Emitec combines particulate matter filter and oxidation catalyst for rail
Emitec, a metallic-substrate exhaust aftertreatment system developer, is introducing an aftertreatment system to meet EU Stage 3b emission levels in locomotives. Emitec has been working on a concept study for the rail industry for a while, said the company, and is offering its PM-Metalit filter in combination with a diesel oxidation catalyst, both housed within the silencer. For the simultaneous reduction of NOx, a selective catalytic reduction (SCR) catalyst can be installed in the same silencer housing.

The aftertreatment system by Emitec is housed under the locomotive’s roof and replaces the silencer. It comprises two diesel particulate filters (DPFs) in the front, the urea injection system, followed by the SCR catalyst.

The system is also very suitable for retrofit applications, and Emitec illustrated the results of field testing on a demo VT646 locomotive. The vehicle was equipped with a Tier 2 550 kW diesel engine featuring a 22 L displacement. The installed aftertreatment realized together with Swiss company Tehag AG consisted of two diesel particulate filters (DPFs) and an SCR catalyst with a urea dosing system.

The retrofitted installment replaced the silencer. According to Emitec, the first tests in real operation showed a very low exhaust gas temperature. However, it was possible to achieve an approximately 60% NOx reduction in the first test without major adjustments in the SCR control, said the company. The company is also participating in a project by Union Pacific and Progress Rail Services in the United States, operating a diesel PR30CLoNOx locomotive, designed for low emissions and which is being tested in intermediate line-haul service in Texas, U.S.A.

The PR30C-LoNOx has been repowered with Tier 2 engines delivering 3728 kW. