World Bank Supports Chinese Coal to Dimethyl Ether Project
Honda UK’s “While-U-Wait” Carbon Offsets for Civic Hybrid Buyers

Demonstration Begins of New Diesel Emissions Treatment System for Locomotives

Rendering of ALECS (the “hood”). Click to enlarge.

The demonstration of a new system to capture and treat emissions from diesel train locomotives is beginning today at the Union Pacific railyards in Roseville, California.

The Advanced Locomotive Emission Control System (ALECS) applies technology used to capture emissions from industrial plants to near-stationary locomotives.

The ALECS includes a stationary emissions treatment unit that is connected to diesel locomotives with flexible ducts and a hood designed to fit over and attach to the exhaust stacks.

The ALECS emission treatment system. Click to enlarge.

Diesel-related emissions are then captured and treated rather than being released into the air. The system will be used on locomotives that are idling or undergoing engine load tests, and will allow for some train movement so that there is minimal disruption to maintenance and testing operations.

The demonstration system is sized to handle 12,000 scfm of exhaust—sufficient to treat one line-haul locomotive at full power or six locomotive at idle. ALECS can be upsized to as much as 40,000 scfm capacity.

The ALECS technology can be used to treat various types of internal combustible engines burning a variety of diesel fuels. The Roseville demonstration will include two different locomotive types and results will be captured in a final report expected in November 2006.

ALECS is expected to reduce sulfur dioxide by 99%, particulate matter by 99%, nitrogen oxide by 95% and water-soluble volatile organic compounds by 50% from captured and treated locomotive emissions. All of these pollutants are significant contributors to poor air quality anywhere diesel engines are present.

Specifically, the demonstration is expected to result in annual reductions of 102.5 tons of NOx and 2.2 tons of PM.

If proven effective through the demonstration project, the system could be used more extensively at the Roseville facility or similar railroad operations throughout the country.

The Union Pacific 950-acre J.R. Davis Rail Yard in Roseville services more than 30,000 locomotives annually, making it the largest service and maintenance rail yard in the West.

A partnership of local, state and federal agencies, along with private business, is funding and managing the $1.75 million demonstration project. The partners include the Placer County Air Pollution Control District, Advanced Cleanup Technologies, Inc. (ACTI)—developer of the ALECS—Union Pacific Railroad, U.S. Environmental Protection Agency, Sacramento Metropolitan Air Quality Management District, South Coast Air Quality Management District, the City of Roseville and the California Air Resources Board.

Following the Roseville demonstration project, the system will be reconfigured as an Advanced Maritime Emissions Control System (AMECS) at the Port of Long Beach to demonstrate its effectiveness in capturing and treating emissions from ships loading and unloading cargo in port. The capacity of the system (12,000 scfm) will remain the same.




The most advanced locomotive engine i'm aware of is called the Jet Train, a jet engine, a tubojet. Reports say it's a lighter engine with more horsepower and better fuel economy. I believe Bombardier is the manufacturer, Canadian. Now, if this new engie can have its emissions check'd, there'd be an even better improvement.

Tim Russell

The main problem with turbines is often high NOx. Any word on the emmissions end of this?

John Ard

Could this system be scaled down and use onboard the train?


Turbojets deliver their output as thrust, not shaft power.  Further, gas turbine engines are not as efficient as diesels, especially at part load (otherwise they would have taken over years ago).

Full application to locos themselves looks doubtful; the SCR NOx system and particulate filter might work well, but anything which involves heaters to drive an oxidation catalyst is going to hurt fuel economy.


This appears to be a stationary system only.

I would add to Engineer-Poet's post, that heaters required to drive an oxidation catalyst could obtain their energy from the exhaust manifolds.

The comments to this entry are closed.