The document discusses molten carbonate fuel cells (MCFCs). It provides details on their history, operation, advantages, and applications. Some key points: - MCFCs were first experimented with in the 1930s but did not become viable until the 1950s when molten carbonate electrolytes were used. - They operate at high temperatures (650°C) using hydrogen, oxygen and carbon dioxide as reactants to generate electricity through an oxidation-reduction reaction. - Advantages include high efficiency (65%), carbon dioxide capture/storage abilities, and not requiring precious metal catalysts. Applications include power generation and carbon capture from industrial processes.

1. Daniel​ ​Prakash
Liam​ ​Ramsay
11/17/2017
Molten​ ​Carbonate​ ​Fuel​ ​Cells
Presentation:
● Liam:​ ​Slides​ ​(1,​ ​2,​ ​3,​ ​4,​ ​5,​ ​12,​ ​13)
● Daniel​ ​Slides​ ​(6,​ ​7,​ ​8,​ ​9,​ ​10,​ ​11,​ ​14);
Report:
● Liam:​ ​Pages​ ​(Abstract,​ ​Introduction,​ ​Advantages)
● Daniel:​ ​Pages​ ​(Disadvantages,​ ​Applications,​ ​Conclusion)

2. ABSTRACT
Research into solid oxide electrolytes have been conducted since the 1930’s and research today
shows the potential in molten carbonate fuel cells. They provide electrical power by an
oxidation-reduction reaction with oxygen, hydrogen and carbon dioxide gases as the reactants. The
intermediate compound in the reaction that drives the process is our molten carbonate electrolytes. The
advantages that this system provides includes reduced costs, high efficiency and less vulnerability to
carbon monoxide poisoning. However, the most important advantage is the fuel cell’s ability to pull
carbon dioxide out of the air and convert it into a higher concentration that can be cooled into a liquid
capable of being recycled back underground. However, it is not a perfect system as there are
disadvantages such as high temperature corrosion and high intolerance to sulfur. Many new systems are
applying this fuel cell as a method to generate large amounts of power while also taking carbon dioxide
out​ ​of​ ​the​ ​atmosphere​ ​as​ ​way​ ​to​ ​reduce​ ​the​ ​effects​ ​of​ ​climate​ ​change.
INTRODUCTION
The concept of using high temperature electrolytes in fuel cells have been explored since the
1930’s. As such, both molten carbonate and solid oxide fuel cells fit this description and as such share an
overlapping history in their development.. Their lines of research match very similarly and it was not until
the late 1950’s that their histories diverge into their own methods of fuel cell energy. Beginning with the
1930s, Scientists Emil Baur and H. Preis of Switzerland experimented high-temperature, solid oxide
electrolytes as a method to generate electrical current as a power source. However, these Swiss scientists
encountered issues with electrical conductivity unable to be great enough to generate a large enough
charge to supply power. Another issue of their system included unwanted chemical reactions between the
electrolytes and various gases interfering with the processes in the fuel cell. One of these gases of interest
includes carbon monoxide which is still an issue for many fuel cells today and need to be accounted for to
ensure the operation of the system: back then, this issue was not solved by the Swiss scientists but by
future minds. Following the 1930’s, scientist O. K. Davtyan of Russia explored this solid oxide
electrolytes further however his research gained little success however his work gave right to future
motivation in exploring this method of fuel cells. By the late 1950s, Dutch scientists G. H. J. Broers and J.
A. A. Ketelaar designed and built a system based on this previous work of solid oxide electrolytes and
concluded that their limitations at that time made short-term progress implausible and as a result, these
scientists changed their focus toward electrolytes of fused or molten carbonate salts. In their scientific
reports, they noted constructing a cell that managed to operate for six months utilizing an electrolyte
"mixture of lithium-, sodium- and / or potassium carbonate, impregnated in a porous sintered disk of
magnesium oxide" by 1960. From their research, it is worth mentioning that they discovered that they
found the amount of molten electrolyte was slowly decreasing. They concluded that this is partly through
the observed reactions with materials of the gasket. Around the same time as these scientists had built
their fuel cell, Francis T. Bacon conducted his own work with a molten carbonate by designing a cell that
consisted of two-layer electrodes on either side of a "free molten" electrolyte. Further research continued
as two groups focused directly on semisolid or "paste" electrolytes and while most other groups were
looking toward "diffusion" electrodes. These electrolyte providers would replace the originally used solid
ones. Once in the mid-1960s, the U.S. Army's Mobility Equipment Research and Development Center

