Cracking process

Project of Introduction to Petroleum and Gas Engineering and Explanation of the cracking process and types.Cracking, as the name suggests, is a process in which large hydrocarbon molecules are broken down into smaller and more useful ones,The cracking products, such as ethene, propene, buta-1,3-diene and C4 alkenes, are used to make many important chemicals. Others such as branched and cyclic alkanes are added to the gasoline fraction obtained from the distillation of crude oil to enhance the octane rating.

1. Contents : Thermal Cracking ------------- Steam Cracking ------------- Thermal Cracking process to produce gasoline ------------- Thermal Reforming ------------- Visbreaking ------------- Coking Catalytic Cracking Hydrocracking

2. Definition All hydrocarbon decomposition reaction In oil industry Heavy hydrocarbons with high boiling point of 200 ° c Decomposition of a gas or a light cutting oil

3. 1941: Standard Jersey developed the world’s first steam cracker at Baton Rouge. In 1891 The thermal cracking method was invented. modified in 1908 In 1934 factory of Shukhov cracking process established at Baku, USSR. History William Burton Vladmir Shukov

4. In 1923 The catalytic cracking method was invented In 19 42 FCC method was invented In Burton Rouge Refinery Companies: EXXON UOP M.W.KELLOGG

5. Thermal cracking The processes is which hydrocarbons are decomposed at elevated temperatures to from material of lower Mol. Wt

6. Thermodynamic Chart thermodynamic stability of hydrocarbons Hydrocarbons are unstable with respect to the elements at any temperature Unsaturated hydrocarbons to the corresponding saturated hydrocarbons are only stable at high temperatures. The stability of these compounds is reduced with longer hydrocarbon chain. Increasing the molecular weight reduction of thermal stability stability Paraffin < olefin< naften <aromatics.

7. aromatic stability Cracking activity

8. Kinetics Thermal cracking conversion increases with temp. and residence time Under very severe thermal cracking conditions, there is tendency for coke formation

9. Cracking goal

10. Contents : Thermal Cracking ------------- Steam Cracking ------------- Thermal Cracking process to produce gasoline ------------- Thermal Reforming ------------- Visbreaking ------------- Coking Catalytic Cracking Hydrocracking

11. Steam cracking In the process of steam cracking of thermal decomposition (pyrolysis) of saturated hydrocarbons (natural gas and oil cut) is done in the presence of water vapor. Production of unsaturated hydrocarbons such as ethylene and propylene and butane Products , raw material is petroleum.

12. A wide variety of feed used for pyrolysis United States natural gas ( ethane , propane) European countries and Japan cutting crude oil Feed

13. Chemistry of steam cracking Propagation Initiation Termination   + C + etc.   etc.  

14. Motivation for steam cracking The worldwide demand and production of olefins… Currently, production through steam cracking 94% of the world propylene. 2. In Western Europe, 95% of ````` ethylene and 70–75% of 111 propylene. 3. In Asia, 61% of ethylene. *source-2011-november_Olefinek eloallitasa.pdf

15. Overall a cracking process consists of two main components Hot Section Pyrolysis Cold Section Products , separation and purification

16. Process of steam cracking Pyrolysis section Fractionation and Compression Section Product recovery and Separation Section Naphtha

17. Hot section

18. designed to increase quickly temperature of feed Tubes must be resistant to corrosion and high temperatures . The quenching operation, heat is recovered. Furnace

19. Thermal flux (Kcal / m². h) Conversion (%) Mass flow (Kg / m². s) Feed Internal diameter of pipe(mm) 20000 – 25000 50 – 60 110 – 130 Ethan 100 12000 – 15000 70 – 85 130 – 140 propane 100 9500 – 12000 75 – 90 140 – 160 butane 100 950 0 – 12000 50 – 58 120 – 130 Gasoline 115

20. Pressure(Kg / cm²) Temperature(° C) Product feed .2 - .5 1000 – 1400 Acetylene Ethan .2 – 2 800 - 850 Ethylene Ethan .2 – 2 770 - 800 Propylene , Ethylene Propane , butane .5 - 2 720 - 770 Propylene , Ethylene Light Gasoline .5 - 2 720 - 750 Propylene , Ethylene Light Gas oil

21. Separation section Ethylene (24%) Propylene(20%) Butadiene(3%) BTX(1%) Petroleum ether(25%) Products from separation section

22. Cold section

23. Energy analysis in steam cracking sections Section Energy required Energy loss pyrolysis 65% 75% fractionation and compression 15% 25% recovery section 20% 15% “ Steam cracking is the most energy-consuming process in the chemical industry and globally uses approximately 8% of the sector’s total primary energy use.”

