3
ME-3
E-3
P-1
R-1
E-60
NH3 PREHEATER
E-17
E-8

47. PRE DECOMPOSER AND PRE CONCENTRATOR
VACUUM
PRECONCENTRATOR
MP
PREDECOMPOSER
MV-51
E1
E5
E-51
MP DECOMPOSER
VAPOUR SEPARATOR
MV2
E-52
ME-52
ME3
P3
E7
MS
LS
E41
MV-52
ME-52
E-14
P-51 A/B
EJ-51
(PC190)
LC192
LC191
TI193 102
0
C
STEAM SAVING 120 KG/HR

48. REVAMPED VACUUM SECTION
I STAGE
VACUUM
SEPARATOR
II STAGE
VACUUM
SEPARATOR
LS
V6
CW
CW
PC141 0.03
Kg/Cm
2
LC135
BOOSTER EJECTOR
P-51
P9
V5
COND.
POT
LS
TC132
130
0
C
LC134
TI193 102
0
C
108-112
0
C
M
V
6
ME4V6
CW CW
TI137 128
0
C
LS
TC133 140
0
C
TI142
136
0
C
PC140 0.3 ATA
0.4-0.7Kg/Cm
2
0.04-0.07Kg/Cm
2
1
ST
STAGE PRESS = 0.5 ATA
2
ND
STAGE PRESS = 0.3 ATA
3
RD
STAGE PRESS = 0.03 ATA
P-8 A/B
ME8
CW
CW
M
V7
E42-AN
V6
EJ-9N EJ-2AN
EJ-2
COND.
POT
ME5
V2
ME6 V6
CW
CW
MV-52
P-51
PC191 0.3
E 42
E 41
E 41N
E 15
E 14

49. PRILLING SECTION
P-8 A/B
LS
E-52
MT-1
MT-3
MT-4 (COMMON CONVEYOR BELT)
SCRAPPER
PRILLING
BUCKET
P-9A/B
V5
UREA SOLUTION
TANK
ME-8
(ME-10)
PRILLING
TOWER
E14
HV-132B
HV-132A

50. PRODUCT QUALITY CONTROL PARAMETERS
BUCKET RPM
PRILLS TEMPERATURE
FINAL SOLUTION (ME7) TEMPERATURE
VACUUM MAINTAINED
BIURET FORMATION (REPROCESSING OF RECYCLED UREA)
MOISTURE CONTENT (PT LOUVERS ADJUSTMENT)

51. UREA CONCENTRATION AT DIFFERENT STAGES
REACTOR (R1) 33%
STRIPPER (E1) 47%
MP DECOMPOSER (E2) 64%
LP DECOMPOSER (E3) 70%
PRE CONCENTRATOR (E52) 85%
1
ST
VACUUM SEPARATOR (MV6) 95 %
2
ND
VACUUM SEPARATOR (MV7) 99.7 %
PRILLING SOLID PRILLS

52. WASTE WATER SECTION I
DISTILLATION TOWER -C2
ME15
ME-5
ME-4
LC TO
V2
LS
COMMON HDR
WTP
E19
DRAIN
LS
E19
ME15 V8
E17
C2
V6
E-16
LC166
LC164
FC161
FC163
AV163D
FC162
R2
DRAIN
AV203
PC165
WASTE WATER TANK
P16 A/B
P18 A/B
P14 BP14 A
DISTILLATION
TOWER
C2 REBOILER
C2 OVER HEAD
CONDENSER
C2 REFLUX
ACCUMULATOR
33
RD
TRAY
E-18 A/B
E-20 A/B
CW
CW
WW PRESS = 2 ATA
ME-6
C4 -E12

53. HYDROLYSIS REACTION KINETICS
NH
2CO NH
2+ H
2O 2 NH
3+ CO
2
Follows LE Chatelier’sprinciple
High temperature (225 degC)
Low pressure (25 kg/cm2)
High residence time
low NH3
high STEAM
UREA is limiting reactant

54. WASTE WATER SECTION II
HYDROLYSER -R2
P14
C2
MS
R-2
C2
ME15
E-8
P-15A/B
V8
LC161
PC170
LC168 /
TC168
FC165
PC165
C-2
E-19A
E-17
E-19B
CW
CW
TC161
C2 OVER HEAD
CONDENSER
HYDROLYSER
C2 REFLUX
ACCUMULATOR
HYDROLYSER
PREHEATER

55. Evaporation vs. Boiling
Evaporation and Boiling are two processes that are looked upon often without difference. Strictly
speaking there is difference between the two processes. Evaporation occurs on the surface of the liquid
whereas boiling occurs in the liquid in its entirety. This is the main difference between evaporation and
boiling.

