U.S. EPA compares diesel cleanup options; CNG 'very expensive'

Diesel Fuel News, June 23, 2003

A new U.S. EPA comparison of options for cleaning-up diesel school buses shows that a combination of ultra-low sulfur diesel (ULSD) and a diesel particulate filter (DPF) dramatically slash particulate matter (PM) emissions while avoiding the "very expensive" cost of compressed natural gas infrastructure. The chart (below) explains the options (see:www.epa.gov/cgi-bin/epaprintonly.cgi):

U.S. Environmental Protection Agency

Clean School Bus USA

Summary of Clean Fuel / Clean Technology Options

This chart summarizes the benefits, costs and applicability of various
technologies discussed in the Retrofit and Replacement Clean School Bus
pages.

Clean Fuel/Clean Technology Options  Type of Engine


Ultra-Low Sulfur Diesel (ULSD)       New or Used Diesel Engine







Particulate Matter Filter            New or Used Diesel Engine-1995 or
                                     newer models


Oxidation Catalyst                   New or Used Diesel Engine


Compressed Natural Gas (with an      New CNG Engines
oxidation catalyst)






Biodiesel Fuel                       New or Used Diesel Engine

B20: 20% biodiesel, 80%
regular diesel

B100: 100% biodiesel


Emulsified Diesel Fuel               New or Used Diesel Engine


Clean Fuel/Clean Technology Options  Percent Reduction in Emissions of
                                     Particulate Matter

Ultra-Low Sulfur Diesel (ULSD)       About 5 to 9%

                                     Enables the PM filter technology
                                     to work




Particulate Matter Filter            60 to 90%



Oxidation Catalyst                   20 to 30%


Compressed Natural Gas (with an      70 to 90% if using catalyst
oxidation catalyst)                  technology to reduce ultra fine PM,
                                     formaldehyde, and methane -
                                     otherwise, methane and aldehydes
                                     will be much higher than diesel
                                     engines


Biodiesel Fuel

B20: 20% biodiesel, 80%              B20 - 10%
regular diesel

B100: 100% biodiesel                 B100 - 10%


Emulsified Diesel Fuel               About 50%


Clean Fuel/Clean Technology Options  Percent Reduction in Emissions of
                                     Nitrogen Oxides

Ultra-Low Sulfur Diesel (ULSD)       N/A







Particulate Matter Filter            N/A



Oxidation Catalyst                   N/A


Compressed Natural Gas (with an      About 60% reduction but are highly
oxidation catalyst)                  variable (sometimes increases
                                     occur)





Biodiesel Fuel                       Biodiesel increases emissions of
                                     Nox slightly.
B20: 20% biodiesel, 80%
regular diesel                       B20 blend +2%

B100: 100% biodiesel                 B100 fuel +10%


Emulsified Diesel Fuel               About 10%


Clean Fuel/Clean Technology Options  Approximate Cost of Technology


Ultra-Low Sulfur Diesel (ULSD)       8 to 25 cents per gallon more than
                                     regular diesel now


                                     In June 2006, when ULSD will be
                                     required nationwide, cost
                                     differential will be much less

Particulate Matter Filter            $5,000 to $10,000

                                     Must used ULSD fuel

Oxidation Catalyst                   $1,000 to $2,000 and can be used
                                     with regular diesel

Compressed Natural Gas (with an      $30,000 more than a diesel bus
oxidation catalyst)                  (cost of CNG fuel similar to
                                     regular diesel fuel)

                                     Very expensive special re-fueling
                                     infrastructure and maintenance
                                     facilities are required

Biodiesel Fuel                       B20 - 15 to 30 cents per gallon
                                     more than regular diesel
B20: 20% biodiesel, 80%
regular diesel                       B100 - 75 cents to $1.50 per gallon
                                     more than regular diesel (B100 may
                                     not be an option for cold
                                     climates)

B100: 100% biodiesel                 (B100 may not be an option for cold
                                     climates)

Emulsified Diesel Fuel               20 cents per gallon more than
                                     regular diesel fuel