Clean Diesel Systems: More Than Just Fuel

EPA's approach to clean diesel systems is driven by regulations but facilitated through funding incentives that encourage new technology development and voluntary participation
(Graphic: B. Chabot. Graphic source: Diesel Technology Forum) The holistic approach of EPA is powering the transition to a clean diesel system that goes beyond just setting regulations and then expecting compliance. It resulted in increased buy-in, and with that a more effective effort from all affected groups. More than setting goals, the promotion of voluntary efforts from industry and other stakeholders - facilitated by genuine discussions, funding programs to help defray the costs of developing and implementing technologies and monitoring the progress, as well as granting extensions when good-faith efforts need just a little more time - resulted in the realization of the opportunity to reduce foreign oil consumption, achieve higher fuel economy and lower emissions.  Cheryl Newton, an EPA regional deputy director, said, "Our air is getting cleaner while our standards are getting tougher." The process is about working collaboratively with individuals, companies, industries and local governments to address solutions that are meaningful and workable. The Agency's belief is that the "carrot" leads to more buy-in than the "stick," which is better reserved for those chronic offenders who resist beyond reason. Change is in the air While the efficiencies of diesel have long been recognized, there have been a number of drawbacks. High soot levels which can aggravate pre-existing health conditions such as asthma, as well as high emissions of dangerous nitrous oxide (NOx), carbon monoxide (CO), sulphur dioxide (SO2), hydrocarbons (HC) and fine particulate matter (PM) polluted the public's image of diesel.  That's about to change. The new EPA standards will see, by 2010, a 60 percent drop in NOx and 70 percent drop in SO2 levels, compared to those in 2003. In addition, reductions in PM, HC, CO and other emissions will be realized. While much of this will be enabled by the introduction of ultralow sulfur diesel (ULSD), which will increase the cost of diesel fuel by eight cents per gallon, the solution isn't just in using cleaner fuel. It wasn't that long ago that diesel had a high sulfur content of 3,400 parts per million (ppm). Over the last decade, the move to low sulfur diesel saw the level fall to 500 ppm. Bob Schaefer, BP's regulatory issues manager explained that the imminent advent of ULSD will see sulfur levels of diesel fuel fall to a maximum of 15 ppm, from refinery through to retail outlet. As of June 1, 2006, 80 percent of diesel fuel produced at refineries must be ULSD. This requirement will flow downstream, with a Sept. 1, 2006 deadline for distribution terminals and an Oct. 15, 2006 deadline for all retail outlets. Developing a clean diesel system is more than just making cleaner fuel. Advanced engine and emission technologies can be leveraged off of cleaner diesel fuel and pay dividends as well. Improved electronic combustion control, fuel injection systems and turbochargers are just some of the technologies employed in current and future diesel engines. Likewise, innovations in diesel emissions control add efficiency. Particulate filters and traps, oxidation catalysts, engine gas recirculation, selective catalyst reduction and others capture more fine particles and reduce the emission levels of NOx, SO2 and other compounds.  During the seminar, the amount of innovation implemented in pilot projects and real-world applications was highlighted. OEMs worked with end-users, developing and proving technologies in the field. Public works projects, such as the current expansion of O'Hare International Airport, demonstrated the impact of using ULSD and emission reducing retrofits to construction equipment and trucks. Ken Katch, director of Caterpillar Inc.'s Emission Solution Group commended the EPA's approach: "Incentive programs are needed to move the tipping point for voluntary program participation." He said that while Caterpillar had spent in excess of $1 billion in research and development for clean diesel, much of it was in collaboration with other companies. Other company and government representatives echoed this theme, saying that cooperation allowed funding to be focused and spent in a synergistic fashion with better and faster results, with less waste and duplication, than what would have occurred, had participants worked alone.Legacy diesel engines need to be invited to the dance New cars, such as Mercedes-Benz' Bluetec diesels that will be introduced into the United States this summer, have the technology advances to capitalize on ULSD. Likewise, many of the other new cars and trucks to be introduced in the future also will benefit. But what about the more than 11 million diesel engines on roads today? With diesel engines lasting longer than gasoline-powered ones, the longer life provides the opportunity to refit older diesel engines and enough time to recover costs in many cases. According to EPA, there are a number of means to address older diesel engines that can improve their emission levels and other efficiencies. The Agency has grouped these into what it calls the Five R's:* Refuel - Older diesel engines can run on newly formulated fuels, such as ULSD and biodiesel, which is primarily derived from soybean oil.