STEAM REFORMING PROCESS
UHDE AND MEMBRANE TECHNOLOGY

Group: Vũ Thị Thanh
Kim Ngọc Thông

A.Prof : Phạm Xuân Núi
Contents
1. Introduction
2. Steam reforming process
2.1Feedstock
2.2 Mechanism of catalyst
3. Steam reforming process through Uhde technology and membrane technology
3.1 Uhde technology
3.2 Membrane technology
4. Conclusion
Introduction
Steam reforming process

Synthesis gas
( Hydrogen, Carbon monoxide)

Synthesis methanol, synthetic fuels in the Fischer- Tropsch synthesis , amonia synthesis
Steam reforming process

1. Feedstock
Feedstock including natural gas or naphtha. 
Natural gas 




Naphtha normally refers to a number of liquid mixtures of hydrocarbons.

Steam reforming process –Technology

Feedstock purification
The catalysts used are poisoned by trace components in the hydrocarbon feed, particularly sulphur, chlorine and metal compounds
Desulfurization : Sulphur is converted in to H2S, then adsorbed stoichiometrically by ZnO at 400oC.
Removing chloride: If the amount of Cl > 1ppm , alkali will be used to adsorb.



Steam reforming process

2. Mechanism of steam reforming

Steam reforming process- Mechanism catalyst













1. RS + H2 → H2S + RH Co - Mo/Al2O3
2. H2S + ZnO → ZnS + H2O






Hydro desulfurization- Mechanism



Adsorption of hydrogen near vacancy
H2 + MoS2 → MoS2-H
Adsorption of RS on vacancy
RS + → R-S-
Hydrogenolysic of C-S bond
 RC-SH- + H2 → RCHad + H2S-
Desorption of H2S to create vacancy
H2 + 2Mo+4 + S2- → H2S + 2Mo+3 +
Finally H2S- → + H2S

RS + H2 → H2S + RH Co - Mo/Al2O3
Steam reforming – Mechanism
2CH4 + 3H2O ↔ 7H2 + CO + CO2 Ni/CaAl2O4

1) CH4 + 2* → CH3* + H*

2) CH3* + * ↔ CH2* + H*
 
CH2* + * ↔ CH* + H*

4) CH* + * ↔ C* + H*
5) H2O + 2* ↔ HO* + H*
 
6) HO* + * ↔ O* + H*
 
7) C* + O* ↔ CO* + *
 
8) CO* ↔ CO + *
 
9) 2H* ↔ H2 + 2*


Water gas shift- Mechanism
CO + H2O → H2 + CO2 Fe3O4 – Cr2O3
CuO


1) H2O + * ↔ H2O*
 
2) H2O* + * ↔ HO* + H*
 
3) 2HO* + * ↔ H2O* + O*

4) HO* + * ↔ H* + O*
 
5) 2 H* ↔ H2 + 2*
 
6) CO + * ↔ CO*
 
7) CO* + O* ↔ CO2* + *
 
8) CO2* ↔ CO2 + *

Uhde technology
Uhde reformer
The tubes of the Uhde reformer consist of a centrifugally-cast high alloy steel with a high creep rupture strength. This allows a lower wall thickness, results in lower thermal stress and also enables a high heat flux. Temperature in tube = 850 -1000oC.
Manifold modules
Manifold system in operation
Cold outlet manifold system
Gas cooler
Process gas cooler with steam drum
Internal by pass arrangement
Water gas shift reaction
The HWGS has typical inlet temperature range of 320-350oC. Toward the outlet it rises to approximately 420oC due to the exothermic nature of the reaction.
Adding an LWGS reactor, where the components react adiabatically at a typical inlet temperature of 200oC.
Membrane technology
Oxygen transport membrane (OTM) and a hydrogen transport membrane (HTM)
Ion transport membrane (ITM)
Conclusion
Catalysts take an important role in reforming process(Catalysis deactivation or poison of catalysis which in fact is definitely the problem of this process need to be concerned)
Organizing technology is more considerable and improved to get more efficiency.
Membrane technology can be applied to get lower cost production.
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