Methane to Syngas: Jan Lerou, Jan Lerou Consulting, LLC

Methane to Syngas

Jan J Lerou

Jan Lerou Consulting, LLC

March 7, 2016

Methane to syngas process technologies



Commercial technologies

 Steam reforming

 Partial oxidation

 Non-catalytic partial oxidation

 Auto-thermal reforming

 Catalytic partial oxidation



Almost commercial technology

 Short Contact Time – Catalytic Partial Oxidation

 Oxygen Transfer Membranes – Praxair

 Dry Reforming



Emerging Technologies

 Chemical Looping

SMR Technology



Conventional

technology



Capacity:

20 million standard cubic feet/day



Large Size:

SMR Technology Today

SMR Technology



Limitations

 Carbon formation at low steam/carbon

 High conversion requires high temperatures

 Excess steam production

 Cooling in waste heat boiler to avoid Boudouard carbon formation

 Low NO_x levels required in stack



Challenges

 Lower the steam/carbon ratio

 Low NO_x burners

 Material limitation in tube alloys

SMR Catalyst Technology

Supports:

α - and -Al₂O₃, MgO, MgAl₂O₄, SiO₂, ZrO₂, CeO₂, TiO₂ Active metals:

Mostly Ni - Ru, Rh, Pd, Ir, Pt

Partial Oxidation Technology

POX Technology



Limitations



Possibility of utilizing a “low value” feedstock

.



Reaction is exothermic (energy consumption is less)



Environmentally friendly in terms of exhaust gases:

little NOx production



Challenges



Oxidation step is highly exothermic, reducing the

energy content of the fuel



Cost of reaction materials are high



Soot can easily emerge in the non-catalytic POX

Auto-thermal reforming technology

ATR Technology



Limitations

 Cost of oxygen

 Limitation in H2 pressure

 Limitation in exit temperature

 Requires waste heat boiler to avoid Boudouard carbon formation



Challenges

 Lower the steam/carbon ratio

 Increase CH4 conversion by increasing temperature

 Carbon free burner operation

Comparison of the technologies

Method

Operating conditions

H2/CO

CO2 emissions Investment

Temp (0C) Press (bar) Relative Relative

SMR 750 - 900 15 - 40 3 - 5 100 100

ATR 850 - 1,000 20 - 40 1.6 - 2.65 74 60

Short Contact Time

–

Catalytic Partial Oxidation

SCT-CPO vs SMR for a 55,000 m3/d unit



Steam Reforming:

 Unit volume: approx. 11,000 m3

 Catalyst volume: 21 ton in 178 reactor tubes



SCT-CPO:

 Unit volume: approx. 70 m3

 Catalyst volume: 0.8 ton



Investment:

OTM Autothermal Reformer

OTM Technology

Impact of OTM Technology

Dry Reforming



Last decades catalyst development focused

on screening a new catalyst to reach higher

activity, better stability toward sintering,

carbon deposition (coking), metal oxidation,

and forming of inactive chemical species



Preferred catalytic metals:

 Ni, Ru, Rh, Pd, Ir, and Pt

 Ru & Rh have better activity and resistance to coking

 Ni less expensive but high carbon formation

 Co has shown potential although it is not as active

Dry Reforming

Dry Reforming



Few industrial applications

Chemical Looping Reforming

Chemical Looping Reforming

An alternative is to put a classical SMR reactor

inside the Chemical Looping Combustion loop

Tri-reforming

C. Song, Am. Chem. Soc. Div. Fuel Chem. Prep. (2000), 45 (4), 772-776

Tri-Reforming

Advantages

• Direct use of flue gases

• High methane conversion

• No CO₂ separation

• Desired H₂/CO

• Minimal coke formation

• Use of waste H₂O/O₂

• Simplified process

Disadvantages

• Requires oxy plant

• Novel process

• No commercial catalyst

• Requires high GHSV

• Heat & mass management

Tri-reforming

Catalysts primarily Ni based with many

variations on promoters and supports

Ni/Ce-ZrO

₂

& Ni/ZrO

₂

Ni/MgO, Ni/MgO/CeZrO,

Ni/Al

₂

O3

Ni/ -SiC, Ni/CeO2

Ni/(CeO2,La2O3)/Al2O3