There is difference between the two states in terms of the time taken too. Boiling takes place very
quickly and swiftly too. On the other hand evaporation takes place slowly and gradually. This is a very
important difference between the two processes.

In short it can be said that evaporation is a gradual vaporization of a liquid on the surface whereas
boiling is a rapid vaporization of a liquid only when it is heated to its boiling point. It is interesting to
note that the boiling point is reduced when the pressure of the surrounding atmosphere is reduced.

One of the differences that are clearly visible in the two processes is that you would find the formation of
bubbles in boiling. On the other hand you do not find bubbles in evaporation. Another important
difference between evaporation and boiling is that evaporation is the process that occurs at any given
temperature. On the contrary boiling is the process that occurs only at the specific temperature called the
boiling point.

56. Bulk density & angle of repose
1.Bulk densityis an indicator of soil compaction. It is calculated as the dry weight of soil divided by
its volume. This volume includes the volume of soil particles and the volume of pores among soil
particles.
2.When bulk granular materials are poured onto a horizontal surface, a conical pile will form. The
internal angle between the surface of the pile and the horizontal surface is known as the angle of
repose and is related to the density, surface area and shapes of the particles, and the coefficient of
friction of the material. Material with a low angle of repose forms flatter piles than material with a
high angle of repose.
3.The melting point (or, rarely, liquefaction point) of a substance is the temperature at which it
changes state from solid to liquid at atmospheric pressure. At the melting point the solid and liquid
phase exist in equilibrium. The melting point of a substance depends on pressure and is usually
specified at standard pressure. When considered as the temperature of the reverse change from liquid
to solid, it is referred to as the freezing point or crystallization point.

57. Neem coated urea
It has been scientifically established that Neem oil serves as an effective inhibitor if coated on
Urea. Thus, the benefits are as follows: Neem coating leads to more gradual release of urea,
helping plants gain more nutrient and resulting in higher yields.
Thus, the benefits are as follows:
Neem coating leads to more gradual release of urea, helping plants gain more nutrient and
resulting in higher yields.
Lower underground water contamination due to leaching of urea.
Neem serves as a natural insecticide
Collection of neem seeds is needed for manufacturing of neem coated urea. This would generate
employments in rural areas.
Neem-coating will help check heavily subsidized urea’s pilferage to chemical industry and other
uses such as making of adulterated milk.

58. STEAM AND CONDENSATE (WASHING) NETWORKS
STEAM NETWORK
1. HP STEAM (100 KG/CM2, 500 DEGC)
TURBINE, HYDROLYSER, MS PRDS
2. MP STEAM (24 KG/CM2 SATURATED)
PROCESS HEATING, E1, E2, E51, LS PRDS, TURBINE EJECTORS
3. LP STEAM (4.5 KG/CM2, SATURATED)
PROCESS HEATING VACCUM, LP SECTION, TRACING, JACKET.
MS AND LS INTERCONNECTION

59. STEAM AND CONDENSATE (WASHING) NETWORKS
CONDENSATE NETWORK
1. KW CONDENSATE (180 KG/CM2)
P11
2. HW CONDENSATE (35 KG/CM2)
P10
3. LW CONDENSATE (10 KG/CM2)
P13.
HW AND LW INTERCONNECTION

61. WHAT IS SIGNIFICANCE OF DELTA T IN REACTOR?
WHY HP PRESSURE HIGH (R1 BOTTOM = 160 KG/CM2)?
WHY MP PRESSURE 16 KG/CM2 ?
WHY LP PRESSURE 4 KG/CM2 ?
WHY VACCUM SECTION REQUIRED ?
WHAT IS DIFFERENCE BETWEEN STRIPPING AND DECOMPOSITION ?

62. IMPROVEMENT IN MATERIAL SELECTION
Srno. E8quipment Till 1982 2004 onwards
1 REACTOR AISI316L M 2RE 69 25/22/2
2 CARBAMATE CONDENSOR AISI316L M 2RE 69 25/22/2
3 STRIPPER TITANIUM BIMETALLIC
4 CARBAMATE EJECTOR AISI316L M HVD 1
5 MP DECOMPOSER AISI316 AISI316L
6 LP DEOMPOSER AISI304L AISI316L
7 NH3 CONDENSOR KILLED CS AISI316L
8 MP ABSORBER KILLED CS AISI304L

63. PRILLING BUCKETS
LATEST AVAILABLE BUCKETS ARE MADE OF TITANIUM (SIIRTEC
NIGI , ITALY), ALUMINIUM OR STAINLESS STEEL.
Snam suggest titanium because it is more resistant than aluminium to
wear caused by the high jet velocity of urea melt through the holes,
which cause a non uniform increase of size of holes, gradually
affecting the grain size distribution of urea prills.
Titanium buckets lasts longer than aluminum
Being about lighter than SS bucket, titanium bkt is easier to handle,
virtually have same operating life as SS.
Titanium is costly than other options.
Titanium buckets provide high uniformity in prill grain size, reduce
fines, generation, low dust, low prill ‘s temperature, guaranteed
performance.

