4. What is XTL technology ?
• Easy transporting
• High quality
• Expensive products
• High reserves of natural gas
• Low environmental problems
Why we use XTL ?
4
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
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
23. Types of secondary reactions:
Secondary reactions of alpha olefins:Hydrogenation of olefins to
paraffin
Isomerization
Cracking
Hydrogenolysis
23
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
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
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
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
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
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
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
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
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
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
67. High boiling temperature
process
Branched and
Olefinic compounds
+a few Aromatics
Butane & Propylene
Low boiling temperature
process
Dense hydrocarbons
Heavy Paraffin
Products
67
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
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