3. (MERDC) at Ft. Belvoir investigated several molten carbonate cells manufactured by Texas Instruments
as effective MCFCs. The designed fuel cells varied in size from the smallest being 100 watts to the largest
being 1,000 watts output. The fuel cells were designed to operate on a fuel named as "combat gasoline.”
This fuel would require an external reformer to extract hydrogen that would be used as a reactant in the
power system. However, the Army was not interested in having a system that required a fuel that would
not be as readily available. This is mostly concerning for field units that would be unable to acquire this
fuel​ ​if​ ​need​ ​be.
Next, we continue by looking closely at how the MCFC actually works as a fuel cell.
Chemically, the system’s reactants includes hydrogen, oxygen and low concentrated carbon dioxide gases
which result in the products of water and high concentrated carbon dioxide. Focusing on the cathode first,
one oxygen molecule and two carbon dioxide molecules are taken from the atmosphere and enter the
cathode. Four electrons are added to the two reactants once in the cathode and produce the carbonate ions
as a product. Acting as an intermediate molecule, the carbonate ions leave the cathode and enter the
anode. Once in the anode, the hydrogen molecules from the fuel react with the carbonate ions and result
in products of water, carbon dioxide and two electrons per cycle. The electrons travel through the
installed wiring from the anode to the cathode to produce the generated electrical current. The produced
water and heat escape as exhaust while the carbon dioxide is recycled back with the atmospheric carbon
dioxide​ ​at​ ​the​ ​cathode.
For the process to occur, the fuel cell would need to be hot enough for the carbonate ions to form
and react in the system. Therefore, the carbonate salts that provide these ions are heated at up to 650
degrees Celsius to produce the electrolytes. Also, considering that carbon dioxide and oxygen are
provided naturally by the concentration of these molecules in the atmosphere, the only reactant considered
as fuel for the MCFC is hydrogen. Lastly, it is worth noting that this whole process would not be worth

4. fueling if it were not for the oxidation-reduction reaction that provides the desired electrical power. The
MCFC is considered a device to generate a significant amount of fuel with plenty of advantages that allow
it​ ​to​ ​be​ ​further​ ​invested​ ​as​ ​a​ ​power-generating​ ​device.
ADVANTAGES
The immense amount of research and studies done on MCFCs have proven to show great
potential in the system’s ability to produce power. One reason for our focus on this specific method of
fuel cell energy generation is its high efficiency of 65% when coupled with a turbine. This is
considerably higher when compared to phosphoric acid fuel cell plants that only maintain an efficiency of
about 37%-42%. Another advantage arises from MCFCs when a catalyst is added to the system. The
added catalyst would be installed as to convert methane and the chemical product of water into three
hydrogen atoms and carbon monoxide. The reason why the addition of a catalyst is beneficial is due to
two reasons. Reason one is that the produced carbon monoxide will expel the carbon monoxide to reduce
the likelihood of carbon monoxide “poisoning” which is a common occurrence in fuel cell operations.
Second reason focuses on the product of hydrogen out of the fuel cell which can be recycled back in as a
reactant. This allows for hydrogen to no longer be the limiting factor of the fuel cell and leaves the
responsibility of the MCFC’s life to the carbonate ions. Along with that, the catalysts that would be used
would not have to be precious metals which many other fuel cells require to utilize. Another added
advantage is the fact that MCFCs do not require a reformer to convert fuels to hydrogen as fuel as
hydrogen alone can be added to the system and still be utilized efficiently. Lastly and most importantly,
MCFCs have a superior environmental advantage by converting the atmospheric carbon dioxide to the
highly-concentrated carbon dioxide as a product. This higher-concentrated carbon dioxide can be chilled
down to a supercooled liquid state. Then, this liquid can be recycled back into the Earth’s soil, greatly
reducing the amount of carbon dioxide in the atmosphere. This system has been known to be one of the
keystone methods to decreasing the effects of climate change by physically taking carbon dioxide out of
the​ ​atmosphere​ ​while​ ​producing​ ​electrical​ ​power.
DISADVANTAGES
Molten carbonate fuel cells have few major disadvantages, and these disadvantages help to
distinguish the ideal purposes of these fuel cells rather than hinder the fuel cells use. The first
disadvantage is associated with the extremely high operating temperature. Because molten carbonate fuel
cells operate around 650 degrees Celsius there is a considerably long warm up time, as would be
expected. This really limits the mobility of the fuel cell as they can’t operate in scenarios with on-demand
power needs, or in scenarios that cannot handle the large heat. This is why molten carbonate fuel cells are
not ideal for cars, unlike the big area of research for hydrogen fuel cells. The high temperature of the fuel
cells also has corrosion associated with it. Issues are usually found with high temperature corrosion as
well as corrosive nature of the electrolytes used, but these can now be controlled to a certain degree which
helps the fuel cells reach a practical lifetime. Finally these fuel cells have a high intolerance to sulfur. The
anode cannot tolerate more than 1-5 parts per million of sulfur compounds, primarily hydrogen sulfide
and​ ​carbonyl​ ​sulfide,​ ​in​ ​the​ ​fuel​ ​gas​ ​without​ ​suffering​ ​a​ ​significant​ ​performance​ ​loss.

