8. Cost of imported sulphur of India
in recent years
YEAR QUANTITY (million tonne ) COST in Rupees ( crore )
2008 0.8 300
2009 1 340
2010 1.2 370
2011 1.4 390
2012 1.75 450
2013 2 500
9. DIFFERENT TECHNIQUE USED TO
OBTAIN SULPHUR
1.From H2S ( Claus Process )
2.Earth surface
3. Frasch process
10. PRESENT TECHNOLOGY AND DETAILS
1. Claus Process : MCRC 99 % recovery
2. Section :Thermal section and Catalytic section
3. Raw Materials : a. H2S , b. O2
REACTION :
1] H2S + 3/2 O2 SO2 + H2O
2] 2H2S + SO2 nSx + 2H2O
11. Different technologies used by oil
refineries for recovery of sulphur
Technologies H2S %
required
Recovery Advantages Disadvantages Bed Type
Straight type 80 -90 % 99% High recovery more bed
required
3
Split type 15 -50 % 93 % Burner on
continuously
Less recovery 2
Oxygen
enrichment
80 -90 % 98-99% Less S02
emission
Pure O2 required 2-3
Acid gas
enrichment
70- 85 % 95-96 % 1. Solvent
increases
recovery
2. Undesirable
reactions
2
12. CO
C-2
C-3
ENDS : 1. F : Furnace
2. WHB : Waste heat boiler
3. LB : Line burner
4. C -1 : Condenser no 1
5. CO : Converter
6. C- 2 : Condenser no 2
7. C- 3 : Condenser no 3 Present Recovery : 85 %
13. Capital cost of plant based on
capacities
Capacity ( Mt/ day) Cost in Rs ( Crore )
40 300
70 600
100 800
140 1000
14. Operating cost of plant
Type Plant capacity
70 mt/day
Utilities 5 Cr/year
Catalysts and chemicals 2 Lakh/year
Operations and
maintenance
2 Cr/year
Total 7.2 Cr/ year
16. Design parameters :
1.Process gas : H2S , S8 , S4 GAS ( SHELL SIDE )
2.Tube Side : Boiler feed water
3.U :55 W/m2 K
4.LMTD :63.84 C
5.Load [Q]: 97399.27 W
6.Heat transfer area : 5.423 m2
7.Temperature [Inlet] : 260 C
8. Working Temperature[Outlet] : 160 C
9.Design Temperature [Inlet] :315 C
10.Design Temperature[Outlet] :190 C
17. Target areas•
The different parameter were studied and following points were
put forward to increase efficiency , reduce the manufacturing
and operating cost of condenser :
2. Applying an converter inside tube side of sulphur condenser.
3.Converting S4, S6 sulphur molecules to S8 (desired product)
which will decrease the operating cost of condenser .
4.Using alternative options for material of Construction ( MOC )
which will increase overall heat transfer coefficient (U) and will
lead to increase in production of sulphur .
5.Reducing the residence time of recovering sulphur by changing
the temperature and pressure parameters of tube side and shell
side .
18. 6.Reducing the size of condenser by maintaining the efficiency.
7.Decreasing the viscosity of sulphur below 0.9 poise which will
lead to higher heat transfer in tube side . .
19. To achieve the goal of increasing the efficiency we need
to work in following areas :
1. Process knowledge .
2. Existing process evaluation.
3. Process modification leading to a suitable process in order to
meet the new emission requirements.
4. Decrease capital and operating costs.
