3. • The hydrogenated natural gas is fed
to the sulphur absorbers.
• Zinc oxide catalyst is in the form of
4 mm cylindrical extrudes.
• Operating temperature is approx.
ZnO + H₂S ↔ ZnS + H₂O
ZnO + COS ↔ ZnS + CO₂
• Sulphur content in the natural gas is
less than 0.1 ppm by weight.
4. • Desulphurized gas is converted into
synthesis gas by catalytic reforming
of the hydrocarbon mixture with
steam and the addition of air.
CnH2n+2 + 2H₂O ↔ Cn-1H2n + CO₂ + 3H₂ - heat
CH4 + 2H₂O ↔ CO₂ + 4H₂ - heat
CO₂ + H₂ ↔ CO + H₂O – heat
• Reactions take place in two steps.
1. Primary reforming
2. Secondary reforming
5. • Exothermic reaction which occurs in
this section is:
CO + H2O ↔ H2 + CO2 + heat
• Shift reaction takes place in the two
1. HT CO-Converter.
2. LT CO- converter with process
gas cooling after each converter.
6. • Outlet gas from CO converter
contain 18.32 mole% CO2
• The solvent used for CO2
absorption is aMDEA(40%)
• Consists of a two stage CO2
absorber, a CO2 stripper and two
R3N + CO2 + H2O ↔ R3NH+ + HCO3
2R2NH + CO2 ↔ R2NH2
+ + R2N-COO-
7. 1. Main trip (local) any major abnormality will observe immediately it will trip the plant.
2. Inlet feed trip which maintain the feed quantity at 10,000kg N.G and 30,000 stream.
3. Flue gas fan (logic: 2 out of 2) where two switch is provided for the control rpm of the I.D fan
and F.D fan. Tripping will only if both switches gets tripped. I.D fan maintained at 525 rpm
and F.D fan at 400 rpm.
4. Outlet temperature of reformer. (logic 2 out of 3) Here 3 number of switches is provided for
the tripping of reformer. It maintain the temperature of the reformer at 880OC (max). It 2
switches get trip of 3 switches tripping will occurs.
5. REF box pressure (logic 2 out of 3). The inside pressure of the reformer box is maintain to at
its maximum value of -50 mmWC and lowest at the 0 mmWC. currently maintained at -14
6. S/C (stream to carbon ratio) as per the process effectiveness the S/C is maintained to
approx. 2.1KG/KG. if any how the ratio get disturb the tripping occurs
7. High pressure stream drum. The level tripping is placed over the drum for the maintenance
of the D.M water level which is at 33%.
8. Medium pressure stream drum leveled at 23%.
9. I.S.R drum level trip switch which level maintained at 20% DM water.
8. System Actual value Trip value
Reformer outlet process gas temp 8250
C (2 of 3)
Reformer box pressure for ID-FD -15 mmWC 0 mmWC (max) &
-150 mmWC (min)
HP system drum level 75 % 33 % (2 of 3)
MP system drum level 75 % 20 % (2 of 3)
S/c ratio 3.05 2.1
Boiler free water circulation flow 265 m3
/ hr 80 m3
9. Process safety -
1. Safety valves : Safety relief valves
2. For pressured lines –
( i ) Primary : (a) Pressure relief valve
(b) Rupture disc
(c) Stand pipe
3. Hydrocarbon & Chlorine gas detector is placed all over the plant
4. Fire related safety –
I. Smoke detector is placed all over the control room, electric substations & instrument
II. MCP (manual call point) is place at critical place for the certain emergency conditions.
III. Fire extinguisher are placed (dry chemical powder & CO2 cylinders)
IV. Header down stream
Wet risers & dry risers
( ii ) Secondary : (a) Check valve
(b) Restriction orifice
(c) Control valve
10. 1. Respiratory –
• Skin Protection :- sunburn cream, long sleeved clothes, PVC suit
• Inhalation/Ingestion :- canister gasmask, chemical cartridge
dust mask, BA set
2. Non-Respiratory –
• Head Protection :- helmets, caps
• Eye Protection :- spectacles/goggles, shields, visors
• Hand Protection :- gloves and barrier creams
• Ear Protection :- ear muffs and plugs
• Working at Height :- harness and safety belt, safety net
• Foot Protection :- safety shoes/boots
12. 1.Property damage incident (fire/explosion)
DATE – 01/01/2018
PLACE – Control room opposite side garden area
CAUSE – minor synthesis gas leakage from underground synthesis header, indentified due to
minor fire of grinding spark.
ACTION – part of leaky header will be carried out.
2. Equipment damage incident due to toxic release
DATE – 20/06/2018
PLACE – E0506 inlet flange joint leakage
CAUSE – As such there are no chances to leakage might be due to start up after long shut down
ACTION – Ammonia synthesis loop pressure decrease to reduce the leakage.
14. NO. NAME UNIT ACTUAL VALUE
1 AMMONIA PRODUCTION MTPD 1370
1 NG,FEED+FUEL SM3
2 MPS IMPORT MT/MT 0
3 MPS+LPS EXPORT MT/MT -1.35
4 POWER IMPORT KWH 377.953
5 DM WATER M3
6 RAW WATER M3
1 NG Rs/SM3 34.637
2 STEAM IMPORT Rs/MT 0
3 STEAM EXPORT(MP+LP) Rs/MT -1942.79
4 POWER Rs/KWH 4.21
5 DM WATER RS/M3 99.93
6 RAW WATER RS/M3 29.46
TOTAL OPERATING COST RS/MT 29179.08448
15. Hazard and Operability Study (HAZOP)
• SYSTEM is the subject of a risk assessment and generally includes a process, product, activity,
facility or logical system
• Hazard and Operability Analysis (HAZOP) is a structured and systematic technique for system
examination and risk management.
• In particular, HAZOP is often used as a technique for identifying potential hazards in a system
and identifying operability problems likely to lead to nonconforming products.
• HAZOP is based on a theory that assumes risk events are caused by deviations from design or
16. Man power No. of shift Extra Total number of
2 3 1 7
DCS 3 3 2 11
4 3 1 13
4 3 2 14
Lab 2 3 1 7
workman 3 3 2 11