Since 9/11, people are again concerned about U.S. dependence on imported oil. It’s no secret that much of our oil comes from unstable economic or political regions of the world, and fears of political instability drive up the cost of oil. Recent government policies are encouraging both a diversity of supply and a broad mix of supply options to help lessen American dependence on imported oil.
DOE Secretary Spencer Abraham has emphasized the importance of energy supply diversity. Let’s look at some of the nation’s policy issues and some short-term alternatives to the use of petroleum.
EPAct 92 and Light-Duty Vehicle Alternatives
Early efforts included Congress’ Energy Policy Act of 1992 (EPAct 92). Its purpose was to reduce U.S. oil importation and foster U.S. energy independence through the use of alternate fuels in light-duty vehicles. Under EPAct, federal, state and local government fleets, energy providers and others were mandated to purchase ever-increasing numbers of alternative fuel vehicles (AFVs) for fuels other than petroleum.
These fuels include propane, natural gas, hydrogen, ethanol, methanol, electricity, and more recently bio and synthetic diesel.
But EPAct has had limited success, as documented in a report from the Government Services Administration (GSA).
Fleets attempting to comply with EPAct have run into a variety of roadblocks, including:
On the positive side, financial incentives—grants through Clean Cities, plus tax incentives and rebates—have worked better than EPAct mandates in advancing AFV use. The problem with EPAct is that it emphasized the purchase of alternate fuel vehicles over the use of alternate fuels. Government and private fleet managers who purchased methanol- and ethanol-burning FFVs to comply with EPAct learned that with the absence of appropriate filling stations, the vehicles would only be run on gasoline. Moreover, owners of bi-fuel CNG or propane vehicles hoping to take advantage of lower fuel prices found many of their drivers opted for gasoline out of habit, fear, or simply the closer proximity of gasoline stations.
Breaking the Stronghold – Ethanol
The aforementioned GSA report suggests that EPAct’s scope be broadened from exclusively promoting alternate fuel vehicles to include ways to use alternate fuels and ways of reducing the use of petroleum fuels.
Strategies include stricter CAFÉ requirements and financial incentives towards purchasing more fuel efficient gasoline vehicles such as hybrids.
By all projections, liquid fuel burning internal combustion gasoline and diesel engines (ICEs) will be around for years serving our nation’s needs.
High BTU content gasoline and diesel fuel powers these vehicles, but alternate motorfuels can keep these vehicles rolling with most often no modifications required. EPAct recognizes domestic renewable / sustainable fuels from cultivated energy crops, from landfill, industrial and agricultural waste, and so on. Such feedstocks are presently being used to make (liquid) alternative fuels for ICEs.
According to the Energy Information Agency, there are over 2,000,000 flexible fuel vehicles (mostly light-duty) registered for use in the U.S., yet few owners or technicians realize these vehicles can use ethanol. Through additional research and economies of scale, the cost / benefits ratio for using renewable fuels will only make them increasingly competitive with petroleum, especially as oil prices go up.
Fleets, in particular, seem poised to benefit from a quick return on investment, given their high annual fuel consumption combined with centralized refueling.
Some advocates suggest that the U.S. should make a rapid transition to high MPG hybrid-electric vehicles like those now on the market, but which can use domestically supplied ethanol made from energy crops, recycled feedstocks, etc.
According to the National Ethanol Vehicle Coalition, such vehicles have “…recently been considered by Ford, and the EPA has begun to evaluate the vehicle’s alcohol compatibility. Rollout of an E85/Electric Hybrid is expected in about five years.”
Breaking the Stronghold – Bio and Synthetic Diesel
EPAct focuses on light-duty vehicle applications. But diesel engines mostly power larger on and non-highway applications. Likewise, jet aircraft engines burn JP fuel—a derivative of diesel fuel. It is said that every minute in the U.S., 44,000 gallons are burned in diesel trucks alone, hauling products and goods to and within markets. If no other fuel does as much ‘mobile work energy’ as diesel, why not use alternative diesel fuels instead of petrodiesel to help displace imported oil? Both bio-based and synthetic fuels are compatible with petrodiesel. They may be used 100% (neat) in place of petrodiesel, or may be blended with petrodiesel. According to the National Biodiesel Board, vehicles that operate on a blend of 20% biodiesel with 80% petrodiesel (B20) will, on the average, displace more than twice as much petroleum as conventional light-duty passenger vehicles already covered under EPAct. The biofuels industry lobbied for biodiesel to be considered an alternate fuel, and in January 2001 the DOE published the final rule for use of biodiesel to fulfill EPAct requirements.