24. Thermal Cracking ------------- Steam Cracking ------------- Thermal Cracking process to produce gasoline ------------- Thermal Reforming ------------- Visbreaking ------------- Coking Catalytic Cracking Hydrocracking

25. Thermal Cracking process to produce gasoline:

26. Intensity of operation :

27. Thermal Cracking ------------- Steam Cracking ------------- Thermal Cracking process to produce gasoline ------------- Thermal Reforming ------------- Visbreaking ------------- Coking Catalytic Cracking Hydrocracking

28. Thermal Reforming Thermal reforming means cracking of gasoline in order to improvement of “Octane Number” & increase it’s “volatility” It work @ a classic system at Extreme operating conditions : P =20 to 70 Kg/cm² T = 510 ͦ ᶜ to 580 ͦ ᶜ No Reflux

29. Thermal Cracking ------------- Steam Cracking ------------- Thermal Cracking process to produce gasoline ------------- Thermal Reforming ------------- Visbreaking ------------- Coking Catalytic Cracking Hydrocracking

30. Visbreaking The viscosity reduction is a relatively mild thermal cracking to reduce viscosity and pour point is used . The aim is to reduce the viscosity of the fuel, without any significant change in its stability. The main cause of high viscosity is long paraffin chains attached to aromatic rings. Intensity of cracking is low

31. Reactions: Break off the chains of cyclo-paraffin and aromatic Gum converts to light hydrocarbons Naphthenic rings Cracking @ T>900 °F Operations : Furnace Soaker Temperature Residence time Stop unit Fuel used Furnace 890-930 1-3 min 3-6 month %80 of operation costs soaker 800-830 More than 3min 6-18 month %50 of operation costs Visbreaking

32. A unit of reduce viscosity (Soaker) ) Visbreaking

33. Thermal Cracking ------------- Steam Cracking ------------- Thermal Cracking process to produce gasoline ------------- Thermal Reforming ------------- Visbreaking ------------- Coking Catalytic Cracking Hydrocracking

34. Coking Convert heavy cuts to coke &… coke Methods Sponge coke Needle coke Shot coke Delayed Coking Fluid Coking Flexicoking

35. Coking -> Delayed Coking Accumulator Fractionator Naphtha Gas P/A Steam Stripper Steam Light gas oil Steam Heavy gas oil Feed Steam Gen. Condensate Drum Coke Heater Decoking Waterjet Coke Drum

36. Coking -> Fluid Coking Is newer than delayed coking Produce powder coke

37. Coking -> Flexicoking

38. Thermal Cracking ------------- Steam Cracking ------------- Thermal Cracking process to produce gasoline ------------- Thermal Reforming ------------- Visbreaking ------------- Coking Catalytic Cracking Hydrocracking

39. Catalytic Cracking in Refining Industry A

40. Introduction: E Houdry began his studies on catalytic craching & an industrial unit was built in the U.S. in 1936 Most important process since 1940 that mainly used for the production of gasoline from high boiling temperature such as heavy distillate ,olefinic light hydrocarbons , gas oil,… Production of 45% gasoline in the world

41. Catalytic Cracking vs Thermal Cracking : Better selectivity in the cracking operation gives less of the light-end substance More isomerization of the olefins occurs Saturation of the double bonds is better controlled Diolefin production is less Aromatic production is better Coke is formed more economically Ability to tolarete high-sulfur charge increase

42. Production of methane & ethane is less Production of propane & butane is more The formation of heavier oil & tars is minimized In the catalytic cracking hydrocarbons crack 50-60 time rapidly than no catalytic operations

