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 — the 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 in the U.S. 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 at least a two-percent biodiesel blend.
In May 2009, Minnesota increased its 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 in Minnesota and helps the Minnesota economy. It is usually produced from vegetable oils such as soybean oil. For more information, visit Minnesota Soybean Growers Association.
This state mandate increased to 10-percent biodiesel (B10) in April 2014. Ten-percent biodiesel will make about a 10-percent reduction in fine particles and hydrocarbons. It’s a good start. Twenty-percent biodiesel (B20) is scheduled to begin by May 1, 2018.
Note that all blends above 5-percent only apply during warm-weather months (April – October). Some co-ops have sold B-20 diesel fuel since the year 2000. Several cities and counties in Minnesota have been using B-2 to B-20 for a decade in buses, trucks and snowplows.
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.
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.
- Project Green Fleet
- Diesel Exhaust in Minnesota, What are the Health Effects, Who's at Risk and What Can You Do?
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.
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.