WHY SHOULD truck fleets consider natural gas as a replacement for diesel fuel? Is natural gas readily available where trucks go, and how easy is it to handle? Does natural gas offer potential as a new cargo for tank truck carriers?
Which is the better option for trucking: compressed natural gas (CNG) or liquefied natural gas (LNG)? How proven is the natural gas engine technology, and what are the engine choices? How many truck builders offer factory-installed natural gas engines?
Over the past six months or so, Bulk Transporter sought out answers to these and other questions on what natural gas means to tank truck fleets as a replacement fuel for diesel. This special report looks at the upside and downside for natural gas.
Far and away, the biggest benefit is the sheer amount of natural gas available in the United States and the rest of North America. The latest reports indicate that the United States has well over 100 years worth of proven supplies of natural gas, and some are calling this country “the Saudi Arabia of natural gas.”
Largest producer
A recent report from the National Petroleum Council states that the United States now ranks as the largest producer of natural gas, and the United States and Canada together account for 25% of the world's proven natural gas supply. Combined with oil and coal reserves, natural gas gives the United States the capability to be fully energy independent.
“In April of this year, oil imports accounted for about 60% of our three-year-high trade deficit of $50.2 billion,” says Andrew J Littlefair, president and chief executive officer of Clean Energy Fuels Corp. “Converting America's heavy truck fleet of about eight million vehicles to [LNG] would save 2.5 million barrels of oil per day, meaning we could reduce our reliance on OPEC oil by half. At $100 per barrel, that means $250 million per day stays in the United States to circulate through our economy, rather than being shipped overseas.
“Currently priced $1.50 to $2 lower than diesel or gasoline (depending on local markets), the use of natural gas fuel reduces costs significantly for vehicle and fleet owners and reduces greenhouse gas emissions up to 30% in light-duty vehicles and 23% in medium- and heavy-duty vehicles.”
Richard Moskowitz, American Trucking Associations vice-president and regulatory affairs counsel, adds the US trucking industry understands the importance of breaking our dependence on foreign oil. “Natural gas is a domestic fuel that we can access today as a replacement for diesel,” he says. “The US trucking industry currently consumes 35.6 billion gallons of diesel annually at a cost of around $137.8 billion. It is the industry's highest operating cost.”
A recently released Frost & Sullivan research report entitled “Strategic Analysis of the North American Class 6-8 Natural Gas Truck Market” predicts that the natural-gas-fueled commercial truck population will grow from 1,950 vehicles now to more than 29,483 vehicles in 2017. Fuel prices will be a key factor driving that change.
Fleets interested
Trucking companies clearly are looking at natural gas as a way to lower fuel costs, and tank truck fleets are among those taking a leading role. Tank fleets that have made a significant commitment to natural gas over the past year or so include Heckmann Corp, 200 LNG-fueled tractors (cover story in this issue of Bulk Transporter); Vedder Transport Ltd, 50 LNG-fueled tractors; Fair Oaks Farms, 42 CNG-fueled tractors (September Bulk Transporter cover story); Dillon Transport, 24 LNG-fueled tractors; and Trimac Transportation Inc, 14 LNG-fueled tractors.
The natural gas truck engine technology available today definitely works, according to Charles Musgrove, vice-president of Dillon Transport. In addition, many shippers respond very favorably to a fleet that is running a clean technology, like natural gas.
“That is a big time selling factor with some of our customers,” he says. “We also benefit by running a stable, lower-cost domestic fuel. We have cut our fuel costs by around 30% compared to diesel.”
Dillon Transport's natural gas fueled tractors are being used with dry bulk trailers to haul roofing materials on designated routes in Texas and Ohio. For instance, the main Texas traffic lane is between Dallas and Houston (a 247-mile trip), and the trucks have access to LNG at Dillon Transport's Dallas terminal and at a Clean Energy LNG plant on the north side of Houston.
The engines have taken some getting used to, and the carrier had to make some compromises when specifying the natural-gas fueled tractors. The tank truck carrier chose the 8.9-liter Cummins Westport ISL G engine with spark ignition and three-way catalyst for emission treatment. An LNG fuel tank with an 81-gallon diesel equivalent gives the tractors a range in excess of 400 miles.
