2. H2S REMOVAL AND SULPHUR CONVERSION PROCESS
This template can be used as a starter file for presenting training materials in a group setting.
Sections
Right-click on a slide to add sections. Sections can help to organize your slides or facilitate collaboration between multiple authors.
Notes
Use the Notes section for delivery notes or to provide additional details for the audience. View these notes in Presentation View during your presentation.
Keep in mind the font size (important for accessibility, visibility, videotaping, and online production)
Coordinated colors
Pay particular attention to the graphs, charts, and text boxes.
Consider that attendees will print in black and white or grayscale. Run a test print to make sure your colors work when printed in pure black and white and grayscale.
Graphics, tables, and graphs
Keep it simple: If possible, use consistent, non-distracting styles and colors.
Label all graphs and tables.

3. Contents Introduction to H2S Why H2S should be removed
Methods of removal of H2S
Flaring and sour gas collection
Hydrodesulphurization
Using iron-oxide and plasma
Gas stripping
Amine Treatment

4. H2S Conversion processes
Claus process
Recycle selectox process
Direct Oxidation Process
Lo-cat process
Stretford process

5. What is Hydrogen Sulfide?
Chemical Formula: H2S
Colorless gas with rotten egg odor
It can be produced by the bacterial breakdown of organic matter, often in water, as free oxygen must be absent.

6. Physical Properties Molar Mass: 34.8 g/mole Density: 1.363 g/L
Melting Point: 191 K
Boiling Point: 213 K
Flash Point: K

7. Why do petroleum Engineers Care?
Naturally occurring in many crude oils
Also produced in oil refining processes by the degradation of the sulphur containing compounds in crude oil.
Heavily regulated because of its high toxicity, so removal and containment is crucial in petroleum industry.

8. Hydrogen Sulfide: A Silent Killer
Highly Toxic 1. Concentrations of ppm are lethal. 2. Cardiovascular and respiratory failure. 3. Improper handling and storage conditions can increase H2S concentrations in containers.
OSHA Standards
Concentrations may not exceed 20ppm in general industry practices

9. Methods for H2S Removal from Crude Oil: Do Away With the Undesirables
Crude oil contains 0-3% sulphur.
Sources of S in crude oil: thiols, thiophenes, sulfides, disulfides.
H2S gas must be removed from crude oil before transport.

10. Adsorption Methods Surface phenomenon Physical phenomenon
Catalyst Used:
Animal Charcoal
Impurities stick to the walls of catalyst.

11. Absorption Methods Bulk phenomenon Chemical Nature Catalyst Used: MDEA
This phenomenon is more reliable and advantageous as compared to previous one. Because the regeneration of catalyst is more important in case of MDEA than Animal charcoal or silica gel.

12. Flaring and Sour Gas Collection
Light hydrocarbons and impurities captured in Rus
H2S in the headspace of tanks or wells is captured and flared off in emergencies
The SO2 product is a greenhouse gas further processed for S recovery.

13. Hydrodesulphurization
Must be done before hydrocarbon cracking; S will poison the cracking catalysts.
High T/high P with transition metal sulfide catalysts on alumina supports (Co/Mo).
Sulphur compounds are converted to H2S which are removed in subsequent units.

14. Methods:
Reaction with iron oxide
Treatment by plasma

15. Hydrodesulphurization

16. Crude Oil: Gas Stripping
Methods for H2S Removal

17. Stripping of Crude oil Stripping
Process in which we remove one or more components from liquid stream by vapour stream
Stripping of Crude oil
Liquid stream from top
Vapour stream from bottom
H2S transfer from liquid to gaseous

20. Methods for H2S Removal from Crude Oil: Gas Stripping
The H2S of crude oil was extracted to gas by hot stripping.
Stripping was carried-out at 80c ,30mint ,0.5L/m flow rate of N2 as carrier.
Storage tank.
Adsorption unit.

22. Methods for H2S Removal from Crude Oil :Amine Treatment
Different Amines are use in gas treating
DEA
MEA
MDEA
One of the most common Amine MEA(RNH2)
𝐑𝐍𝐇𝟐+𝐇𝟐𝐒⇄RN𝐇𝟑++𝐒𝐇+

24. Amine Treatment Downward flowing Amine solution
Upward flowing sour gas
Absorber and Regenerator

25. Sulphur conversion process
This template can be used as a starter file for presenting training materials in a group setting.
Sections
Right-click on a slide to add sections. Sections can help to organize your slides or facilitate collaboration between multiple authors.
Notes
Use the Notes section for delivery notes or to provide additional details for the audience. View these notes in Presentation View during your presentation.
Keep in mind the font size (important for accessibility, visibility, videotaping, and online production)
Coordinated colors
Pay particular attention to the graphs, charts, and text boxes.
Consider that attendees will print in black and white or grayscale. Run a test print to make sure your colors work when printed in pure black and white and grayscale.
Graphics, tables, and graphs
Keep it simple: If possible, use consistent, non-distracting styles and colors.
Label all graphs and tables.

26. Why we want to convert H2S into sulphur?
Toxic.
Corrosive.
Difficult to handle.
Transportation cost is high.

27. Sulphur is an extremely useful element. Its largest application is for:
Manufacture of fertilizers.
Rubber industries.
Cosmetics.
Pharmaceuticals.

28. Sulphur Process Selection

29. 1. Claus process Carl Friedrich Claus invented in 1883.
Reaction is exothermic, furnace temperature reached upto 1200 ºC and pressure above 70 KPa.
Condenser temperature is 150 ºC to 190 ºC.
Reheat Exchanger temperature is 200 ºC to 260 ºC.
Bauxite is used as a catalyst.

31. The process has many variations due to the feed gas conditions and compositions:
H2S concentration > 50% (straight through Claus)
H2S concentration < 50% (feed and air preheat)

32. Advantages of Claus process
Recoveries from 98.5 to 99.99%.
Lower operating costs than other sulphur recovery processes.
High purity, saleable sulfur.

33. 2. Recycle Selectox Process
Process developed by Parsons and Unocal.
Recover maximum Sulpher from gas containing 5 to 30% H2S.
Selectox catalyst dirctly catalyzes the oxidation of H2S to SO2 and also catalyzes Claus reation.
The exothermic claus reaction result in temperature rise of 30 ºC in 1st stage reactor and 15 ºC in 2nd stage reactor.
A Recyle blower dilutes the incoming acid gas with selectox condenser.

34. One Selectox stage followed by two Claus stage

35. 3. Direct Oxidation
H2S is oxidized with air over an alumina catalyst to form sulphur.
Recover sulfur from acid gas streams containing less than 15% H2S.
H2S is directly oxidized to sulfur at about 950 F.
Depending on the feed gas composition and sulfur recovery desired, a second direct oxidation reactor

37. References:
Petroleum refining technology by Dr. Ram Prasad