Turning Field Crops into Fuel Gold

Stories are that farmers across the country are tearing out their old crops and planting corn as quickly as they can to answer the anticipated demand for an alternate fuel, ethanol. States are offering subsidies for those who will build conversion plants to turn the corn into ethanol. While the fuel may work for gasoline-powered passenger vehicles, it doesn't work all that well in larger engines for trucks that presently require diesel fuel.

"Corn oil would make a stock for biodiesel," claims Tom Verry, director of Outreach and Development, National Biodiesel Board (NBB-www.biodiesel.org), "but corn contains less than 5% oil and soybeans are about 20%." Many members of the NBB are soybean growers. As Verry explains soybean farmers have put $60 million into the NBB since it was created 15 years ago. They did so because soybean oil has been a huge surplus over the years in the United States. It was grown as the least expensive way to provide protein for animals.

About half of the beans are exported. "Over 80% of the vegetable market in the U.S. is soy," notes Verry. "There are billions of pounds of soybean oil sitting on the market every year. The farmers looked for a way to use the surplus." Biodiesel has offered an answer.

As the NBB explains, biodiesel is made through a chemical process called transesterification that separates glycerin from fat or vegetable oil. The glycerin is sold to be used for production of soap or other commodities, and the remaining product is methly esters, the chemical name for biodiesel.

Verry points out that biodiesel can be blended with petroleum diesel and put to work in compression-ignition (diesel) engines with little or no modification. "You can use biodiesel in any blend of diesel with no modification to your engine, up to 100% if you like," he says. "However, almost all biodiesel used is blended with diesel anywhere from 5% to 20%, with 5% being the most common blend for trucks."

The NBB claims that biodiesel is now available in all 50 states and more than 2,000 petroleum distributors carry it. "We see biodiesel having the same power and performance as straight diesel," claims Verry. "Biodiesel does have a few less btu's than straight diesel. On a 5% (B5) blend it's not that noticeable. Even at 20% (B20) it's not statistically significant. On a 20% blend, you might see a 2% drop in performance." However, the NBB says that anecdotal evidence is that truckers are really sold on it. The drivers like the idea that it's helping American farmers and reducing dependence on imported oil. They think they get better mileage. Verry notes that biodiesel, even at 5%, will maximize the lubricity benefit for the engine, so it will run smoother, quieter and cooler.

Lower emissions are another benefit of using biodiesel. "There are some benefits at B5," explains Vrerry, "but obviously not very much. At B20, you get 12%18% reduction in carbon monoxide, particulate emissions and volatile organic compounds."

For now, biodiesel pricing at the pump is fairly competitive with straight diesel. A major reason is there is a $1 a gallon federal fuel tax incentive to encourage production. Support is coming as well from some states that are adding similar incentives for the use of biodiesel.

Verry points out that, "New York, Texas and Illinois have substantial tax incentives for biodiesel users. That really makes biodiesel competitive with or below the cost of diesel." Texas is the biggest diesel state in the country, and it has reduced the state excise tax on the fuel. Illinois reduced the sales tax and New York reduced three state taxes."

Biodiesel producers are not alone in the search for alternative fuels for powering larger truck motors. One major engine manufacturer has been very active in research into engine fuels. "Right now we are fully comfortable with B5 and we are working on B20 although we have some concerns with that," explains Tony Grezler, vice president of Advanced Engineering, Volvo Powertrain North America (www.volvo.com). "But certainly it's a very viable fuel and one we intend to promote and work with."

Key criteria applied to the research is the efficiency of a fuel from well to wheel—every bit of energy that has to go in from making the fuel to the efficiency of the vehicle. The manufacturer has a great concern as well with the greenhouse gas impact of utilization of a given fuel. Grezler classifies three different types of fuel Volvo is looking at. The first is biodiesel made from vegetable oils or animal fats—the fatty acid methly esters.

The second types are synthetic diesels. "These are basically very clean diesel fuel that's synthesized either from biomass,, coal or gas," notes Grezler. We call them BTL (Bio to Liquid), CTL (Coal to Liquid) and GTL (Gas to Liquid). Those all come out of a synthesized process that results in the same product for all sources, a long chain of pure hydrocarbon that burns relatively cleanly and provides good diesel properties."

