NGV America – Sunday, November 01, 2015
On Friday, the U.S. Environmental Protection Agency (EPA) finalized a
new national standard for ozone air quality. The move could pave the
way for more natural gas vehicles. The new standard requires that
average ozone levels be no more than 70 parts per billion, an increase
in stringency from the current standard of 75 parts per billion
established in 2008.
Ozone, or smog as it is sometimes called, “causes a number of harmful
effects on the respiratory system, including difficulty breathing and
inflammation of the airways.” Ozone alert days most often occur during
the summer months when temperatures are high and there is lots of
sunlight. A key contributor to ozone is nitrogen oxide (NOx), which is
created in the combustion process in engines. Natural gas engines offer
superior benefits with the lowest NOx emissions among transportation
fuels used today in high fuel use, medium- and heavy-duty trucking.
Cummins Westport Inc. (CWI) has received recent accolades after
receiving CARB certification for an 8.9-liter natural gas engine that
was certified to the cleanest standard available for NOx (0.02 g/bhp-hr)
and demonstrated actual emissions far below even this level. These
engines will enter the market in 2016.
As required by the Clean Air Act, EPA anticipates making
attainment/nonattainment designations for the revised standards by late
2017; those designations likely will be based on 2014–2016 air quality
data. For more information on the designations schedule and the rule,
visit the EPA website.
This article was first published