5. APPLICATIONS
Molten carbonate fuel cells have two major applications in the modern world. The first is power
generation and the second is as a method of CO​2 capture. One of the biggest advantages of these molten
carbonate fuel cells is that they draw CO​2 ​and oxygen from the atmosphere and create an extremely pure
product of CO​2 ​which can then be converted into liquid CO​2 ​for either storage or other potential uses.
Molten carbonate fuel cells actually rely on carbon dioxide to operate by taking it in at one electrode, that
carbon dioxide is then used to form ions that conduct current to the opposite electrode, where the carbon
dioxide is emitted. Finally, it is pumped back to the first electrode to be reused, thus forming a complete
loop. To capture the CO​2 ​the loop will be interrupted and the CO​2 ​will be taken from the exhaust of a
power plant instead of being taken from the atmosphere. After going through the fuel cell, the CO​2
,initially at about 5%-15% will go up to a concentration of about 70%; at this high of a concentration the
CO​2 ​can be supercooled into a liquid, or pressurized and pumped into an underground storage unit. This
process is type specific with molten carbonate fuel cells and does not work with any other types of fuel
cells. This process has not been applied to large scale projects yet, but the Department of Energy has
funding for the purpose of building larger systems for capturing carbon dioxide. This CO​2 ​capture is being
researched in use of large scale industrial and power practices that have large CO​2 ​byproducts. One such
industry is cement production where the decomposition of limestone by calcination creates a large amount
of CO​2 ​By utilizing these molten carbonate fuel cells, cement production can drastically reduce the
amount of CO​2 ​released into the atmosphere as a byproduct. One of the other major applications of this
effect of the molten carbonate fuel cells is in the oil industry. Current CO​2 ​is used to enhance production
at oil wells by forcing out oil that otherwise would cling to pores inside of oil reservoirs. To do this oil
companies must run pipelines in order to deliver the carbon dioxide. By utilizing molten carbonate fuel
cells, the CO​2 ​can be produced on-site. By using fuel cells to generate electricity from gases that produced
along with the oil, carbon dioxide could be produced and captured and then piped underground to free the
oil. Then excess CO​2 ​can continuously pumped underground and stored there instead of being released
into​ ​the​ ​atmosphere.
The second major application of molten carbonate fuel cells is in power generation. One of the
disadvantages of these fuel cells is that because of the extremely high operating temperature, there is a
considerable warm up period. This actually in-turn helps to determine one of the primary uses of the fuel
cells which is power generationon. The operating temperature, combined with the warm up period rules
out these fuel cells as small scale generators or engines, therefore they cannot be used in automobiles
unlike other fuel cells such as hydrogen ones. One of the first applications of these fuel cells was in the
1997 M-C Power Corporation which tested a commercial scale power generator in San Diego, California
(Figure A.)​, which utilized molten carbonate fuel cells. The test unit was installed at Marine Corps Air
Station Miramar. The fully integrated system included a stack with 250 cells, which had a capacity of 210
kilowatts with the cogeneration capability of up to 350 pounds per hour of steam which could be utilized
for heating buildings on the air station. Over 2350 hours of operation the system has a capability of 158
megawatt-hours and 346,000 pounds of steam. Since 1990 the Department of Energy has supported M-C
Power’s development of molten carbonate fuel cells through different contracts and still supports the fuel
cells to this day. This station demonstrated the ability of molten carbonate fuel cells in a commercial
cogeneration​ ​application.

6. (Figure​ ​A.)
The Molten-Carbonate Fuel Cells for Waterborne Application Project (MC WAPP) is a European
research project which is aimed at studying the application of molten carbonate fuel cell technology
on-board large vessels such as bulk carriers or cruise ships. The project uses hydrogen, obtained from a
specific system, that converts diesel oil into a hydrogen-rich gas, and air coming from the compressor of a
microturbine. The reaction produces electricity and heat without any combustion. The energy produced is
about 250 kilowatts, which is enough power for onboard system including: communications, lights, and
heating and cooling. The lack of combustion in the process means less carbon emitted into the
atmosphere, as well as less vibrations which can lead to a smoother journey. The promising nature of
molten carbonate fuel cells have caused major worldwide ship manufacturers to announce
commercialisation of this technology on fuel-cell ships in the next decade. These fuel cell ships are
currently only available in low power prototype status, but the commitment by manufacturers has
intensified the research and development. The fuel cells can provide electrical energy with much higher
efficiency​ ​than​ ​internal​ ​combustion​ ​engine​ ​vehicles.
CONCLUSION
Among fuel cells, molten carbonate fuel cells are seen as the future of fuel cell technology. They
have some of the greatest potential for positive environmental impact, while still boasting incredibly high
efficiencies in power generation. Molten carbonate fuel cells produce clean energy in a manner that
creates efficiencies ranging from 65% up to 85% when cogeneration is utilized. Their ability in CO​2
capture and assistance in CO​2 ​storage is nearly unmatched. Because of the role of carbon dioxide in the
greenhouse gas effect, this CO​2 ​capture is incredibly important. Carbon dioxide is seen as one of the
primary greenhouse gases leading to the issues that arise with climate change, such as global warming.
Because of current global politics, the role of climate change and the role of global warming, the success