43. Operation Variable: PRESSURE :AT 25 psig TEMPERATURE : 860-968 F in Reaction & 1000-1300 F in Regeneration Space Velocity Catalyst to oil ratio

44. Parts of catalytic cracking: 1-CRACKING 2-REGENERATION 3-FRACTIOANATION

45. Reactors in Cat cracker: 1.FIXED BED REACTOR 2.MOVING BED REACTOR 3.FCC OR FLUID CATALYTIC CRACKING

46. Fixed bed reactor: Disadvantage! : Complete vaporization of feed Equilibrium never is reached Temperature variation!

47. Moving bed reactor(TCC): Condition Operation: 10 psig Pressure 850-925 F

48. FCC: 1 IV…..Exxon research 2 Uopfluid Catalytic Cracking 3 Texaso Fluid Catalytic Cracking

49. Thermal Cracking ------------- Steam Cracking ------------- Thermal Cracking process to produce gasoline ------------- Thermal Reforming ------------- Visbreaking ------------- Coking Catalytic Cracking Hydrocracking

50. For the first time, Farben company applied Hydrocracking method for gasoline producing and it has been very conventional process, recently. because :

51. the most important property of hydrocracking is high hydrogen pressure.

52. reactions : 1 ) Chain breaking (simple hydrocracking reaction) 2 ) De-alkylation 3 ) Ring breaking olefins and aromatics hydrogenation reactions occur In Hydrocracking but these are not main reactions.

53. Thermodynamic studies cracking endothermic Reactions hydrogenation exothermic exothermic > endothermic less than 500 C therefor, reaction occurs high hydrogen pressure

54. Thermodynamic studies : Type of reaction heat of reaction(400 C) Hydrocracking 1) paraffins 2) naphthenes 3) aromatics Kcal/mol 11-14 10-12 10-11 Hydrogenation 1) olefins 2) aromatics 27-31 48-52

55. Kinetics studies : hard operating conditions -ring breaking occurs just after hydrogenation branched hydrocarbon Iso-alkane production increasing naphthenes

56. Kinetics studies : - rate of reaction and feed molecular weight relationship

57. Catalyst : metal : Pt , Al , Pd , W , Ni Catalyst acid-base : silicon-aluminum (crystal or zeolite) Catalyst activity is reduced by coke , Nitrogen and Sulfur composition.

58. Methods Two basic methods for Hydrocracking: 1) Fixed Bed Catalytic Hydrocracking 2) Fluidized Bed Hydrocracking

59. Methods company Method Standard Oil Co. and U.O.P (Isomax) Union Oil Co. (Unicracking) Exxon Research and Engineering (G. O. Fining) Gulf Oil Co. and houdry Process (H. G. Hydrocracking) Texaco (H – Oil) F.B.Hc C – E Lummus (LC – Fining) F.B.Hc Shell Development Co. (Shell) Badische Anilin and institute Francais du Petrole (BASF – IFP Hydrocracking) U.O.P ( Unibon )

60. Methods main equipment sections for Hydrocracking : Reaction section with one (or two) reactor. Separation section with separator or stabilizer columns

61. Fixed Bed Catalytic Hydrocracking Tow processes are defined for this purpose:

62. Single-stage

63. Two-stages

64. Fluidized Bed Hydrocracking ‘H – Oil’ and ‘LC – Fining’ processes Fluidized bed Hydrocracking is designed for heavy feed. Pressure is approximately 200atm. Depends on feed and rate conversion, temperature is between 420-450  C. The great advantage of this process : catalyst utilization

65. LC – Fining

66. Operating parameters Temperature Pressure 3) Volume space velocity space velocity  refers to the quotient of the entering volumetric flow rate of the reactants divided by the catalyst bed volume.

67. Hydrogen consumption Feed molecular weight Production molecular weight Hydrogen consumption Percentage of Sulfur in feed Consequently

68. Productions Generally, hydrocracking is a process as purpose of gasoline, gasoil and jet fuel producing. In the USA, it is based on gasoline production and in Europe, it is based on jet fuel and gasoil production .