1. Ammonia (NH₃)
Basic raw material for urea production. Produced from natural gas in the ammonia plant section.
2. Carbon Dioxide (CO₂)
Second main feedstock. Comes as a by-product from ammonia production and reacts with ammonia to form urea.
3. Urea Synthesis Reactor
High-pressure vessel where ammonia and CO₂ react to form ammonium carbamate and urea.
4. Ammonium Carbamate
Intermediate compound formed first in the reactor before converting into urea.
5. HP (High Pressure) Section
Part of plant operating at very high pressure (140–200 bar). Includes reactor, stripper, and condenser.
6. MP (Medium Pressure) Section
Used for decomposing unreacted carbamate and recovering ammonia/CO₂.
7. LP (Low Pressure) Section
Final recovery stage where remaining gases are separated and recycled.
8. Stripper
Equipment that removes unreacted ammonia and CO₂ from urea solution.
9. Carbamate Condenser
Converts gaseous ammonia and CO₂ back into liquid ammonium carbamate.
10. Reactor Outlet
Stream leaving reactor containing urea + unreacted chemicals.
11. Urea Solution
Mixture of urea and water before concentration and finishing.
12. Evaporator
Removes water from urea solution to increase concentration.
13. Prilling Tower
Tall structure where molten urea is sprayed and solidified into prills (granules).
14. Granulator
Alternative to prilling tower; produces uniform-sized urea granules.
15. Recycling Loop
System that recovers unreacted ammonia and CO₂ and sends them back to reactor.
16. Vacuum System
Used to lower boiling point during evaporation for energy saving.
17. HP Pump
High-pressure pump used to feed liquid streams into reactor system.
18. Steam Jacket
Heating system used to maintain temperature in equipment.
19. Corrosion Inhibitor
Chemical added to reduce equipment corrosion due to carbamate.
20. Process Condensate
Water separated from urea process, usually treated before reuse.
21. Synthesis Loop
Closed loop system of reactor, stripper, condenser, and recycle units.
22. Pressure Letdown Valve
Reduces pressure between HP, MP, and LP sections.
23. Ammonia Recovery Section
Area where unused ammonia is recovered and reused.
24. Urea Formaldehyde
Additive sometimes used to improve fertilizer quality and handling.
25. Biuret
Side product formed at high temperature; too much is harmful for plants.
⚙️ Bonus Interview Terms (Very Important)
- Turnaround (TA) – Planned plant shutdown for maintenance
- PFD (Process Flow Diagram) – Full process flow layout
- P&ID (Piping & Instrumentation Diagram) – Detailed engineering diagram
- Mass Balance – Calculation of input vs output material
- Heat Exchanger – Equipment for heat transfer
- Load Fluctuation – Change in production rate
Leave a comment