POWER May 2017 - 24

DISTRIBUTED GENERATION
The Long History of Fuel Cells
Fuel cells have a history going back more
than 200 years. Groundbreaking early
19th-century British chemist Sir Humphry
Davy-who also isolated the elements
calcium, strontium, barium, magnesium,
and boron in 1807 and 1808-posited
the electrochemical principle behind fuel
cells in 1801. He reasoned that it would
be possible to reverse the splitting of water
into hydrogen and oxygen, generating
a current. British chemist, physicist, and
lawyer William Grove generally gets credit
for the first fuel cell, in 1839, which he
called a " gas voltaic battery. "
Grove showed that a reaction between
hydrogen and oxygen with a platinum catalyst
could produce a current. At the time,
it was simply an interesting phenomenon
with unknown practical applications.
In 1889, Charles Langer and Ludwig
Mond coined the term " fuel cell " as they
tried unsuccessfully to make a practical
device using air and coal gas. Many other
researchers also tried to use fuel cells to
convert coal directly into electricity, but
that was a dead end.
In 1932, Francis Bacon, an engineering
professor at Cambridge in England, invented
a rudimentary fuel cell, but it took
him until 1959 to demonstrate a working,
5-kW design. At about the same time,
American Harry Karl Ihrig rolled out a fuel
cell-powered farm tractor that was modified
to use a 15-kW (20-hp) unit. The U.S.
Air Force, working with Allis-Chalmers,
soon developed fuel-cell vehicles, including
a forklift and a golf cart.
The
simple,
emissions-free
technology
proved a good fit for certain highly
specialized applications like space travel.
NASA in the late 1950s and 1960s used
fuel cells for its manned space missions,
refining proton-exchange membrane
technology using platinum as a catalyst,
which they used in the Gemini program.
A Pratt-Whitney subsidiary, later acquired
by United Technologies Corp., developed
a 1.5-kW fuel cell for use in the Apollo
program (Figure 3) and the space shuttle,
up to 90% of the incoming CO2, which flows
with the CO2 generated in the reforming process
into the normal exhaust stream, where it
can easily be separated from the water vapor.
According to FCE, the power output is larger
24
3. Space power. Each Apollo spacecraft
carried three fuel cells like this one.
They generated electricity for the spacecraft
by combining hydrogen and oxygen. A
by-product of the reaction was water, which
the crew could drink. Courtesy: Creative
Commons/James Humphreys
gather data for the development of a largescale
test using flue gas from both coal and
natural gas exhaust streams. The Department
of Energy, which has already been supporting
FCE's research into coal-plant CCS, is
also a partner in the project. That announcement
drew additional attention, with other
companies in the U.S. and Canada reaching
out to FCE about possible CCS applications,
not just in power generation but additional
fields such as oil and gas processing, cement
manufacturing, and steel mills.
According to Tony Leo, FCE's vice president
of applications and advanced technologies
who spoke to POWER in March, FCE
and ExxonMobil will be working on the initial
testing and engineering for the next nine
to 12 months, with an aim of beginning construction
in 2018 and starting up in late 2018
or 2019. Leo said the approach does not vary
that much whether coal or natural gas flue
gas is used.
" Because there is so much cleanup of the
providing electricity and drinking water
for the crews.
These early designs worked well enough,
but they were far too expensive for general
use. It took the Arab oil embargo and
the subsequent dramatic increase in oil
prices during the 1970s to spur new fuel
cell ventures. Many of these were aimed
at transportation, and automakers worldwide
experimented with fuel-cell electric
vehicles. Developments around molten
carbonate fuel cells in the 1970s and
1980s, funded by government and electric
utilities, raised the prospect of reforming
natural gas for hydrogen to power large
stationary power plants.
By the turn of the century, the prospect
of utility-scale fuel cells had largely faded
and attention turned to smaller systems,
for transportation applications and for
distributed power on the customer side of
the electric meter. Those two applications
continue to dominate, but neither has yet
resulted in fuel cells becoming anything
other than niche players.
than the parasitic drain from previous CCS
technologies.
In October, FCE and ExxonMobil announced
that they were deploying a pilot test
at Southern Co.'s Plant Barry in Alabama to
www.powermag.com
flue gas in a modern coal plant, the primary
differences are just that the coal flue gas is
at ambient temperature but has a higher CO2
concentration, which make it easier to capture, "
he said. " But because our fuel cell is
a high-temperature system, the hotter flue
gas from a gas turbine means we can capture
thermal energy from it. So there are pluses
and minuses for both. "
ExxonMobil has not been shy about their
enthusiasm for the partnership. Vijay Swarup,
vice president for research and development,
called the technology a " game changer "
for CCS when it was first announced. As a
sign of how seriously the company is taking
things, new CEO Darren Woods called
out the project as one of his priorities for the
company's future in a February 23 blog post.
" ExxonMobil is investing heavily in CCS,
including research in a novel technology that
uses fuel cells that could make CCS more affordable
and expand its use. "
A Path to Profits?
Fuel cells remain a relatively expensive
means of generating power, and repeated
stumbles by some fuel-cell companies make
it clear the sector is still in search of a profitable
niche. Could it be CCS? Thus far, no
other CCS technology comes close to offering
what fuel cells could, with all other approaches
being parasitic drains-sometimes
very large ones-on generation. If FCE and
ExxonMobil can make it work cost-effectively,
CCS could be the " killer app " fuel cells
have been seeking for decades. ■
-Thomas W. Overton, JD is a POWER
associate editor and Kennedy Maize is a
long-time energy journalist and frequent
contributor to POWER.
POWER | May 2017
http://www.powermag.com
POWER May 2017

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