7. of molten carbonate fuel cell technology, and thus the increased funding in research and development.
has​ ​never​ ​been​ ​as​ ​vitally​ ​needed​ ​and​ ​applicable​ ​as​ ​it​ ​is​ ​today.
REFERENCES
NFCRC​ ​Tutorial:​ ​Molten​ ​Carbonate​ ​Fuel​ ​Cell​ ​(MCFC),
www.nfcrc.uci.edu/3/TUTORIALS/EnergyTutorial/mcfc.html.
“Types​ ​of​ ​Fuel​ ​Cells.”​ ​Department​ ​of​ ​Energy,​ ​energy.gov/eere/fuelcells/types-fuel-cells#molten.
Types​ ​of​ ​Fuel​ ​Cells,​ ​www.esru.strath.ac.uk/EandE/Web_sites/00-01/fuel_cells/types.html.
Collecting​ ​the​ ​History​ ​of​ ​Molten​ ​Carbonate​ ​Fuel​ ​Cells,
americanhistory.si.edu/fuelcells/mc/mcfcmain.htm.
Bullis,​ ​Kevin.​ ​“Another​ ​Way​ ​Fuel​ ​Cells​ ​Could​ ​Clean​ ​Up​ ​Power.”​ ​MIT​ ​Technology​ ​Review,​ ​MIT
Technology​ ​Review,​ ​12​ ​June​ ​2013,
www.technologyreview.com/s/515026/fuel-cells-could-offer-cheap-carbon-dioxide-storage/.
Robert​ ​F.​ ​ServiceJul.​ ​16,​ ​2010​ ​,​ ​3:34​ ​PM,​ ​et​ ​al.​ ​“The​ ​Case​ ​of​ ​the​ ​Poisoned​ ​Fuel​ ​Cell.”​ ​Science​ ​|​ ​AAAS,
26​ ​July​ ​2017,​ ​www.sciencemag.org/news/2010/07/case-poisoned-fuel-cell.
Schumm,​ ​Brooke.​ ​“Fuel​ ​Cell.”​ ​Encyclopædia​ ​Britannica,​ ​Encyclopædia​ ​Britannica,​ ​Inc.,​ ​10​ ​Apr.​ ​2017,
www.britannica.com/technology/fuel-cell#ref51255.
“Molten-Carbonate​ ​Fuel​ ​Cells​ ​for​ ​Waterborne​ ​APplication​ ​-​ ​TRIMIS​ ​-​ ​European​ ​Commission.”​ ​TRIMIS,
9​ ​Nov.​ ​2012,​ ​trimis.ec.europa.eu/project/molten-carbonate-fuel-cells-waterborne-application.
Nainesh​ ​Patel,​ ​Campus​ ​Ambassador​ ​Follow.​ ​“Molten​ ​Carbonate​ ​Fuel​ ​Cell.”​ ​LinkedIn​ ​SlideShare,​ ​8​ ​May
2014,​ ​www.slideshare.net/nmpatel92/presentation1-34449623.
“A​ ​New​ ​Application​ ​of​ ​Molten​ ​Carbonate​ ​Fuel​ ​Cell​ ​(MCFC)​ ​Has​ ​Been​ ​Developed​ ​to​ ​Be​ ​Eventually​ ​Used
as​ ​an​ ​Alternative​ ​Power​ ​Supply​ ​for​ ​Ships.”​ ​Image,
www.youris.com/mobility/marine_transport/molten_carbonate_fuel_cells_an_alternative_and_cleaner_po
wer_supply_for_ships.kl.
“Application​ ​of​ ​Molten​ ​Carbonate​ ​Fuel​ ​Cells​ ​in​ ​Cement​ ​Plants​ ​for​ ​CO2​ ​Capture​ ​and​ ​Clean​ ​Power
Generation.”​ ​Energy​ ​Procedia,​ ​Elsevier,​ ​31​ ​Dec.​ ​2014,
www.sciencedirect.com/science/article/pii/S1876610214025028.