“We chose the ISL G and LNG fuel for several reasons,” Musgrove says. “Those factors enabled us to keep tractor tare weight in the 14,000-lb range. With the spark ignited ISL G, we didn't need the heavy emission treatment systems now required on diesel-fueled trucks. In addition, natural gas in liquefied form can be carried in smaller fuel tanks. We put just one fuel tank on our tractors.
“There is a learning curve with the new equipment, and one challenge for our drivers was becoming comfortable with the range our tractors have with LNG. They wanted assurance that they had enough fuel to complete each trip.
“We are finding that the 8.9-liter engine isn't quite big enough for 80,000-lb tanker operations in some cases. We've had to tweak the engine settings to get the performance we need. Natural gas fueled trucks definitely provide the best return on investment in high-volume traffic lanes. In addition, you've got to run where the fuel is most available.”
Challenging experience
Trimac Transportation Inc also has seen the potential of natural gas and some of the challenges. “We've been running LNG-fueled trucks in the United States for about a year and a half now, and we're studying some opportunities to put these trucks in Canada,” says Jeff McCaig, chairman and chief executive officer of Trimac Transportation. “This is an environmentally friendly fuel, and it costs less than diesel. However, there are some issues that need to be resolved.”
Trimac's LNG-fueled tractors in the United States are used to transport cryogenic products, specifically LNG, on a single traffic lane in Texas between Beaumont and Houston (an 88-mile trip). The tank truck carrier chose Kenworth T800 tractors with the 15-liter Westport GX engine that is built on the Cummins ISX platform and runs on a natural gas/diesel mix.
This big bore engine matches up well with tank fleets hauling maximum payloads, and drivers say the trucks have plenty of pulling power. The slip-seat operation keeps the rigs running virtually around the clock.
The tank truck carrier's experience with the LNG-fueled tractors is outlined by Bill Marchbank, vice-president of operations at Trimac Transportation. “We've had quite a few mechanical issues with the engine, fuel tanks, and fuel system,” he says. “The injection system is getting plugged. All of this has added up to unplanned downtime and frustrated drivers.”
Marchbank adds that Kenworth and Westport have been very good to work with, and they are trying hard to fix the problems. The vendors conducted a parts replacement campaign, but they haven't been able to precisely pinpoint the source of the mechanical issues.
“That said, we still believe in natural gas as a truck fuel,” Marchbank says. Natural gas is an abundant, cleaner, and cheaper fuel that comes from domestic sources. Natural gas fueled engines can work for bulk hauling. If we can get the problems worked out, we'll move more in this direction.”
California project
Beyond tank truck fleets, Ryder System Inc has made a major commitment to natural gas fuel for commercial trucks. The specialist in commercial transportation and supply chain management solutions is a key participant in a joint public/private partnership that includes the Department of Energy, the California Energy Commission, San Bernardino Associated Governments, and Southern California Association of Governments. Their project is investing $38.7 million in 202 natural gas-fueled vehicles for lease or rent; three strategically located natural gas compliant maintenance shops in Rancho Dominguez, Orange, and Fontana; and two fueling stations. All of the trucks should be delivered by the end of this year.
“We're very enthusiastic about the California program, and we plan to expand our natural gas truck effort into other areas,” says Scott Perry, vice-president of supply management for Ryder Fleet Management Solutions. “We're already working with customers in Arizona, and we are evaluating several opportunities on the East Coast.
“We believe natural gas trucks have a place in the Midwest and Texas. Customer application is a critical factor. Many natural gas trucks are going into refuse collection, local delivery, and pickup and delivery. Some bulk hauling applications could be good candidates.
“The shift to natural gas will be gradual, but this is a good green technology with lots of benefits. Natural gas has a place as a vehicle fuel in the market, and we are moving forward. It just makes sense.”
Fueling infrastructure
Clearly many in the trucking industry agree with Perry, but they also express frustration with the slow growth of the fueling infrastructure. For those wanting to take the plunge into natural gas, the biggest drawback has been — and continues to be — fuel availability where the trucks are running. It would be very difficult for CNG-fueled trucks — and virtually impossible for LNG-fueled trucks — to run coast to coast.
Perry agrees that the fueling infrastructure is a major issue. “We must build out the infrastructure,” he says. “We need more filling stations that are specifically designed to handle commercial vehicles.”