64. OTHER DEVELOPMENTS
Installation of Flare unit to burn off the vented gas to protect
environment
Early carbamate injection as soon as feed is introduced into
Urea reactor, this helps in absorption of carbamate gas, thus
provide better control inside the reactor.
Direct savings in power and steam consumption due to
modification in timings of steaming and ammoniation
through startup line.

66. STAMICARBON UREA HISTORY
DSM/Chemiebouw (Chemiebouw was Stamicarbon’s predecessor) started
to develop its own urea process based on montecatini’s urea process in
1945 and started licensing urea technology to its parents company DSM in
Gellen in 1954.
DSM, with Stamicarbon’s assistance has since increased the original plant
capacity of 150mtpd to 2300 mtpd single line.
Basic technology changes took place when pipe reactors were replaced by
autoclaves, and when the CO2 stripping process was introduced.
DSM is the first to benefit the latest technological breakthrough , the
POOL REACTOR.

68. Stamicarbon Process (CO2 stripping process)

69. Stamicarbon Recent Innovations
Urea 2000 plus technology
Safurex SS material of construction
Urea granulation Technology
AVANCORE Urea process

70. Urea 2000 plus technology
Application of pool condensation in the synthesis
section
Combined condensation and urea formation in one
vessel
Reduction of plant height
Reduction of investment cost
Simplified operation

71. Urea 2000 plus technology
Available in two variants
1. Pool reactor plant
2. Pool condenser plant

72. 1. Pool Reactor plant

73. 2. Pool Condenser plant

74. Safurex Duplex SS
Developed together with Sandwik
Better mechanical strength as compared to fully austenitic stainless
steels
Zero oxygen required for passivation so intrinsically safe plant
Lower corrosion rates, less maintenance cost
No SSC, no crevice corrosion
Improved weld ability. Higher strength, reduction of piping cist
Less NH3 loss

75. AVANCORE Urea process

76. AVANCORE Urea process

77. INCLUDES ALL ADVANTAGES OF UREA200PLUS
NO HP SCRUBBER
LOW LEVEL ARRANGEMENT, YET STILL ALL GRAVITY
FLOW
USE OF SAFUREX , AIR, AS LOW AS 0.1 vol% of O2
LOW INVESTMENT
LOW MAINTENANCE COST
FUTURE OF STAMICAARBON
AVANCORE Urea process

78. History of Stamicarbon

79. Flaring : Stamicarbons view
Venting of NH3 containing off gases is preferred option for all
emissions
Flaring of NH3 containing off gases is not safety consideration
Flaring of NH3 containing off gases can not be justified from
environmental point of view
Flaring of discontinuous emissions can be used to minimize
nuisance to urea plant neighbors
But still Stamicarbon has full flaring design
available

81. N/C Ratio Meter
N/C meter has been added for improved control of the molar
ratio outlet reactor. The principle of this N/C meter is based on
the linear relationship between liquid density and N/C ratio.
By installing this meter, accurate and continues reading of N/C
ratio is secured so that the process can be operated at an
optimum ration to achieve highest reactor efficiency. Plant
operators using this N/C ratio meter claim a far more reliable
plant performance, resulting in considerable savings.

83. TOYO ENGINEERING CORPORATION (TEC)
TOYO ENGINEERING CORPORATION (TEC), one of the major Urea technology
licensor, established in the late 1970.
Processes established by TEC are;
1.TOTAL RECYCLE “B”
2. TOTAL RECYCLE “C”
3. TOTAL RECYCLE “C1”
4. TOTAL RECYCLE “D”
5. ACES
6. IMPROVED ACES (ACES -21)
The improved ACES 21 technology offers low investment cost as it reduces
number of equipments in urea synthesis loop with the urea reactor installed on
the ground with CO2 stripping process. Further, reduction in energy consumption
has been achieved through optimization of operating conditions at lower
pressure than earlier processes.

