Production of Prilled Urea through Prilling Methode

Prilled urea is produced through a process called prilling, which involves the following steps:

1. Ammonia and carbon dioxide are reacted under high pressure to form ammonium carbamate.

2. The ammonium carbamate is then dehydrated to form urea, which is in a molten state.

3. The molten urea is then allowed to flow through a prilling tower, where it is sprayed into droplets.

4. As the droplets fall through the prilling tower, they solidify into small spherical pellets called prills.

5. The prills are then cooled and screened to remove any fines or oversized particles.

6. The final prilled urea product is then stored and packaged for distribution and use as a nitrogen fertilizer in agriculture.

Overall, the production of prilled urea involves precise control of temperature, pressure, and flow rates to ensure the formation of high-quality prills with the desired physical and chemical properties.

1. Sule Alabi
Jonathan Arana
Elizabeth Moscoso
Oleg Yazvin
Mentor: Dan Rusinak –Middough
Production of
Prilled Urea

2. Clean Water
from CHP Plant
Prilled Urea (99.3%)
Product
BFD of Urea & Prill Plant
"Dirty Water"
Rich in NH3, CO2 & Impurities
Cleaned Air Out
Urea Solution
(72%)
Condensate Water
Solid Urea (99.3%)
Output NH3 Purge & Urea Solution
To Amm. Nitrate & UAN Plants
Urea
Production
Plant
Waste Water
Treatment
Plant
Evaporator
Unit
Inlet NH3 & CO2
from NH3 Plant
CO2 & NH3 Recycled Gas
Air In
Prilling
Tower

3. Urea Production Plant PFD
1
2
3
4
5
6
78 9
10
11
12
13
14
DECOMPOSER
water
Urea (72%)Solution
Un-reacted Gases

4. Urea Production Plant Calculations
Some Assumptions:
Stream 1 2 3 4 5
NH3 Feed Gas Exit from Stripper Solution from Scrub Solution from Pool Gas Recycle to Scrub
Ton Moles Tons Ton Moles Tons Ton Moles Tons Ton Moles Tons Ton Moles Tons
Totals 77.31 1314.33 77.59 2441.84 140.00 3565.00 151.47 4430.96 10.50 234.30
Compounds
CO2 41.59 1829.84 10 440.00 18.57 817.14 2.06 90.79
NH3 77.31 1314.33 36.00 612.00 100 1700.00 75.97 1291.52 8.44 143.50
AC 15 1155.00 10.98 845.16
Urea 15.48 928.57
Water 15 270.00 30.48 548.57
Properties
Temperature 185
o
C 185
o
C 185
o
C 185
o
C 60
o
C
Pressure 140 Bar 140 Bar 140 Bar 140 Bar 1 Bar
Calculations:
Input Variables
CO2 input (tons) 1153.15
NH3 / CO2 Input Mole Ratio 2.95
Input CO2 Split into Reactor 0.90
Reactor
Extent of Reaction 1 Based on CO2 0.60
Extent of Reaction 2 Based on CO2 0.50
Fraction of CO2 that gets converted 1.00

5. Compound Mass Flow
Rate IN
(TPD)
Mass Flow
Rate OUT
(TPD)
Mole Flow
Rate IN (ton
mole/day)
Mole Flow
Rate OUT
(ton
mole/day)
AC 506.7 12.5 6.5 0.13
Urea 1513.8 1893.5 25.2 31.6
Water 99.54 214.2 5.53 11.9
NH3 2.21 2.21 0.13 0.13
CO2 5.72 5.72 0.13 0.13
TOTAL 2128 2128 37.53 43.9
Q = 177 BTU/ton
Material & Energy Balance for Decomposer Unit
Basis:
1893 TPD of Urea produced
Composition of Urea 72%