* Retrofit - Incorporating modern diesel oxidation catalysts and particulate filters will reduce emissions, even from older engines. Installing crankcase emission controls will also help.* Rebuild - When repairing older diesel engines, consider upgrading where possible to more modern equipment.* Repower - Employing a modern diesel engine may be the best alternative in some cases. * Replace - If there is no other cost-effective solution above, vehicle replacement may be required. Besides modern diesel engines, other alternatives to consider include hybrid-electric, hybrid-hydraulic and natural gas. Tom Pelletier, the fleet maintenance manager for the Naperville (IL) School District shared his experience in a project involving the help of BP, International Truck and Engine Corp. and EPA. Pelletier recognized that there would be a natural resistance to change had his staff known in advance of the project. Without his staff knowing, a number of school buses were retrofitted by International. BP supplied the ULSD, and EPA helped in verifying test results.  Since the beginning of the school year, compared to the rest of the school bus fleet, the test group's engines have burned fuel cleaner, emissions have been reduced to comply with the new regulations and the riders on those buses who have asthma or other conditions have breathed easier, without the coughing, sneezing and breathing problems prevalent on unmodified buses. " You've got to be able to touch it and feel it to understand it," Pelletier told the audience.Thinking out of the box In the rush to clean diesel and related technologies, the effects of conservation are sometimes passed by. Yet with some perceptive thinking, there are means of reducing the use of diesel (and thereby foreign oil dependency) and emissions that don't involve changes to engines as noted above. Encouraging more efficient usage of diesel with reduced emissions through the trading of energy "cap and trade" system is one way. Reducing waste by idle reduction is another. Already established in the European Union and in Canada, the use of a market trading mechanism has led to more efficiency and lower emissions. For diesel users, a cap value on emissions is given that varies by type of user. A third-party organization such as EPA would verify results. Those users who come in under the cap value would earn energy credits. Those whose results are above their assigned cap would have to buy credits from those users holding earned credits. The incentive to improve is the cash received from selling credits, which can then offset the costs incurred to make improvements. 

On-Board Electric Truck Idle Reduction System
(Photo: California Department of Energy/Sacramento Municipal Utility District) Ed Arts, a director with EcoTrans Technologies noted that the cap and trade system in Canada had helped CN Railway to reduce NOx, CO and HC emissions by more than 90 percent and PM emissions by 84 percent. The cost-effective reductions were realized by using auxiliary electric power units (APUs) on locomotives. Instead of having them idle for between six and eight hours per day, the APU's allowed locomotives to be shut down. This technology is transferable to heavy-duty diesel engines. The quest of savings from idle reduction has also led to an innovative solution in the trucking industry, known as "truck stop electrification" (TSE). Drivers are required to rest eight hours for every 10 hours of driving. Historically, drivers idle their engines about eight hours a day or as much as 1,800 hours annually to power A/C and sleeping cab comforts. Idling also keeps engines and fuel warm in cold weather. Through the use of TSE during stops, drivers sleep and awake better rested because noise, vibration and fumes are eliminated, leading to more alert and safer driving. TSE is a technology solution with two ways to reduce extended truck idling - on-board and off-board. On-board TSE combines battery storage on the truck with recharging at truck stops to power in-cab electric appliances, including electric heaters and air conditioning units. Off-board technologies provide heating and air conditioning infrastructure, Internet access, phone, television, movies and satellite programming at truck stops. The U.S. Department of Energy (DOE) has made a TSE locator available at www.eere.energy.gov/cleancities/idle/station_locator.html.  Both on-board and off-board technologies allow the trucks to turn off their engines, thus saving fuel and reducing air pollution. According to DOE's National Renewable Energy Laboratory (NREL), "Idle reduction systems could provide a number of efficiencies - including saving the U.S. trucking industry $2 billion annually, reducing diesel consumption by 800 million gallons per year, decreasing NOx emissions by approximately 150,000 tonnes per year and reducing PM emissions by up to 3,000 tonnes per year." The California Energy Commission has concluded that individual trucks could average savings of 1,800 gallons of diesel, 5 tonnes of NOx and 21 tonnes of CO2 annually.