Transcript Syngas Synthesis & Use

Syngas Synthesis & Use
Group 6: Jacob Hebert, Michael
McCutchen, Eric Powell, Jacob Reinhart
Syngas
• Short name for synthetic gas made up of hydrogen and carbon
monoxide
• Created by the process of gasification (biomass steam
reforming)
• CH4 + H2O → 3H2 + CO
• Main use is for the generation of electricity
Purpose of Syngas
• Syngas is an intermediate compound that
holds many valuable uses.
• Production of syngas has:
– opened up a wide variety of research
opportunities in renewable energy sources
– provided efficient production of other chemicals
– environmental benefits
– provided a safer fuel source
Use: Electricity Generation
• Steam reforming is used to produce a liquid called pyrolysis
oil, used like crude oil.
• Syngas has the ability to replace natural gas as a more
thermally efficient liquid fuel.
• Electricity can be generated from the power provided by the
combustion of syngas at the cost of zero carbon emissions
• This provides a much cleaner, economical, and renewable
source instead of our common reliability on natural gas.
http://biomassmagazine.com/articles/1399/syngas-101
Use: Gas Engines
• Syngas is considered a renewable fuel since its origins mainly
come from biological materials such as organic waste.
• Putting a carbonic waste stream through syngas synthesis
converts waste to power through combustion.
• Benefits include : renewable power, reduction of carbon
emissions, problematic wastes to usable fuel, and onsite
power production.
http://www.clarke-energy.com/synthesis-gas-syngas/
Intermediate for other compounds
• Methanol: Serves as a fuel that has a high octane rating, easily
distributable, and its low volatility
• Ammonia: use as a cleaning solution, fertilizers, and is used in
the production of many organic compounds like our
pharmaceuticals and plastics
Synthesis Methods
• Carbon feedstock is reacted with H2O and/or O2 to
produce H2 and CO in a process called Gasification
• Types of carbon feedstocks:
– Natural gas and Heavy Oil:
• Requires purification of methane and higher hydrocarbons
respectively
– Biomass and Coal:
• Requires pyrolysis prior to gasification
• Pyrolysis: decomposition of carbon material by heating in
the absence of oxygen
Gasification: Steam Reforming
• Steam Reforming:
– Feedstock reacts with steam to produce CO and H2
– CH4 + H20  CO + 3H2
ΔH = +206kJ/mol
– Results in CO:H2 ratio of 1:3
– Highly endothermic reaction
• Operating temperature can range from 800K to 1500K
• Heat generated by combusting part of feed stock or
external heating
• Catalysts used to enhance reaction kinetics
Pyrolysis Example
pyrolysis system for biomass
http://biomassmagazine.com/articles/10537/mobilizing-pyrolysis
Steam Reforming Example
Steam reforming plant: Texas City, Texas.
http://www.linde-engineering.com/en/process_plants/hydrogen_and_synthesis_gas_plants/gas_generation/steam_reforming/index.html
Gasification: Partial Oxidation
• Partial Oxidation:
– Feedstock reacts with oxygen to produce CO and
water; generated water reacts with feedstock
– CH4 + 0.5O2  CO + 2H2 ΔH = -38kJ/mol
– Results in CO:H2 ratio of 1:2, which is desirable for
methanol synthesis
– Exothermic, so requires less heat generation
Other Gasification Reactions
• Autothermal Reforming:
– Combines steam reforming and partial oxidation
into one process
– Can be used with CO2 feed to yield different CO:H2
• Water Gas Shift:
– Equilibrium reaction converting between CO and
H2
– CO + H2O ↔ CO2 + H2 ΔH = -41kJ/mol
– Control T and P for desired CO: H2 ratio
Room for improvement
• According to an article in Joshua Mackaluso in
Basic Biotechnology eJournal, some areas
requiring future research are:
– Reactor design and function must be optimized
– Downstream marketability of syngas and its
derived products and be improved
Steam Reforming - Challenges
• Controlling ratio of H2/CO, which can be
different for different applications (H2 storage,
alcohol synthesis)
• Achieving good conversion – need to balance
side reactions, thermodynamics, kinetics
• Need a good water source, can be a
geographical concern
• General catalyst concerns
Nickel catalyst
http://www.catalyst.net.cn/timemodel/product/2012-03-26/13769647.html
Partial Oxidation - Challenges
• Requires substantial O2 supply
• Very high temperatures (1400C)
• Generates byproducts which need to be
scrubbed (e.g. HCN)
… but no catalyst is used, so no issues with
catalyst poisoning, coking etc. and less to
consider with pressure drop, transport
properties etc.
Future for Syngas
• As stated in an article by Jessica Ebert of
Biomass Magazine “once you have syngas you
have optionality.” This is because “Syngas has
the building blocks to create all the products
and chemicals currently generated in the
petrochemical industry.”
Conclusions
• We can see that Syngas production while not
yet optimized is a very important product. It is
versatile and has a variety of uses.
• As research continues and reactors are
optimized Syngas may even become a primary
source of fuel; as mentioned it can replace
natural gas.
References
•
•
•
•
•
Synthesis Gas Chemistry and Synthetic Fuels - Syngaschem BV. (n.d.). Retrieved
February 5, 2015, from http://www.syngaschem.com/syngaschem
Synthesis Gas | Linde Engineering. (n.d.). Retrieved February 5, 2015, from
http://www.linde-engineering.com/en/process_plants/hydrogen
The magic of syngas. (n.d.). Retrieved February 5, 2015, from
http://www.chemrec.se/Syngas_the_link_from
Mackaluso, J. (n.d.). The use of Syngas derived from biomass and waste
products to produce ethanol and hydrogen. Basic Biotechnology EJournal, 3,
98-103. Retrieved from
http://large.stanford.edu/courses/2011/ph240/demori2/docs/236-1576-1PB.pdf
Anton, V. C. (2001). Fischer Tropsch: a futuristic view. Fuel Processing
Technology 71(1), pp. 149-155
https://web.anl.gov/PCS/acsfuel/preprint%20archive/Files/45_1_SAN%20FRA
NCISCO_03-00_0124.pdf