The natural gas production and marketing sector acknowledges the need for more natural gas fueling infrastructure, but it is sometimes hard to justify investment in a facility that might have limited demand initially.
“This is a classic chicken-and-egg scenario,” says David Hill, vice-president of operations for Encana Natural Gas Inc. “We realize that co-evolution is the only answer. We have to do it all at the same time — expand the infrastructure even as we put increasing numbers of natural gas fueled trucks on the road.”
Steady growth
To keep up with a steadily growing population of natural gas-fueled vehicles, Hill says the infrastructure is growing by about a 10% compounded annual rate. “The infrastructure is developing, and we are seeing more filling stations open than close,” he says.
Approximately 930 CNG and 45 LNG retail filling stations currently are open across the United States to commercial vehicles, compared with thousands of locations that sell diesel fuel. The largest concentration of natural gas fueling stations can be found in California and neighboring southwestern states. That is changing, though.
“California served as a good incubator for this fuel and technology, in large part because of Clean Truck Program that was focused on the Ports of Long Beach and Los Angeles,” Hill says. Well over a thousand natural gas-fueled tractors were purchased under that program by California drayage fleets.
“The Gulf Coast region — particularly Texas — will catch up very quickly because considerable LNG fueling capacity is being added in the area,” he adds. “States that recently approved incentives to spur fueling infrastructure include Arkansas, West Virginia, Louisiana, Oklahoma, Pennsylvania, and Texas.”
Big stir
Chesapeake Energy Corporation created an industrywide stir earlier this year when it announced that it was investing $150 million to stimulate fueling infrastructure development. The investment is dedicated to funding the construction of approximately 150 LNG fueling stations at strategic truck-stop locations along major trucking corridors to form the backbone of “America's Natural Gas Highway.”
Clean Energy has partnered with Chesapeake Energy for the project. Many of the LNG fueling stations will be co-located at Pilot-Flying J Travel Centers. Clean Energy already had an agreement with Pilot-Flying J to build, own, and operate publicly accessible CNG and LNG fueling facilities at specific Pilot-Flying J Travel Centers.
Following on the heels of the Chesapeake Energy announcement, the Texas state government passed legislation to promote an aggressive expansion of natural gas fueling facilities in the Texas Triangle — Austin, Dallas/Fort Worth, Houston, and San Antonio. The primary focus is on the interstate highways connecting those cities, and Clean Energy has announced it plans to build 12 natural gas fueling locations on those routes.
Encana opened publicly accessible natural gas fueling facilities in Colorado, Louisiana, and Alberta, Canada, over the past couple of years. Encana also can provide mobile LNG fueling systems for temporary use or when a permanent fueling facility isn't practical. Mounted on a trailer frame, the self-contained systems hold 4,500 gallons of LNG.
Love's Travel Stops has announced plans to open 10 new CNG fueling stations in Oklahoma. The facilities will be built and operated in cooperation with Chesapeake Energy. Construction starts in December.
Georgia utility regulators recently approved an incentive program to encourage private-sector investments in to develop CNG filling stations across the state. The program would help fund construction of up to 10 stations over the next five years.
Natural gas filling stations are pricey to say the least. Construction costs range from $600,000 to $1.5 million per facility.
Filling stations are just one aspect of the infrastructure that is needed to support commercial trucks. Investment in maintenance facilities also will be needed. New and existing shops will need explosion-proof wiring and lighting, high-capacity ventilation, methane detection systems, and fire suppression capability. All of this will cost $300,000 to $500,000 per location. Mechanics will need additional training to be able to work safely on trucks fueled with natural gas.
Fuel choice
A big question for many fleet operators is whether to run CNG or LNG. Each form of natural gas has its pluses and minuses. CNG is most readily available across the United States because it can be taken directly off local natural gas pipelines, and it is the easiest to handle. In addition, CNG provides a 28% reduction in CO2 emissions, while LNG offers an 18% drop. CNG has been the natural gas fuel of choice for city bus operations, local delivery fleets, and trash trucks.
The big downside for CNG is that it requires a large amount of fuel storage space on a truck, and the tanks are heavy. Five 15-gallon CNG tanks (enough for a 330- to 350-mile range) weigh 1,200 pounds. CNG has a 4:1 fuel storage ratio when compared with diesel. In contrast, comparable LNG fuel storage has a 2:1 ratio compared with diesel.
