This document provides an overview of Fischer-Tropsch synthesis technology for producing synthetic fuels and chemicals from natural gas and other resources. It discusses the key steps which include gasification of resources to produce syngas, reforming of natural gas to syngas, water-gas shift reaction, and the Fischer-Tropsch synthesis over catalysts to produce liquid fuels and waxes. It also summarizes different catalyst types including iron and cobalt catalysts used in the Fischer-Tropsch process and compares various reactor configurations for the synthesis.

1. 1
In the name of God
Fischer_Tropsch
synthesis
department of Chemical engineering
Isfahan university of technology
2017

2. 2
Presented by :
Shadi Razmara
(shadi.razmara16@gmail.com)
department of Chemical engineering
Isfahan university of technology
Isfahan - Iran

3. syngasIntroduction catalyst reactor conclusion
content
3

4.  What is XTL technology ?
• Easy transporting
• High quality
• Expensive products
• High reserves of natural gas
• Low environmental problems
Why we use XTL ?
4

5. Coal
Biomass
gas
Fuel &
chemical
X LiquidTo
refininggasification FTS
syngas FT wax & …
5

6. 6

7. 7

8. A Mixture of CO &
Hydrogen(and very often
co2)
An intermediate to
produce other chemicals
What is syn Gas ?
8

9. COAL
BIOMASS
NATURAL GAS
9

10. 10
1

11. Fredrich
Bergius
1913
 Producing synthetic fuels from coal
 Flammability less than oil
 Coal is one of the most abundant sources of energy
 Coal is inexpensive when compared to other fossil fuels (or alternative energy sources)
coal
11

12. The process of converting :
coal & biomass
to syn Gas 
Natural gas
to syn Gas 
Solid &
heavy liquids
Gas &
light liquids
12

13. 13
A. reforming

14. Natural gas
 is a gas consisting primarily of methane
Also contains other hydrocarbons – ethane, propane,…
 It is an important fuel source, a major feedstock for fertilizers,
and a potent greenhouse gas
 Natural gas is used extensively in residential, commercial and
industrial applications
14

15. Distribution of natural gas
by countries in cubic metres per year
15
2

16. purification
nitrogen
CO2
H2S
Heavy
hydrocarbons
16

17. Steam Reforming(SMR)
• CH4 + H2O → CO + 3H2 (Ni Catalyst)
• H2/CO = 3
• Endothermic
• Favored for small scale operations
Partial Oxidation(POX)
• CH4 + ½O2 → CO + 2H2
• H2/CO ≈ 1.70
• Exothermic
• Favored for large scale applications
Auto thermal Reforming(ATR)
• A combination of Steam Reforming and Partial Oxidation
type of Reforming
17

18. 18

19. Drying and removing moisture
Pyrolysis reactions
Gasification or regeneration
Burning or oxidation
Gasification process
19

20. Gasification reactions
C+𝐇 𝟐 𝐎 ⇒ 𝐂𝐎 + 𝐇 ΔH = 119
K J
mol
C +
𝟏
𝟐
𝐎 𝟐 ⇒ 𝐂𝐎
ΔH = −123
K J
mol
𝐂𝐎 + 𝐇 𝟐 𝐎 ⇒ 𝐂𝐎 𝟐 + 𝐇 𝟐 ΔH = −40
K J
mol
C + 𝟐𝐇 𝟐 ⇒ 𝐂𝐇 𝟒 ΔH = −206
K J
mol
20

21. Types of Gasifier : •Fixed Bed Gasifier
Fixed Bed Gasifier
Fluidized bed Gasifier
Entrained Flow Gasifier
21

22. Entrained Flow Gasifier:Fluidized bed Gasifier:
22

23. Types of secondary reactions:
Secondary reactions of alpha olefins:Hydrogenation of olefins to
paraffin
Isomerization
Cracking
Hydrogenolysis
23

24. Water-Gas Shift Reaction:
The Format Mechanism
Direct oxidation mechanism
CO + H2O ⇒ CO2 + H2
24

25. Effective factors on secondary reactions :
penetration: Infiltration constraints affect the movement of reactive
substances to active catalytic sites, as well as the disposal of products from these
active sites.
Solubility:The liquid and vapor levels and high-boiling point products for
the proper design of phase-gas processes and kinetic modeling of this kind of
Hanoi reactor.
Physical Adsorption: Physical absorption is an intermediate state
between chemical absorption and gas flux under the influence of Van der Waals
gravity forces. 25

26. 26

27. Competitive dissociative adsorption
Relatively high hydrogen
coverage methanation
27

28. Required :
*Dissociation of carbon monoxide
*Removal of adsorbed oxygen by reaction to either carbon dioxide or water
*Limited availability of adsorbed
hydrogen
28

29. Catalysis
*Based on VIIIB metals
Iron(Fe)
_low cost
_higher water gas shift activity
_suitable for lower syngas(H2/CO)
Cobalt(Co)
_more active
_less water gas shift activity
_higher cost
_suitable for high syngas(H2/CO)
_temperature sensitive 29

