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

� 2.5 Liquefied Petroleum Gas (LPG)
Overview
Liquefied petroleum gas (LPG), also
known as propane, can be used to
replace gasoline and diesel. LPG is the
fourth most common vehicle fuel,
behind gasoline, diesel, and natural
gas, 20 although less than two percent of
U.S. consumption of LPG is used for
transportation. 21
LPG vehicles are found
in both light- and heavy-duty
applications, such as service trucks and
buses. Like CNG vehicles, LPG vehicles
can be designed for dedicated alternative
fuel use, or for bifuel configurations
which allow for operation on gasoline as
well.
Domestic LPG sources are divided fairly
evenly between byproducts of crude-oil
refining and byproducts of natural gas
Transportation’s Role in Reducing U.S. Greenhouse Gas Emissions: Volume 2
processing. Domestic LPG demand is not high enough to justify importing oil specifically
for the purpose of creating LPG, meaning the supply of LPG is relatively constant
throughout the year. Recently, researchers at MIT have demonstrated the ability to make
“biopropane,” which is LPG made from corn or sugarcane, and have created a startup
company that is attempting to scale up the production process of LPG from corn and
sugarcane ( Bourzac, 2007). In the end however, this production method will likely only be
viable as a niche option to produce LPG given the competition for corn feedstock for
ethanol production and food and because sugarcane is not a viable large scale feedstock in
the United States.
In 2006, there were approximately 94,000 light-duty LPG vehicles in operation in the
United States, and about 70,000 medium- and heavy-duty LPG vehicles (U.S. DOE, 2007b).
The vast majority of LD LPG vehicles were converted from gasoline cars and trucks, and
no light-duty OEM models currently are available for purchase. Several OEM LPG
20 AEO 2009, Supplemental Tables 47 and 67.
21 AEO 2009, Table 2.
Liquefied Petroleum Gas
Benefits: Low:
• 17% reduction per vehicle
• Minimal market share
Net Included Costs: Not calculated
Confidence in Estimates: High
• Limited by fuel supply and inherently higher costs
Key Cobenefits and Impacts: Positive
• Potentially lower life-cycle emissions
Feasibility: High
• Existing distribution infrastructure
Key Policy Options:
• Consider incentives for niche applications such as
fleet vehicles
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