More efficient fuel storage makes LNG a more attractive fuel for regional, longhaul, and high-mileage truck fleet operations. Cooled to -260 F, LNG has an energy density around 60% of diesel, which makes it very good for longhaul trucking. LNG works best in operations where trucks are running hard, because stored fuel boils off and is lost if a truck is parked for a number of days.
Engine options
Engine choices have gotten better, and the technology certainly has come a long way. Truck fleets can choose between two natural gas engine technologies: spark ignition and compression ignition. The spark ignition engine has a fuel economy penalty of 7% to 10% compared to diesel, while the compression ignition engine is more or less 1%. The spark ignition engine burns only natural gas (CNG or LNG), while the compression ignition engine is a dual-fuel system that burns diesel and natural gas.
Emission control technology on a spark ignition engine is a relatively simple three-way catalyst. In most cases, the compression ignition engines will need an emission control system that includes selective catalytic reduction and a diesel particulate filter.
The two factory-installed natural gas engines currently available in North America are manufactured through a partnership between Cummins Engine and Westport HD. The nine-liter Cummins Westport ISL G uses spark ignition, and the 15-liter Westport GX is based on the Cummins ISX and uses compression ignition.
Many in the industry say there is a big gap between the two engines. A greater variety of displacement is needed. “There are gaps to be filled,” Hill says. “At the very least, the engine builders need to add 11-liter and 13-liter natural gas engines.”
A Cummins Westport 11-liter ISL G reportedly will be ready for the market in 2013. In addition, some of the truck manufacturers reportedly are working on their own natural gas fueled engines in the 13-liter range.
A majority of the heavy-duty truck builders in North America are selling natural gas-fueled vehicles. Kenworth and Peterbilt offer a range of trucks with either the nine-liter Cummins Westport ISL G or the 15-liter Westport GX.
Daimler Trucks North America's Freightliner unit sells several models with the nine-liter ISL G engine, and the company plans to offer the 11-liter ISL G in its flagship Cascadia model, according to TJ Reed, Freightliner director of product marketing.
“We are very committed to natural gas, and we see a good future for the fuel,” Reed says. “Customers are asking a lot about natural gas as a truck fuel right now, and it will continue to play a role in the Freightliner product line. However, DTNA has no plans at this time to offer natural gas engines in Western Star trucks.”
Volvo Trucks has begun offering the VNM daycab tractor with the Cummins Westport ISL G natural gas engine. In Europe, Volvo reportedly is working with Clean Air Power Ltd on a dual-fuel compression ignition engine.
The natural gas focus at Mack Truck remains on the refuse hauler vocational market. According to some projections, natural gas engines will be specified in at least half of the refuse trucks ordered in 2012.
Earlier this year, Navistar International Corp displayed a prototype International ProStar+ powered by a 13-liter MaxxForce dual-fuel engine developed in partnership with Clean Air Power. The engine runs on 85% natural gas and 15% diesel. No launch date has been announced.
Natural gas technology adds $40,000 to $80,000 to the price of a new tractor. The price premium will remain until order volumes for natural gas truck increase to the point that manufacturers can achieve economies of scale.
Although federal grants for natural gas-fueled vehicle purchases have expired, but some states offer at least limited incentives to invest in the clean-fuel technology. The lower cost of the fuel offers the primary return on investment.
Fuel and cargo
For tank fleets, natural gas is more than a fuel. It's also a potential new cargo. While pipeline distribution of CNG is widespread, it's a different story for LNG. “We will have to distribute LNG by truck, because it isn't practical to move the liquefied product by pipeline,” Hill says.
LNG liquefaction plants and storage facilities currently are widely dispersed across the United States. That means relatively long hauls for the carriers in some cases. Hill suggests trips might range from 100 to 600 miles from the liquefaction plants.
Hill adds that tank fleets with experience hauling propane should have no difficulty making the move to LNG. The fuel is transported as a hazardous material in 10,000- to 12,000-gallon cryogenic tank trailers rated at 170 psi. The trailers cost $200,000 to $300,000.
Weighing 3.7 pounds per gallon, LNG is non flammable in the liquid state. As it warms up, it vaporizes and quickly disperses. There is no pooling. “LNG is safer than other liquid fuels,” Hill says.
With so much potential, natural gas is almost certain to find its place as a truck fuel. ♦
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