30. Water-gas-shift(WGS)
30

31. catalysis
Nickel(Ni)
_Promotes methane formation
_volatile carbonil production
Ruthenium(Ru)
_high cost
_not generaly used
31

32. Catalyst in industrial scale
32

33. cost
33

34. Co catalyst
34
3

35. Effect of support in structure and revenue of
‘Co’ catalyst
Increase contact surface
Dispersion , dimensions of little bits
ability to improve catalysts
Negative effect : reduction of supported
precursor to metal particles
To penetration reactors in to catalysts
35

36. 0
50
100
150
200
250
300
0 50 100 150 200 250 300 350 400
dimensionofcrystal(A)
diameter of injuries(A)
effect of injury dimension
36
4

37. Effect of promoter
Electronic promotion
Increases intrinsic cobalt activity
Changes in electronic environment of
cobalt
Structural promotion
No effect on intrinsic cobalt activity
Increase surface area of Co, thus increasing
rate
37

38. 38

39. Use of this catalysts in operational conditions of high temperature and
low temperature of Fischer-Tropsch synthesis.
•General reaction is:
CO + 2H2 (-CH2-) + H2O
39

40. 40

41. •Most activity
Active locations include iron
carbides In the reaction of the
Fischer-Tropsch synthesis
Active locations of Magnetite
(Fe3O4) in the shift reaction of
water - gas
41

42. •The famous reaction of Budard is:
CO + CO C + CO2
Disproportionate sharing of
(CO)
Production of carbon on the surface
of the catalyst
42

43. At the beginning of the
reaction and after the
reduction
Mainly contains metal
iron
While doing the reaction
Convert to Iron and
Magnetite carbides
43

44. Fe(NO3).9H2O Fe2O3 / SiO2 (Fe3O4 + FexC)/ SiO2
SiO2
T=773K
Air
CO/H2
T=623K
P=0.3 MPa
Catalyst
P=2.0 MPa
CO/H2
T=523K
FexC (+ Fe3O4)FT (+WGS)
P=2.0 MPa
CO/H2
T=583K
Fe3O4 (+ FexC)WGS (+FT)
Catalytic
reaction
Calcination and activation processes of catalyst
Structural changes of iron catalyst during the resuscitation process
44

45. •The two-stage process of hematite reduction to
metal iron
3Fe2O3 + H2 2Fe3O4 + H2O
Fe3O4 + 4H2 3Fe + 4H2O
45

46. Evaluation of the possibility of revival hematite to
metal iron
Thermodynamic relationship of
the revival process ΔG = nRT ln[(PH2O/ PH2)/(PH2O/ PH2)eq]
46

47. Using of nitrogen as a diluent with hydrogen when
revival of the iron catalyst
Leaving the water generated
from the catalyst surface and
reduction of partial pressure of
water
Increasing of
spatial speed
Special thermodynamic
conditions of iron
Conversion of iron carbides
in the presence of water
production water from the
reaction, to Iron oxides and
deactivation of catalyst
47

48. Investigation of the planned temperature revival of Iron
catalysts
The presence of Cu in Iron catalysts
1) Facilitate of the reduction process (Fe2O3 to Fe3O4)
2) Doing the reaction at lower temperature
3Fe2O3 + H2 2Fe3O4 + H2O
CuO + H2 Cu + H2O
48

49. Schematic of reduction process of Iron catalyst with Cu
RepulsedH2
T(°K)
49
5

50. Structural changes of Iron catalysts during the process of
carbidizing and Fischer - Tropsch synthesis
Inactivation of the metal
Iron
Convert to Iron carbide
50

51. Structural changes of Iron catalysts during the process of carbidizing
Fe2O3
Fe3O4 (FM) Fe3O4
Fe3O4 (SP)
Fe2O3
Fast
(Hematite)
Activated by
H2 ,H2/CO
or CO
Fe3O4
(Magnetite)
α-Fe
H2/CO
FexC
H2
CO
H2/CO
Carbides
Carbide catalyst
and activated
Fe3O4
Super gravity (SP)
Calcined catalyst of
super gravity of Fe2O3 (SP)
51

52. 1) The precipitated Iron catalysts that used in fixed bed and dredging bed reactors at low
temp synthesis of Fischer – Tropsch
2) The fused Iron catalysts that used in fluid bed reactors at up temp synthesis process of
Fischer – Tropsch
Using of 2 types of Iron catalysts at developed industrial
processes:
52

53. Comparison of Co and Fe
53
6

54. Reactors
•high temperature synthesis -2phase
Fixed fluidized reactors
Moving fluidized reactors
•low temperature synthesis-3ph-wax pr.
Fixed bed reactors
Slurry reactors 54

55. Fixed bed reactors
•Catalyst is in tubes with small
diameter
•T=493-523K
•P=2.7MPa
•High wax production
•Simple condition operation
55

