Highway Contractor

Better Roads Staff

However, he says, there is the potential for a “phenomenal return on investment. If you can latch onto a grant program, your ROI is immediate at that point – even if you have to buy a truck and spend an extra $36,000 for a CNG engine. You’ll get that payback in five to six years. And these engines are so much quieter so operators won’t have ringing in their ears. It is definitely worth it.”

Retired U.S. Army General and 2008 Presidential candidate Gen. Wesley Clark says the investment, development and use of alternative fuel technologies in all sectors of American life is more than simply a means of weaning the United States off foreign oil – it’s also the most important component for establishing a new golden age of economic prosperity that will benefit everyone.

For smaller equipment, Tews says, the industry “is just not there yet.” “We can get a gasoline van for $21,000, but to get the engine converted to CNG, that van would then cost $37,000.” Tews noted, however, that trucks the size of those that normally do the majority of snowplowing can benefit, and quickly. For example, he says, Milwaukee’s CNG refuse trucks “are just as powerful and responsive as their diesel counterparts.”

Rich Cregar, instructor/department head of Advanced Transportation Technologies at Wilson Community College in Wilson, N.C., studies the use of biodiesel.

“Fossil fuels are stable,” he says. “They have been around for 300 million years. Biodiesel is ‘unstable’ – not tried and true like fossil fuel. It’s still undergoing chemical changes.” When using fuel blends beyond B5, Cregar says, fuel quality, glycerin content, potassium content, fuel oxidation stability, water contamination, microbe growth, a high cloud point and materials interaction all need to be considered.

“You must use a high-quality filtration and water separator system, Cregar says. He suggests an extra on-board water separator that is regularly drained and maintained. “Keep the fuel as dry as you can,” he says. “Good-quality petroleum diesel has water content in the 50 ppm range. Biodiesel will retain up to 1,500 ppm of water.”

The shelf life of biodiesel is also truncated compared to its diesel alternative. “If we put 10,000 gallons of diesel fuel in a tank for six to eight months, it doesn’t matter,” Cregar says. “But biodiesel stored in an above ground tank will become acidic within a matter of months. Bio-fuel should be used within 90 to 120 days of production.”

The air space at the top of the tank should be purged with inert gas such as Argon, CO2 or nitrogen. “Don’t let it [the biodiesel] come in contact with air,” Cregar says. “Purging the air space, which removes oxygen, will improve the quality of the biodiesel.”

Cregar also warns that if biodiesel is being used in older equipment that has been retrofitted, it will attack the brass, copper, lead, tin and zinc, all of which were used in older diesel engines He also says that biodiesel can cause degradation and swelling of the elastometers, the soft parts of the system such as hoses and O-rings.

“Biodiesel will aggressively clean and scour the fuel system, including storage tanks, lines and hoses,” Cregar says. “When you convert a system that has been running on petroleum, it will initially break down any buildup. It will carry the lacquers and solids to the fuel filter, which will plug the filter. However, once the system is clean biodiesel will keep the system clean.”

Cregar says in-service vehicles converted to biodiesel in any percentage will likely require initial filter change outs, typically at least three or four. When making the conversion, though, there is no need to phase in biodiesel. “If you’re moving to B20, just go to B20,” Cregar says. “There is no need to go to B2, then B5 and on up.”

Along with biodiesel also come lube oil issues, Cregar says. “Shorten the change intervals, and establish a baseline with an initial oil analysis,” Cregar suggests.

Milwaukee’s Tews predicts it’s just a matter of time before alternative fuels become more mainstream. “In 25 years from now, when we manage to get rid of our other trucks,” Tews quips, “there may be more CNG stations.” Getting serious again, Tews says, “This is just the tip top of the iceberg with CNG. It’s coming big time.”

To promote more mainstream use, Milwaukee is encouraging the public to come to the city and buy fuel from its new CNG fuel stations. The rear of the new CNG stations is for city access only and can be accessed via radio frequency identification cards, more commonly known as RFID, or via a magnetic stripe fuel card to get the system up and running. However, both stations will be open to the public, Tews says, noting that they must be made publicly accessible because they are being built from ARRA stimulus grants. The front of the stations will be open to the public with 24/7 access, payable with a credit card.

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