84. ACES Process
The main concept of the original ACES Process is to minimize energy input to the urea plant by
combining the features of solution recycle process and stripping process i.e. a high CO2
conversion and the highly efficient separation of unreacted materials.

The ACES Process drastically reduced steam consumption compared to Total Recycle
Process.
The ACES Process, by ensuring NH3 to CO2 molar ratio (N/C ratio) of 4.0 and an operating
temperature of 190 °C in the reactor give CO2 conversion of 68%, the highest among modern
urea processes.
The high CO2 conversion reduces the energy required for decomposition of unconverted
materials.
The proprietarily designed tray-falling film Stripper efficiently decomposes and separates
ammonium carbamate and excess ammonia in urea synthesis solution from the reactor.

86. Heat Integration scheme

87. THE IMPROVED ACES (ACES 21) PROCESS
ACES was improved, aiming at installing the reactor on the
ground level, maintaining advantages of ACES concepts based
on proven CO2 stripping technology.
The two stage synthesis concept of combination of VERTICAL
SUBMERGED CARBAMATE CONDENSER (VSCC) and the
reactor is employed to enable the reactor to be installed on
ground level and to simplify the synthesis loop.

90. Highlights of ACES Process
A vertical submerged carbamate condenser, functioning as carbamate condenser,
HP scrubber and the primary urea reactor
A vertical reactor to complete reaction from carbamate to urea, as the secondary
reactor
A vertical falling film type stripper to decompose and separate unreacted
carbamate and excess ammonia by CO2 stripping.
A HP ejector motivated by HP liquid ammonia to supply driving force for the HP
loop circulation, so that the reactor is installed on the ground level and other HP
vessels are laidout horizontally, as well as to increase N/C ratio in the reactor high
enough so as to achieve the high CO2 conversion.

91. Advantages of ACES process
1. The horizontal layout of HP vessels has the following advantages compared to
the vertical layout.
(a) less HP piping and construction materials are used;
(b) easier erection using commonly available construction equipment and
techniques;
(c) easier operation and maintenance
2. Combining the functions for carbamateformation, heat recovery, urea
synthesis, and inert gas scrubbing into one vertical submerged carbamate
condenser has the following advantages in comparison with conventional
separate reactor and falling film carbamatecondenser:
(a) fewer and smaller sized HP vessels;
(b) a smaller heat transfer area for heat recovery;
(c) less HP piping and construction material are required

92. Advantages of ACES process
3. Simplified synthesis loop offers the followings advantages over conventional
stripping technologies:
(a) less HP piping and construction materials are required;
(b) easier operation and maintenance
4. Improved design for the reactor and the stripper give the following advantages
in comparison to conventional ones:
(a) less volume and weight for both the reactor and the stripper;
(b) easier reactor and stripper fabrication
5. Optimizing N/C ratios at different levels for the carbamatecondenser and the
reactor at lower synthesis pressure results in the following advantages over the
ACES Process:
(a) lower mechanical design pressure of HP vessels and rotating equipment;
(b) less energy consumption

95. CASALE GROUP FOR UREA
Operating from Swirzerlandsince 1920, the casalegroup was a pioneer in ammonia synthesis, but
subsequently branched out into methanol, urea and now related technology such as hydrogen and DME.
HIGH EFFICIENCY REACTOR TRAYS : these from the basis of Casale’surea revamp technologies, with the
trays alone, together with hydrogen peroxide passivationsystem, capacity increases of the order of 15-20%
ad in some cases as much as 30% can be achieved.
VAPOR RECYCLE SYSTEM: the vapor recycle system, in combination with high efficiency trays can give
large capacity increases in the synthesis section, of the order of 50%, in any conventional stripping plant.
HIGH EFFICIENCY COMBINED PROCESS : It is the counterpart for total recycle plants, and is also based
around the high efficiency trays. Again debottlenecking capacity increases of 50% or more are possible.
FULL CONDENSER AND SPLIT FLOW CONCEPTS : these are modifications loop in CO2 stripping plants
and again can gain large capacity increases in the synthesis section.
HIGH EFFICIENCY HYDROLYSER AND UREA RECOVERY SYSTEM : this can reduce emissions from
urea plant.
CASALE CHEMICALS: as well as technology for producing H2 by water electrolysis, casalealso offers a
range of technologies for production of chemicals downstream from methanol plant, including
formaldehyde, DME and now, methanol to olefins.

