Transportation's Role in Reducing U.S. Greenhouse Gas Emissions ...

Development of a Hydrogen Infrastructure
Transportation’s Role in Reducing U.S. Greenhouse Gas Emissions: Volume 2
Development of a hydrogen production and distribution infrastructure is a critical challenge in
the transition to widespread use of hydrogen as a transportation fuel. There are several options
for producing hydrogen for FCVs. One option is to generate the hydrogen at a central
production facility, such as a plant which performs natural gas steam reforming, then transport
the hydrogen to a distribution network for transfer to refueling facilities. This requires
development of a new fuel distribution network. Delivery and dispensing of hydrogen could
cost as much as its production and consume significant energy, thereby negating much of the
GHG reduction potential (Jones, 2008).
In Jones’ aggressive FCV deployment scenario, it was assumed that initially excess hydrogen
from current industry production would be trucked to a few select stations, or stations would
house small natural-gas reformers. As consumption and geographic coverage increases,
increased production volumes would be accomplished via large appliance-type hydrogen
production units fueled with natural gas or renewable liquid fuels such as ethanol. In the later
transition stage, production would be accomplished at large central production plants using
primary feedstock such as natural gas, coal with CO2 sequestered, and biomass.
Two delivery technologies are feasible for hydrogen produced at centralized locations—
pipelines and tanker truck (U.S. DOE and U.S. DOT, 2006). The existing hydrogen pipeline
system is only one-third of 1 percent of the natural gas network length (EIA, 2008). Therefore in
the short term, long-distance transport of hydrogen via tanker truck is the most likely delivery
option. Most hydrogen will need to be transported in liquid form due to the increase in energy
density compared to gas. There are currently seven liquid hydrogen plants in the U.S. supplying
760 million gge per day (EIA, 2008).
In the short-term distributed natural gas and on-site electrolysis are advantageous for the
transition to hydrogen FCVs because they avoid the need for a new delivery infrastructure. Both
small reformers and water electrolysis systems can be built in a modular fashion (i.e., sized for
demand) for placement at existing gasoline stations (Jones, 2008). The components at the
hydrogen fueling stations would be similar regardless of whether hydrogen is produced on site
or at a centralized location. These facilities will require hydrogen storage, compression, and fast
delivery systems.
DOE also envisions a transitional approach relying on a distributed fueling infrastructure in
high population density areas, such as Southern California and New York City, with expansion
to Boston and Washington, D.C. in future years. This distributed approach is less capital
intensive, depending on steam reformation of natural gas as the primary source of hydrogen
through the mid-term (GAO, 2008). However, for hydrogen to become a widespread
transportation fuel, economics will require its production at centralized facilities delivered via a
pipeline infrastructure (GAO, 2008).
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