The third class is what Volvo characterizes as fuels not fundamentally compatible with diesel. Those that would require a different infrastructure, engine, or fuel system. "These are things like natural gas, Dimethlyether and ethanol to some extent," says Grezler. "We are looking at that as a possible fuel. Actually you can mix up to about 15% ethanol with diesel and still use it in a diesel cycle. So it is possible, although there are some drawbacks."

Looking at the short term, Grezler sees focus remaining on biodiesel for the next five years or so. Then he thinks most likely there will be introduction of synthetic diesel, whether from coal, natural gas, or biomass. He feels that from the viewpoint of greenhouse impact, biomass is the best choice, while with the aim being reduction in the use of petroleum, coal offers a good synthetic fuel option.

Great effort is being made by many to find a sustainable fuel that not only lessens dependence on fossil fuel, but helps clean the air as well.

The United States Postal Service (USPS-www.usps.com) has the country's largest number of alternative fuel vehicles in its fleet. It is using the fleet to evaluate a number of alternate fuels, including biodiesel, ethanol, and compressed natural gas, as well as examining electric vehicles.

The USPS is also delivering the mail three days each week in a minivan powered by hydrogen fuel cells. Hydrogen fuel cell-powered vehicles emit only water and are greatly more efficient than internal combustion engines. The problem, of course, comes in securing needed hydrogen to power the cells.

While the testing and analyzing of the General Motors HydroGen3 minivan has been in the Washington, D.C. area, the USPS is expanding testing by putting an additional vehicle into service in the Irvine, CA mail delivery fleet.

Having recently introduced four hybrid electric medium-duty trucks into service in greater Denver, FedEx Express (www.fedex.com) now has 93 such vehicles in operation in cities like Tampa, Sacramento, New York City and Washington, DC. The FedEx hybrid has been developed in cooperation with Eaton Corp. and Environmental Defense (www.environmentaldefense.org).

The hybrids are part of an alliance that FedEx Express and Environmental Defense began in 2000. Advantages claimed for the vehicles include reductions in soot by 96% and smog by 65%. Operating costs are cut by a full third, with the vehicles able to travel 57% farther on a gallon of fuel.

Carriers looking at alternate-fuel vehicles
UPS (www.ups.com) has added 50 hybrid electric vehicles (HEVs) to its delivery activities in Atlanta, Houston and Phoenix. The expedited/express carrier expects the new HEVs will reduce fuel consumption by 44,000 gallons a year when compared to traditional diesel trucks. They should also reduce the amount of carbon dioxide (CO2) exhausted by 457 metric tons.

The new fleet is made up of two different van sizes manufactured by Workhorse Custom Chassis and Freightliner LLC. Both will use a hybrid power system from Eaton Corp. (www.eaton.com).

The power system permits the use of a smaller diesel engine than in a conventional delivery vehicle. A battery pack using lithium ion batteries, a motor/ generator and power control system are the other components. UPS will share its results on fuel economy, emissions and other performance data with the US Department of Energy.

Renewable diesel fuel
Processing technology for converting animal fat into renewable diesel was tested successfully last year by a crossfunctional team at the ConocoPhillips (www.conocophillips.com) Whitegate refinery in Cork, Ireland. One result is a joint effort by the energy company and Tyson Foods, Inc. (www.tyson.com) to use beef, pork, and poultry by-product fat to create what they term renewable diesel.

Advantages of the fuel claimed by ConocoPhillips are that once produced it is chemically equivalent to conventional diesel and can be shipped and distributed through existing infrastructure. The company says the fuel has improved lubricity and a higher cetane--the equivalent concept of octane for gasoline-than conventional diesel.

Cleaner burning than conventional diesel, renewable diesel produces less nitrous oxide and has ultra-low sulfur content. Renewable diesel and biodiesel both use similar stock but are processed differently and result in chemically different products.

For its part, Tyson created a Renewable Energy group last year to explore ways in which it could use its supply of animal fat into biofuel, among other energy projects in which it is engaged.

Alternative Fuels
Volvo has been studying in great detail a number of alternative fuels with an eye toward uncovering those that could be produced on a large scale, have limited environmental impact and deliver high efficiency through the well-to-wheel chain. This chart indicates the well-to-wheel performance of each fuel, along with its energy efficiency and emission of greenhouse gases.

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