96. NEW REACTOR TRAY DESIGN
The principle of high efficiency trays;
1. Mass transfer factor
2. Contact pattern of phase
3. Fluid dynamics factors
4. Interfacial surface area
5. Geometry of reactor vessel
6. Chemical kinetics factor
7. Temperature and pressure
The new generation trays (HET) already launched in urea plant claim to be more effcient
w,r,t, conversion, energy saving.
Snam plants like GNFC, Nagarjuna, Indogulf fertilizers and NFL Nangal have
installed HET in urea reactors. HET are different from bottom to top of the reactor. The
number of holes in bottom trays are more compared to top.

98. DIFFERENCE BETWEEN
CONVENTIONAL AND STRIPPING PROCESS
CONVENTIONAL
DEFINATION –the process based on the 1
st
principle of decrease in pressure and increase
in temp and then have a series of
decomposition stage where the reactor
discharge is treated in successively at lower
pressure
Pressure of Reactor->200 ata
UTI –210ATA
MTC -250ATA
CP1 -380-400 ATA
MONTEDISON –210 ATA
Conversion -High
Water carryover -high above 10% because of
high differential pressure
Energy –high due to high pressure and water
recycling
Future –due to high energy and high cost of
liner , no future
STRIPPING
DEFINATION –To reduce the partial pressure of
product by swamping the system by one of the reactant
which reduce the partial pressure of the other reactant
considerably, without changing the total pressure.
Either CO2 or NH3 or both can be used as stripping
agent
Pressure of Reactor-< 200 ata
STAMICARBON –140ATA
ACES -155 ATA
SNAMPROGETTI -158 ATA
Conversion -low
Water carryover -Low about 3-4% because stripping at
same pressure of reactor differential pressure
Energy –low due to low pressure and less recycling of
water
Future –Good because of low cost

99. CASALE’s HET
These high efficiency reactor trays are equipped with liquid risers
where the liquid enters the following compartment. By staggering
the liquid risers, the liquid is forced to the torus circulation and
channeling is eliminated. To avoid back mixing, the gas cushions
were increased and this make the trays less sensitive to horizontal
variations of the tray.
CASALE HETs drastically increase the efficiency of the reactor (upto
4-5 %) debottlenecking the HP synthesis section allowing to achieve
capacity increases up to 30-35 % .

100. CASALE’s HETs

101. CASALE HEC PROCESS
The HEC process, use for the revamping of
conventional total recycle plants, combines a very
efficient “once through” synthesis section with the
conventional reactor obtaining an average conversion
of 72% (at increased capacity).
Due to this conversion increase, a large capacity
increase can be obtained with minimum amount of
additional equipment and minimum shutdown.

102. CASALE HEC
PROCESS

103. CASALE VAPOR RECYCLE SYSTEM (VRS)
The VRS, used for the revamping of stripping plants,
eliminates the water from the recycle carbamate before
sending it to the synthesis section obtaining conversions up to
67-68% (at increased capacity).
Due to this conversion increase, a large capacity increase can
be obtained with minimum amount of additional equipment
and minimum shutdown.

104. CASALE VAPOR RECYCLE SYSTEM

105. SIPHON JET PUMPS TRAY
Although the high efficiency trays ‘improved the reactor efficiently
significantly, they did not improve the mixing rate.
In practice, it appeared o be difficult to keep the strict tolerances for
the gap between the reactor tray and reactor wall because of the no
roundness of the reactor. To improve the mixing rate in the reactor
compartments and to avoid strict mechanical tolerances,
STAMICARBON recently developed a anew generation of HET known
as Siphon jet pump trays.
These trays increase mixing efficiency in the reactor compartment,
thereby reducing dead zones and hence maximizing the effective
reaction volume. The increased reactor performance allows the
production rate to be increased and/or lowers overall steam
consumption.

107. SIPHON JET PUMP TRAYS
The compartments, separated by sieve trays, are equipped with draft
tube. Inside the draft tube there is a two phase flow with the density
of this two phase flow being considerably less than the liquid
density t the out side of the draft tube.
By this density difference liquid circulation is enhanced further
stimulating the mixing and the negative effects of back mixing and
channeling are avoided.
The gas holes in the tray are more centered than in the conventional
tray design to improve the driving fore and the tray is equipped with
a ring that acts as a venturi to improve the mixing rate.

108. COMPARISON OF TRAYS
CONVERSION
C
A
B

109. NH
3 LIQ CO
2 GAS
R1 OVERFLOW LINE
15 SIEVE TRAYS
STATIC MIXER
(VORTEX FORMATION)
LONGITUDINAL SECTIONING
ELEMENTS
TO STRIPPER
NIIK PROPOSAL TO IMPROVE R1
EFFICIENCY