37. Do we have any air quality problems here in Minnesota?
The Twin Cities are one of 37 cities nationwide with carbon monox- ide (CO) levels which exceed federal standards. The
Clean Air Act of 1990 requires an oxygen content in all gasoline sold in the Twin Cities durig the winter months. In order
to satisfy the requirements of the program, gasoline marketers used ethanol in all gasoline in the Twin Cities area. The oxygenated
fuels program became a year round program on October 1, 199S.
38. How does the use of ethanol reduce carbon monoxide (CO)?
Since ethanol contains oxygen, it contributes to a cleaner, more efficient burn of the gasoline which results in lower
CO exhaust emis- sions. Ethanol is a simple chemical which, when burned, does not produce the complex pollutants and aromatics
formed by many hydro- carbons and gasoline additives.
39. What is an unoxygenated" fuel?
Any fuel that contains oxygen, and therefore does not need as much oxygen from the air to burn cleanly.
40. Has ethanol been successful in cleaning the air in any other cities?
Many Western and Southwestern cities have followed the lead of Denver which implemented an "oxy-fuel" mandate in 1987.
All of these cities have achieved significant reductions of carbon monoxide (CO). The winter of 1992-1993 was the first year
since 1975 that the Twin Cities did not have any CO violations!
41. Will the use of ethanol help to prevent ozone pollution?
Preliminary studies have shown that ethanol use reduces exhaust emissions which contribute to ozone. Atmospheric photoreactive
chemistry is a very complex science that is combined with computer modeling to determine which chemicals react with sunlight
to create ozone that contributes to smog formation. There is ongoing research into both the evaporative and exhaust emissions
of many components that make up reformulated gasoline.
42. What is "reformulated" gasoline?
Reformulated gasoline is a term used to describe a gasoline that results in fewer harmful exhaust emissions. The oil industry
has introduced reformulated gasolines in response to pressures from state clean air regula- tions and the Federal dean Air
Act of 1990. Reformulated gasoline, as currently produced, eliminates some of the volatile lighter elements of gasoline that
contribute to smog, plus some of the aromatics that are a known health hazard. EPA requires that reformulated gasoline shall
contain an oxygenate in all ozone and carbon monoxide non-attainment areas.
43. What is the Renewable Oxygenate Standard?
In an effort to assure that the petroleum product MTBE would not be the only oxygenate used in RFG, the U.S. EPA mandated
that 30% of all the oxygenate used in RFG shall come from renewable products. This rule not only will limit the amount of
MTBE that has to be imported from foreign countries but is a historic policy landmark that might begin to address our growing
dependence on imported energy.
44. Do diesel engines pollute more than gasoline engines?
Yes, diesel engines contribute to high particulate levels and sulfur emissions, but produce practically no carbon monoxide.
45. How does ethanol affect global warming?
Carbon dioxide (CO2) is considered a major contributor to global warming. Ethanol does not add more carbon dioxide to the
atmosphere than gasoline. Today most ethanol is made from corn, which like all plants "breathes" CO2and gives off oxygen (°2)
Therefore, increased use of renewable biomass fuels will partially offset the global warming effect of burning gasoline.
46. How long does it take for increased ethanol usage to have an impact on carbon monoxide levels?
The results are immediate, and directly proportional to the percent- age of oxygen in the fuel. The EPA has stated that
10% ethanol with an oxygen content of 3.5% will reduce CO exhaust emissions to a greater degree than 15% MTBEwith an oxygen
content of 2.7%.
47. Does an ethanol blend burn cleaner than a premium gasoline?
Many premium gasolines are ethanol blends. The fact that they contain oxygen means that it will burn cleaner than a non-ethanol
gasoline. The changes in gasoline required by the Clean Air Act will certainly clean up all gasolines in years to come, but
the addition of clean burning ethanol will likely always result in reduced exhaust emissions.