reactivity. Propane exhaust creates 60-70
percent less smog than the hydrocarbons in gasoline
exhaust, according to studies by Southwest Research
Low air toxics.
Propane cuts emissions of toxins and carcinogens like
benzene and toluene by up to 96 percent, compared to
gasoline, according to studies by Southwest Research
Ground- and surface-water safe.
Propane is nontoxic; spills vaporize rather than soaking
into soil or water.
Low greenhouse-gas emissions.
Propane has the best greenhouse-gas emissions performance
of any fossil transportation fuel when emissions from
the complete fuel cycle of production, distribution
and combustion are considered. Propane offers substantial
greenhouse benefits compared to gasoline in light-duty
vehicles and diesel fuel in heavy-duty vehicles.
An analysis by M. A. DeLucchi for Argonne National Laboratory
concluded that the LPG fuel cycle produces the least
amount of greenhouse gases of all the fossil fuel cycles,
including that of diesel fuel. The study concluded that
Liquefied petroleum gas, consisting of 95% propane
and 5% butane, offers a 20-25% reduction in emissions
of greenhouse gas from LDVs [light-duty vehicles] (compared
with gasoline). Moreover, the use of LPG in HDVs [heavy-duty
vehicles] would actually decrease greenhouse gas emissions
(compared with diesel fuel). The combined HDV-plus-LDV
effect of an LPG policy would be a better-than-15% reduction
in fuel cycle emissions of greenhouse gases.