Biodiesel is renewable fuel made by chemically combining natural oils from soybeans (or cottonseeds, canola, etc.; animal fats, or even recycled cooking oil) with an alcohol such as methanol (or ethanol). Biodiesel fuels are usually more expensive than petrodiesel, but biodiesel burns with less particulate and with no sulfur or aldehydes, producing less harmful and irritating tailpipe emissions. NOx sometimes increases with biodiesel, but after-treatment devices benefit from the lack of sulfur in biodiesel. The improved lubricity and zero sulfur content of bio and syndiesel result in longer maintenance intervals, longer engine and fuel system life, and lower emissions.
Where some prefer B100, others say mixtures over 20% bring diminishing relative clean air benefits. With B100, drivers may notice a slight reduction of fuel economy and engine power compared to #2D. B20 will increase cold flow properties (cold filter clogging, pour point) by approximately 3 to 5 degrees F, but reportedly few have unusual problems when bio is blended with #1 diesel. B100 may affect (older) fuel system hoses and pump seals containing elastomer compounds.
Biodiesel tends to clean petrodiesel residues from the fuel system, so fuel filters may require frequent servicing for the first few tank fills. Reportedly, bio/petrodiesel blending standards are not finalized and more tests under various temperature conditions may be needed. “Splash blending” at the point of sale helps keep infrastructure costs down.
The DOE actively funds research to improve processes for converting domestically abundant feedstocks into alternate fuels and bring costs down. Even a small percentage of bio or synthetic diesel blended on a large scale with petrodiesel would benefit not only energy independence, but also the environment—and help the sagging farm economy.
Recognizing this, Minnesota has already passed a law requiring that petrodiesel fuel sold in the state shall include 2% bio effective in 2005.3 At least one OE suggests blending no more than 5% pending further tests, and the biodiesel industry will likely lobby for a nationwide 5% mandate. There are reportedly over 100 major fleets operating on B-20; 75 are a part of the Federal Government.
Check out the many companies on the Internet supplying bio and synthetic fuels and blends to the marketplace for ICEs. One of the more promising “gas-to-liquids” (GTL) technologies, known as Fischer-Tropsch (FT) dates back to the ’20s and WWII.
More recently, thanks to processing breakthroughs, abundant natural gas (plus coal or other feedstocks) can reportedly now be economically converted into liquid F-T fuels.7 According to University of Kansas researchers, “Preliminary engine tests indicate that these [F-T] formulations are probably the best liquid fuel that has ever been recorded for use in a diesel engine.”8 Another company reportedly has developed a different GTL process for converting natural gas into various clean fuels, using physically smaller processing facilities.
It’s not a case of whether we will be using the alternatives to petroleum as discussed above, but when and to what degree. The reasons are compelling:
energy security, the cost of importing and defending oil interests, reduction of the trade deficit, renewable/sustainable supply, domestic economic development, global warming, etc.
We as automotive technicians, educators and industry partners have the opportunity (and challenge) of adapting to these alternative technologies. The more we learn about how engineers—and policy makers—are introducing these alternative fuels into the petroleum mainstream, the better prepared we’ll be to discuss these new technologies with our family, friends, and customers.
Low Sulfur Diesel Fuel and It’s Implications
Since 1993, regulations limit sulfur content in petroleum diesel fuel for highway use to 500 parts per million (ppm) by weight.
Non-road diesel fuel sulfur ranges from 2500–5000 ppm and presently averages around 3000 ppm. We’ll see a substantial reduction of sulfur in on-road petrodiesel fuel to 15 ppm sulfur in 2006. Vehicle OEs support low sulfur diesel, stating it’s needed to make use of after treatment technologies and to pull ahead of advancing clean diesel technology. If sold here, the highly popular and fuel-efficient diesel automobiles selling in Europe could help us reduce oil consumption, but they cannot meet EPA restrictions without the use of low sulfur diesel.
Likewise, advanced technology diesel engines developed for the 80+ MPG Partnership for a New Generation of Vehicles (PNGV) rely on low-sulfur diesel, and could find their way into production autos. Unfortunately, it’s the sulfur in petrodiesel fuel that helps provide lubricity (lubricating qualities) for diesel injection system components, but removing sulfur by hydro-processing tends to reduce lubricity.
Without adequate lubricity, moving parts in the injection system will seize. Refiners are adding petroleum-based additives, but a 1–2% addition of biodiesel restores needed lubricity. SAE Standard J-2265 defines lubricity standards for diesel fuel used in North America.
Source: Rob Rodriguez (ASE)