6. Waste Water Treatment Plant PFD
13
31
32
33

7. Waste Water Treatment Plant Calculations
Assumptions:
Basis of 50,000kg of
effluent sewer water
10 NH3 ppm specification
from EPA
Assumed same PPM for
CO2
Inlet Water composition
from existing Indian Urea
Plant
1% of recycle is vented to
air
Calculations:
Stream 13 31 32 33
Total 532,066.00 477,245.34 50,000.00 4,820.66
Mass (kg) Balance
Components
CO2 38,084.00 37,703.11 0.05 380.84
NH3 45,332.00 44,878.63 0.05 453.32
Urea 4,985.00 4,935.15 0.00 49.85
Water 443,665.00 389,728.45 49,999.90 3,936.65
Mole (kmol) Balance
Component
CO2 865.55 865.54 0.00 216.39
NH3 2,666.59 2,666.59 0.00 666.65
Urea 83.08 83.08 0.00 20.77
Water 24,648.06 21,870.28 2,777.77 5,467.57
Total 28,263.27 25,485.50 2,777.78 6,371.37
Properties
Temperature 25
o
C 25
o
C 25
o
C 25
o
C
Pressure 1 bar 1 bar 1 bar 1 bar

8. Evaporator Unit PFD
15
16
26
25
24 17
23
21
22
18
19
20
27
Condenser
Eductor
Evap1
Evap2
Storage Tank
Product Urea (99.8%)
H.P. Steam
Urea Solution
(72%)
Streams 21, 26, 19:
To Waste Water Treatment

9. Evaporator Unit Calculations
Assumptions:
Input Urea 1572.48Tons
Input Water 611.52Tons
wt% Water Evaporated 1 95%
wt% Water Evaporated 2 85%
wt% Water Condenses 65%
Input Steam 3Tons
Calculations:
Stream # 15 16 17 18 19
Urea (72%) to Tank Urea 72% Solution Water from Evap 1 Urea from Evap1 Steam from Evap 2
Ton Moles Tons Ton Moles Tons Ton Moles Tons Ton Moles Tons Ton Moles Tons
Totals 60.18 2184.00 60.18 2184.00 32.27 580.94 27.91 1603.06 32.27 580.94
Compounds
Urea 26.21 1572.48 26.21 1572.48 26.21 1572.48
Water 33.97 611.52 33.97 611.52 32.27 580.94 1.70 30.58 32.27 580.94
H.P. Steam
Properties
Temperature 80
o
C 80
o
C 110
o
C 95
o
C 80
o
C
Pressure 5 Bar 5 Bar 0.8 Bar 0.8 Bar 1 Bar

10. Cyclone
Screen
Bag House
Pump
Melting Furnace
Dehumidifier
Prilled Urea (99.8%)
Urea Melt (99.8%)
Prilling
Tower
27
30
29
Air from Atm
Cleaned Air
28
Prilling Tower PFD

11. Prilling Tower Calculations
Assumptions:
Mass flow rate of Prilled
Urea is 738.22 TPD
According to the EPA the
allowed urea dust is 3.8
lb/ton of Prilled Urea. For
ammonia dust the
allowed emission is 0.87
lb/ton of Prilled Urea.
Stream 27 28 29 30
Urea Melt
(99.8%)
Air From
Atm
Prilled Urea
(99.8%) Cleaned Air
Tons Tons Tons Tons
Totals 739.94 500 738.22 501.724
Component
Urea Melt 739.94 --- --- ---
Ammonia Dust --- --- --- 0.32
Urea Dust --- --- --- 1.40
Prilled Urea --- --- 738.22 ---
Air --- 500 --- 500
Properties
Temperature 185
o
C 25
o
C 25
o
C 25
o
C
Pressure 1 bar 1 bar 1 bar 1 bar
Calculations:

12. Estimated Economics
Materials Cost (Money We Spend) Amount Overall Cost
NH3 $521.00Per Ton 891.07Tons Per Day $464,247.47Per Day
CO2 $15.00Per Ton 1153Tons Per Day $17,295Per Day
Product Price (Money We Get) Overall Price
Urea to UAN $230.00Per Ton 694.48Tons Per Day $159,730.40Per Day
Prilled $570.50Per Ton 739.7Tons Per Day $421,998.85Per Day
Profit: $100,186.78Per Day
Profit: $36,568,174.70Per Year

13. Estimated Total Cost
2009-Q’atar built a 3,836 TPD Urea Plant
Plant Cost: $610 Million Dollars.
Urea Plant Produces 1,384 TPD
Using 6/10ths rule and 2010 Cost Index
Plant Cost: $389.4 Million Dollars.
About 10 years to break even

14. Questions?