Cleaner fuels help clean air in Minnesota

Gasoline: First the lead, now the sulfur

Not since lead was taken out of gasoline in the 1970s, have so many environmental improvements been made to vehicle fuels. At the start of 2004, low-sulfur gasoline was mandated to be phased in by 2006 in the United States. But a few companies (Holiday in all grades and Amoco in premium) have offered low-sulfur fuel in the metro area since 2001.

Sulfur in U.S. gasoline had been averaging about 300 parts per million (ppm) but the new low-sulfur fuel has only 15 ppm.

• Sulfur in fuel creates fine particulate matter (PM) or airborne soot—microscopic particles that cause heart and lung problems.
• Using gasoline with just 15 ppm sulfur, along with new catalytic converters (starting with the 2004 model year), reduces smog-forming emissions by up to 95 percent.

What about diesel fuel?

Diesel fuel is a multi-purpose petroleum fuel used in trucks, trains, boats, buses, planes, heavy machinery and off-road vehicles. It also remains one of the largest sources of fine particle air pollution, which has serious health impacts. Besides fine particles or soot, Diesel-fueled engines also emit nitrogen oxides that can form ground level ozone (“smog”).

Another cleaner fuel choice – Ultra low sulfur diesel fuel

The good news is that ultra low sulfur diesel (ULSD) fuel was phased in throughout the U.S. during 2007.  Sulfur content had averaged between 300-500 ppm but the new ULSD has just 15 ppm.  This is cleaner than Europe’s diesel which has sulfur levels of 50 ppm.

When the new fuel is coupled with newer clean diesel engines (phased in from 2006) with diesel oxidation catalysts — particulate emissions are reduced by about 90 percent.

Reducing the sulfur will make a very significant improvement to air quality by reducing the fine particles so prevalent in diesel exhaust.

• Way ahead of schedule — Metropolitan Council, with help from the MPCA and the Department of Commerce, contracted to purchase about four million gallons of ultra low sulfur diesel (ULSD) fuel in the summer of 2004.
• New clean diesel engine technology became standard on all new highway diesel engines manufactured after 2006 and maximizes emission reductions when combined with ULSD.
• In 2007, sulfur was reduced to just 15 ppm for highway vehicles. When used in vehicles with new diesel technology, the health benefits are significant and point to a brighter future as older diesel vehicles die out or are retrofitted.

Minnesota is first state to mandate biodiesel blend

Thanks to legislation passed in 2003, Minnesota was the first state to mandate a biodiesel blend of diesel fuel for highway vehicles.  Since July, 2005 all highway diesel fuel in Minnesota contained two-percent biodiesel.

In May 2009, Minnesota will increase it’s biodiesel blend to five-percent. Biodiesel fuel has less sulfur and less hydrocarbons and like ethanol products, reduces dependence on foreign petroleum. Biodiesel is made from vegetable oils or animal fats. For more information, visit the Minnesota Soybean Growers Association Web site.

Five-percent biodiesel will make about a five-percent reduction in fine particles and hydrochanges. It’s a good start. This mandate increases to 10-percent biodiesel (B10) by May 1, 2012 and 20-percent biodiesel (B20) by May 1, 2015. Blends above 5-percent only apply during warm-weather months (April – October). Some co-ops already sell B-20 diesel fuel that is 20-percent biodiesel. Several cities and counties in Minnesota have been using B-2 to B-20 for years in buses, trucks and snowplows.

For more information, see the Diesel Retrofit Web page which also shows a list of counties using biodiesel blends greater than two-percent in their fleets.

Future fuels

There are a number of types of fuels currently being developed for future use in transportation.  The next generation of biofuels are expected come from cellulosic sources--the non-edible parts of plants, including agricultural waste, wood, and grasses.   Even algae, which grows rapidly with minimal demands on space or location, while yielding a high level of oil - oil that can be used to produce biodiesel.  

Hydrogen derived from water can be used in fuel cell vehicles.  When wind or solar generated electricity is used to split the water there is no pollution emitted either during its production or during use of hydrogen in a fuel cell vehicle (only water and a small amount of heat are generated by fuel cells).

Renewable electricity generated from solar panels or wind generators can be used to directly charge the batteries of electric vehicles.

Research related to these potential fuels continues, inspired by the promise of emitting less or zero air pollution and the opportunities for local energy generation.

New clean diesel technology

• New clean diesel engine technology became standard on all new highway diesel engines manufactured after 2006 and maximizes emission reductions when combined with ULSD. Emissions are reduced 90-percent when compared to pre-older engines (without retrofit technology) using non-ULSD diesel fuel.
• Diesel owners can retrofit their older vehicles with these new devices. For more information see the following:
  • Cleaning up diesel engines in Minnesota
  • Emissions from the Bus Go Down, Down, Down article in Minnesota Environment 2005 Winter (me-winter2005)

Cleaning up older diesel engines

The Minnesota Pollution Control Agency (MPCA) is focusing its efforts in partnerships with diesel fleet operators, both public and private, to reduce diesel air pollution through the use of cleaner fuels and new technologies that can be added or “retrofit” to existing diesel engines.

The MPCA is a major partner of Clean Air Minnesota’s Project Green Fleet since it began in 2005. The project has made arrangements to have a total of more than 1,000 diesel school buses in Minnesota retrofitted with diesel oxidation catalysts and crankcase ventilation filters by the end of 2008. These improvements reduce fine particulate emissions by about 30 percent. Diesel truck fleets can also benefit from Project Green Fleet. See the Project Green Fleet website for more information.

Information about diesel exhaust and your health is available in the following fact sheet:

• Diesel Exhaust in Minnesota, What are the Health Effects, Who's at Risk and What Can You Do? (aq-mvp2-25)

What's the cost of diesel retrofit technology?

The health benefits far outweigh the cost. In fact, the U.S. Environmental Protection Agency (EPA) estimates that for every dollar spent on cleaner diesel fuel and cleaner engines, there is a seventeen dollar benefit – mostly from reducing premature deaths and some reduced health care costs associated with respiratory illnesses. Reference: Regulatory Impact Analysis (EPA420-R-00-026).

A typical DOC retrofit is about $2,000 including installation and will reduce emissions by 30%. Averaged over 10 years, that’s $200 per year.

More information and assistance

For more information about cleaner fuels, contact Fran Crotty at 651-757-2297 or Mark Sulzbach at 651-757-2770.