National Fertilizers Limited operates five urea plants in India with a total annual capacity of 35.68 lakh metric tons. One of its plants is located in Nangal, Punjab and has an installed capacity of 478,500 metric tons per annum. The Nangal plant produces urea using a Montedison total recycle process and consists of steam generation, ammonia production, urea synthesis, and nitric acid generation facilities. Urea is produced through a reaction of ammonia and carbon dioxide that yields ammonium carbamate as an intermediate and urea as the final product. The urea melt is then prilled into spherical granules and packaged meeting quality specifications.

1. NATIONAL FERTILIZERS
LIMITED , NANGAL

2. NFL
 NFL has five gas based Urea plants viz Nangal & Bathinda in Punjab, Panipat in
Haryana and two plants at Vijaipur in District Guna, Madhya Pradesh
 The company has a total annual installed capacity of 35.68 LMT and is the 2nd
largest producer of Urea in the country with a share of about 16% of total Urea
production in the country

3. FEATURES OF NANGAL UNIT
 Installed Capacity: 478500 MTPA
 Capital Investment: 229.19 Crores
 Commencement of Production: November 1, 1978
 Commercial production after revamping started on Feb 1st,2001.

4. NFL Nangal plant
 NFL Nangal plant can be divided into 4 parts-
1.Steam Generation Plant
2.Ammonia Production Plant
3.Urea synthesis Plant
4.Nitric Acid Generation Plant

5. UREA PROCESS
 BRIEF DESCRIPTION :
 It is a Montedison total recycle process.
 Before revamping its capacity was 1000 T/day
 But today its capacity is 1650 TPD
 Ammonia: KBR SMR(Steam Methane Reforming) with Purifier Technology
 Urea: Technimont Total Recycle Process
 Raw material: Coal , LNG/ RLNG, Power, Water

6. UREA PRODUCTION
 CO2 Compressor & H.P.Pumps
 Urea synthesis.
 Urea separation.
 Recovery section.
 Vacuum section.
 Prilling section.
 Waste water section.

7. Specific Consumption
 Ammonia 0.574 T/T of urea
 Carbon dioxide 0.745 T/T of urea
 Steam 30ata 1.23 T/T of urea
 Power 135 kwh

8. Reactor feed
 The expected best operating condition are:
New sec. Old sec.
Capacity (TPD) 600 1050
 Pr (ata) 220 220
 Temp (ºc) 196 196
 N/C 2.9 2.75
 H/C 0 0.7
 Conversion (%) 69 55
0
200
400
600
800
1000
1200
Chart Title
new section old section Column1

9. Reactions
 The principal raw materials required for this purpose are NH3 &
CO2 .Two reactions are involved in the manufacture of urea.
First, ammonium carbamate is formed under pressure by
reaction between CO2 & NH3.

 CO2 + 2NH3 <-→ NH2COONH4 ∆H= -37.4 Kcal

 This highly exothermic reaction is followed by an endothermic
decomposition of the ammonium carbamate.

 NH2COONH4 ↔ NH2CONH2 + H2O ∆H= + 6.3 Kcal

11. Feed:-
 Ammonia : 20C and 20-30 ata
 Demethanolated CO2 : 40C and 11 ata
sulfer content <1mg/m3

12. Urea Separation
 1st stage
Pressure 70 Kg/cm2
Temperature 185 C
Urea conc. 54.5%
 2nd stage
Pressure 12 Kg/cm2
Temperature 150 C
Urea conc. 65%
 3rd stage
Pressure 3 Kg/cm2
Temperature 130 C
Urea conc. 72%

13. Vacuum Section
 1st stage vacuum system
Pressure 0.75 ata
Temperature 128 C
Urea conc. 95%
 2nd stage vacuum system
Pressure 0.35 ata
Temperature 138 C
Urea conc. 99.6%

14. Prilling section
 The 99.5% urea melt having a temp of 140 C from 2nd stage
saparator is then pumped and fed to spray nozzles of the prilling
tower
 Therer are 4 sprayer boxes each having 16 sprayers.
 It is natural draft rectangular prilling tower
 height 75 meters
 free fall height 53 meters
 Urea dust loss 84 kg/Hr
 scrapper type conical
 Air flow 8,00,000 Nm3/h

15. Product Quality
 Total Nitrogen 46.5%
 Moisture 0.35%
 Biuret 0.8-0.9%
 Mean prill dia 1.75mm
 Sieve analysis
Over size nil
Proper size 98.5%
Under size 1.5%

16. Specification of Urea being
produced at Nangal
 Total Nitrogen 46.5%
 Moisture 0.5%
 Biuret 0.8-0.9%
 Mean prill dia 1.75mm
 Sieve analysis
Over size nil
Proper size 98.5%
Under size 1.5%

17. Disadvantages
 When applied to a bare soil surface, urea hydrolyzes rapidly result
into loss of significant quantity of ammonia by volatilization. Such
losses vary from soil to soil and are greater for urea in a pellet form
rather than in solution form.
 It is phytotoxic due to rapid hydrolysis of urea in soils can cause injury
to the seedlings by ammonia,
 The fertilizer grade urea may contain toxic biuret which is formed
during urea manufacture by an excessive temperature rise. Above
2% concentration of biuret in urea is harmful to plant

18. Conclusion
 For the development and upgradation of urea technology. Indian industry
depends on the already established international process licensors and design and
companies. There is hardly any R & D effort towards development of process
technologies for urea except for development of modified total recycle process by
PDIL which has been utilised in Namrup-III plant.
 R&D unit should be set up to deal with the development of fertilizer technologies.

19. Thank You!!!