Wednesday, November 12, 2014

Four paths to natural gas

Written by  William C. Vantuono, Editor-in-Chief
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LNG or CNG? At the High Horsepower Summit in New Orleans, four newer players in the natural gas-powered-locomotive field described their plans.

Based on the strong attendance at rail-related presentations at the 2014 High Horsepower Summit, hosted in New Orleans by Gladstein, Neandross & Associates, interest in LNG (liquefied natural gas) or CNG (compressed natural gas) as a cost-effective alternative to diesel fuel is high. While BNSF, Union Pacific, and CN pursue blended-fuel technology (LNG plus a small percentage of diesel to initiate compression ignition) with EMD and GE Transportation (RA, September 2014, p. 28), others are pursuing somewhat different strategies.

At HHP Summit 2014, Norfolk Southern, CSX, Indiana Harbor Belt, and Farmrail revealed their plans for natural gas.

NS: CNG mother-slug

"Natural gas is one of those things you can't ignore," said NS Manager-Locomotive Engineering Allen Rider. "Is a huge fuel cost savings possible, or is this just a flash in the pan? NS has opted for a CNG-powered mother-slug locomotive set, with a spark-ignited engine, and fuel storage on the slug. "This will be based on our successful GP40-2 and RP-E4C design," said Rider. "The slug's engine area is usually filled with ballast for weight, so it's an ideal spot for CNG cylinders."

The mother is an EMD GP38-2, NS no. 5053. "The gas lines are installed, and we're working on wiring and electronics. Our expected completion is Dec. 1, 2014," said Rider. The CNG engine is a roots-blower-equipped EMD 16-645E modified with an ECI (Energy Conversions Inc.) Spark Ignited Prechamber kit.

In the slug, eight type-1 steel CNG cylinders, 24 inches wide by 22 feet long, provides 1,025 DGE (Diesel Gallon Equivalent) storage @ 4,500PSI. The slug, NS no. 799, is built on a GP50 frame, with NS's new-design, crashworthy "Admiral Cab."

"Our first priority will be emissions testing at Altoona," said Rider. "The FRA has seen the unit, and has provided a positive response. We're about to start the formal request process for FRA testing approval. Initial operational testing will be in the Altoona region, followed by a metropolitan area, possibly Atlanta, Pittsburgh, or Chicago."

NS, said Rider, "sees this concept as an alternative low-emissions solution. We have 50 new EMD 4,300-hp SD70ACes coming in the fourth quarter with dual-fuel natural gas provisioning. It's likely that two will be fully equipped for DGB (Dynamic Gas Blending) in 2015. We've written a specification and issued a request-for-quotes for a prototype CNG tender and compressor system. We're looking for 5,000 DGE minimum capacity, 90-minute fill time, and crashworthiness. With CNG, the tender and compressor technology need to be closely matched."

Why CNG? Explained Rider: "CNG is about $0.50 to $1.00 lees per DGE than LNG. Our shorter corridors—Chicago–New Jersey, 875 miles; Chicago–Atlanta, 744 miles, Atlanta–New Jersey, 847 miles, or Chicago–Jacksonville, 1,095 miles—favor CNG. No glycol heating loop is needed. There are no concerns about storage time. CNG is not cryogenic, thus it may be perceived as safer, and can be odorized. CNG needs a large compressor system, rather than a liquefaction plant. Railroad personnel can operate and maintain the compressors, and the infrastructure easier to build and scale up."

"On the other hand," Rider said, "truck to locomotive DTL (Direct to Locomotive) fueling is impractical. We will need to build CNG infrastructure right away. A larger-scale operation favors LNG. CNG fill times are longer, even with advanced technology, and interchangeability with other railroads may be a problem. We're certainly not ruling out LNG, but CNG is an option worth seriously investigating."

