Process Economics Program Report 243
Published: December 2001
Fuel cells are an efficient and flexible power source.
The technology is advancing rapidly for both vehicle and power applications.
Unlike conventional fossil fuel power sources, fuel cells are capable of generating
electrical power from a fuel stream and an oxidant stream without producing
substantial amounts of undesirably environmental pollutants such as sulfur oxides,
nitrogen oxides, and carbon monoxide. Most major auto manufacturers are deeply
involved in technology development, typically in partnership with fuel cell
and energy companies, and plan to launch fuel-cell powered vehicles as early
as 2002. Breakthroughs are being announced in critical need areas such as compact
and reliable fuel processors. The biggest question – and potential barrier to
widespread use of fuel cell vehicles – remains the feedstock choice. Any fuel
other than gasoline will require a new global infrastructure. Continued cost
reduction for the fuel processing as well as the fuel cell modules is the key
driver for economic viability for vehicles. Stationary power generation by fuel
cells may be somewhat ahead of vehicle use due to more attractive economics,
particularly in the niche market for moderate size power generation units.
This report has examined the current state of development
for both vehicle use and stationary power generation in small (500KW to 10MW)
fuel cell systems may soon be competitive in the distributed power market, aimed
at customers that are dependent on reliable power supply, such as hospital,
manufacturing plants and server farms.
The commercial viability of fuel cell systems will depend
on the ability to efficiently and cleanly convert conventional hydrocarbon fuel
sources to a hydrogen rich gas stream. The most advanced systems, and those
potentially closest to commercialization are based on development of gasoline
fueled polymer electrolyte membrane fuel cells for automotive applications,
and development of natural gas based solid oxide fuel cells for stationary power
generation.
Published: November 2004
With crude oil prices rising above $50/b, natural gas
prices at the U.S. Gulf Coast appear to have risen to a new floor of just under
$5/MM Btu. The demand for electric power generation appears to be driving the
demand for natural gas, with environmental concerns discouraging the use of
coal as a conventional boiler fuel. In certain regions, such concerns even appear
to be hampering the construction of long distance electrical transmission and
natural gas pipeline facilities required by large centralized power plants.
This is one factor behind the growing interest in fuel cells as an efficient,
reliable and environmentally acceptable means to small scale "distributed"
power generation.
Proven world natural gas reserves, which currently represent about 83% of the
energy equivalence of proven oil reserves, have been growing at a faster rate.
In some remote locations, wellhead costs of "stranded" natural gas
have been estimated to be below $0.25/MMBtu. New world scale methanol production
technologies using stranded natural gas as feedstock may result in the availability
of a fuel grade methanol importable to the U.S. Gulf Coast and other major consuming
regions at a price which would be competitive with that for natural gas. This
is a factor behind growing interest in methanol based fuel cell technologies
for various new small-scale mass-market transportation, portable power, and
stationary power applications.
Recent advances in liquid feed direct methanol fuel cells (DMFCs), which eliminate
the need for bulky reformer based fuel processors, may soon represent a practical
alternative to conventional batteries for laptop computers and other portable
power applications. Aside from promising considerably longer operating times
than similarly sized conventional batteries via "hot swappable" disposable
methanol fuel cartridges, DMFCs may also prove to be more economical. The scope
of this report includes a comparative evaluation of the technology, energy efficiencies
and estimated costs of DMFC concepts applied to microelectronic, portable electric
power generation, and onboard automotive electric propulsion systems. The scope
of our review also includes a rundown on the status of polymer electrolyte membrane
(PEM) development for DMFCs, including promising new membranes under development
by Polyfuel and Giner which appear to be nearing commercialization for such
mass market "personal" power applications. We also include a discussion
of a promising new sputter deposition (SD) technique which may dramatically
further reduce costly platinum electrocatalyst requirements, a major drawback
of earlier DMFC prototypes.
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