OptiFuel developing near-zero emissions RNG-fueled locomotive

OptiFuel Systems said it is in the process of finalizing a $2.6 million U.S. Department of Energy (DOE) grant to demonstrate a pre-production Renewable Natural Gas (RNG) hybrid 4,300 hp line-haul locomotive.

The program will demonstrate that a suite of commercially available, EPA rail-certified engines present a near-term, low-risk solution to create an RNG hybrid line-haul locomotive with near-zero emissions.

This new program, partially funded with the DOE grant, will allow pre-production testing at AAR’s Transportation Technology Center (TTCI). It will also operate in-service with a regional railroad to validate that OptiFuel’s technology can also be applied in the higher horsepower freight and passenger locomotive market.

This program is integral to OptiFuel’s 5-year plan to disrupt and decarbonize the rail market with a full line of zero and near-zero NOx, PM and CO2 emissions freight and passenger locomotives.

In several weeks, OptiFuel aims to start taking orders, in 49 of the U.S. states, for a new 800 hp to 3,200 hp, 100 per cent natural gas freight and transit locomotives. All will have zero NOx/PM emissions with carbon-neutral emissions by consuming an RNG/CNG mixture.

OptiFuel has already developed and tested a high volume CNG/RNG refueling system at the Indiana Harbor Belt CNG locomotive program, utilizing CNG.

In the next 2 years, OptiFuel will be announcing additional refueling products, including a 12,000 DGE (Diesel Gallon Equivalent) CNG/RNG tender; and a 9,000 CNG/RNG DGE, 1,600 hp zero-emission, powered tender.

The Rail Sector is the only transportation modality without significant emissions-related development that is feasible in the near-term to eliminate ozone, smog and GHG emissions.

In comparison, the composite US freight line-haul fleet, which consumes 90 per cent of the fuel in the rail industry, emits 8 g/bhp-hr of NOx while new CNG Class 8 trucks emit 0.02 g/bhp-hr of NOx, a reduction of 400 times.

Besides the U.S. locomotive fleet average NOx emissions of 8 g/bhp-hr, the U.S. rail fleet’s average fine Particulate Matter (PM) emissions is 0.22 g/bhp-hr.

In comparison, OptiFuel’s 4,300 RNG hybrid line-haul locomotive is expected to emit 0.04 g/bhp-hr of NOx, a reduction of 200 times, and emit 0.00 g/bhp-hr of PM.

Using RNG as the fuel, OptiFuel’s locomotive will dramatically lower greenhouse gas (GHG) emissions resulting in a neutral or negative carbon footprint, in addition to far exceeding California’s Tier 5 locomotive petition standards to U.S. EPA.

This demonstration will include a comprehensive natural gas hybrid propulsion package featuring four 100 natural gas OptiFuel engines and a single Cummins Tier 4, EPA rail certified, diesel-powered QSK60 in a hybrid configuration.

The design also includes a 100 per cent battery-electric mode for limited yard operations. OptiFuel’s OFS12 engine is EPA rail certified with emissions of 0.00 g/bhp-hr for both NOx and PM, and is capable of operating on either CNG, RNG, LNG, or a CNG-RNG blend. The OFS12 engine, which is identical to the Cummins ISX12N for on-road applications, is the cleanest rail engine currently certified by EPA.

The pre-production locomotive will consume 83 per cent natural gas along with 20 per cent improved efficiency versus Tier 4 diesel line-haul freight locomotives. OptiFuel will utilize one of its proprietary, Federal Railway Administration approved onboard CNG/RNG storage system holding 1,500 DGE to complete the locomotive design.