56. 56

57. Fluidized bed reactors
•Fixed fluidized bed reactors
•T=593K
•P=2.7MPa
•1.5 recycle ratio
•High yields
•Good temperature control
•High throughput
57

58. 58

59. Fluidized bed reactors
•Moving fluidized bed reactors
•T=593-633
•P=2.7MPa
•Catalyst lasts about 40 days and is replaced
•High consumption energy
59

60. 60

61. Slurry reactors
•Low reaction temperature
•High wax selectivity
•Most flexible design
•Low operation cost
61

62. 62

63. Comparison of reactors (selectivity)
•High yields in:
•Waxes: isothermal fixed bed and slurry reactors
•Gasoline :fluidized bed and slurry reactors
•Light products: fluidized bed reactors
63

64. 64

65. Comparison of petroleum & GTL products:
Product type Quality factor GTL Refining crude oil
NAPHTHA Density(g/ml) 0/69 0/74
Sulfur(%) 0 0/07
KEROSENE& JET FUELS
Density(g/ml) 0/77 0/8
Sulfur(%) 0 0/12
Smoke point 45 22
Freezing point(°F) -53 -53
Gasoline
Density(g/ml) 0/78 0/84
Sulfur(%) 0 0/37
Aromatics (%) <0/1 29
setan number >70 56
Viscosity(c estoks) 2/3 4 65
7

66. Product upgrade processes:
Effective factors
Feed type
The catalyst
Operating conditions
66

67. High boiling temperature
process
Branched and
Olefinic compounds
+a few Aromatics
Butane & Propylene
Low boiling temperature
process
Dense hydrocarbons
Heavy Paraffin
Products
67

68. HTFT
Hydrocracking
Isomerization
Hydrogenation
oligomerization
Turning Light to Heavy Products
Turning heavy to low boiling temperature
products
improving density & octane number
removing oxygen contents
68

69. Product process(low temperature)
69

70. GTL plants :
• Sasol plant: Sasolburg in south Africa
(high temperature technology)
Use of fixed bed Arge reactors heavy products
Use of fluidized bed Synthol reactors fuels(Gasoline&LPG)
Capacity : 160000 bbl/day
• Shell plant : Bintulu in Malaysia Use a three-step process(Advanced gas
conversion)
capacity: 12500 bbl/day
70

71. 71
8

72. Countries Owning Production Technology
The largest producer
since 2011
72

73. GTL IN IRAN:
•Owning 18.2% of natural gas resources) Second place in the world)
•Failure to optimal use due to inaccessibility of proper use and lack of processing
•GTL Units under construction:Kermanshah & Asaluyeh
•Iran in terms of natural gas consumption in the third place after the US and
Russia
73

74. COST FOR PLANTS:
•Syngas generation 65-70% The most expensive stage air
separation
•Fischer-tropsch syn. 21-24%
•Upgrading to fuels 9-19%
74

75. Investment
The total price of a unit for 30000 bbl/day=
24000-50000$
Technologic
al type
product type &
scale
Geographic
location
Factors of
Economy
Feed price
Tax
restrictions
Crude oil
price
75

76. Increase profitability
Use of
gas in oil
fields
Highest
quality
Minimum
cost
cheaper gas
feedstock
Maximum
Capacity
76

77. 77
References
1.Steynberg,A.P & M. E. Dry. ‘’ fischer tropsch technology’’ NO 152.Amsterdam , Elsevier,2004
2.http://www.mizenaft.com/fa/doc/news/13767
3. https://www.omicsonline.org/hydrogenation-of-co-on-cobalt-catalyst-in-fischer-tropsch-synthesis-2157-
7544.1000113.php?aid=4732
4.Khodakov, A. Y. ‘’FT synthesis : relation between of cobalt catalyst & their catalytic performance . 144 p. 251
5.J .Xu .C . H . Bartholomew . ‘’temperature programmed hydrogenation . J . Phys. Chem . B 109. p.2392
6. Design, synthesis, and use of cobalt-based Fischer-Tropsch synthesis catalysts (Iglesia, 1997)
7. ‫ایران‬ ‫انرژی‬ ‫نشریه‬/‫هشتم‬ ‫سال‬/‫شماره‬18/‫ال‬ ‫تی‬ ‫جی‬ ‫فناوری‬ ‫اقتصادی‬ ‫بررسی‬
8. ‫نفت‬ ‫صنعت‬ ‫تجهیزات‬ ‫نشریه‬/‫شماره‬1
9.www.fischer-tropsch.org
10.High quality diesel via the Fischer–Tropsch process – a review (Dry, 2001)
11. ‫سنتزی‬ ‫های‬ ‫سوخت‬ ‫تولید‬ ‫برای‬ ‫راهی‬ ‫تروپش‬ ‫فیشر‬ ‫سنتز‬.‫پور‬ ‫نخعی‬ ‫علی‬.‫نفت‬ ‫صنعت‬ ‫پژوهشگاه‬

78. 78
Thank you!