CSX: NUMEROUS considerations

"Our initial estimate for the fuel cost differential, or savings, is about $400 million of our $1.6 billion annual fuel expense," said CSX Director Locomotive Engineering John Rimer. "While this is substantial, a very sizable capital investment is required to capture the savings. We are working to understand the magnitude of the capital investment. Also, some experts believe that there is a risk that the spread between oil and natural gas could decrease, from either rising gas prices or lower oil prices. Therefore, we will be very focused on various mechanisms to decrease that risk."

Rimer also noted that the potential exists to further reduce CSX's environmental footprint through the use of natural gas.

Safety concerns "are being evaluated," said Rimer. "The properties of LNG do not present a deterrent to continued evaluation as a railroad fuel, but it does change CSX's risk profile. LNG quickly evaporates and is colorless and odorless, so methane (gas) detection is needed to prevent asphyxiation and/or fire. Though LNG has outstanding safety record over past 50 years in ships and trucks, rail poses a very different operating environment with different challenges. We're working with the AAR, FRA, and LNG safety experts to better understand the safety implications of transitioning to LNG, as there are still a lot of unknowns."

Will the spread between natural gas and diesel justify the costs of a widespread conversion?, or make sense only in select locations? "The costs of converting are very high and rising," said Rimer. "This includes tender cars and locomotive retrofits, retrofitting locomotive servicing facilities, and LNG fueling infrastructure. Operational transition—locomotive dispatch, fueling and repair—will be difficult. Availability of fuel, tender cars, and locomotives and/or retrofits will be vital."

"We will continue to advance our partnership with GE on dual-fuel technologies," said Rimer. "We are also investigating the availability and feasibility of other technologies evolving in the industry. LNG fuel Supply and equipment is likely to be available in 2017. This includes new fuel supply sources through existing facility expansions and new small- to mid-scale facilities. We expect to see multiple configurations of dual-fuel locomotives and retrofit kits both for CNG and LNG applications. If we continue to more forward with natural gas, it will be in a measured fashion. Our focus will be on LNG for high-fuel-burn moves, on CNG and/or LNG for short closed-loop cycles and yard operations, and at locations in close proximity to fuel supplies and repair facilities."

IHB: Total fleet conversion

On the Indiana Harbor Belt, 31 of the railroad's 46 locomotives are funded for conversion to natural gas. "IHB is committed to moving our entire fleet to CNG as the primary fuel source," said Director of Purchasing and Project Manager Michael Nicoletti. "This is not a pilot project—it's the first planned fleet-wide conversion to occur in the nation. Our program begins in 2015 and is projected to end in 2019. We believe we can reduce our annual PM (Particulate Matter) emissions by 97%, and cut greenhouse gas emissions by 50%."

IHB's program is funded through a CMAQ (Congestion Mitigation/Air Quality) grant subsidized by the Chicago Metropolitan Agency for Planning (CMAP), USDOT, US EPA, and the states of Indiana and Illinois.

"Railroad industry experience with CNG is very limited," said Nicoletti, "so we've sought out natural gas experts from the energy field. We're engaged with locomotive vendors for creative solutions, which will not include a fuel tender car. As well, FRA has been actively engaging us in this first-in-the-nation implementation."

Farmrail: Comprehensive assessment

Farmrail System Inc.'s Short Line Locomotive CNG Fueling Program "is meant to verify the freight operation reliability of CNG," according to Alternative Fuels Specialist Leslie Olsen. "We'll be evaluating locomotive and fuel availability, extended mean days between failure, and if power and maintenance are comparable with diesel. The Oklahoma DOT encourages natural gas for transportation fuel, and we're an existing ODOT partner.

Farmrail's program, which is focused on minimize diesel usage, will involve an assessment of economics, engine technology, fuel and employee safety, operation and maintenance rules, and public safety. The railroad is developing a guidebook for this purpose. Like IHB, Farmrail does not want to operate with a fuel tender, and as such is looking for onboard CNG storage. "We're researching a spark ignition conversion of an existing EMD engine," said Olsen. "There is one source for current-engine retention, ECI, with 10 years of proven safe operation on the Napa Valley Wine Train. ECI's fuel storage design provides 600 DGE, and its EMD conversion technology is reliable over 25-year period.

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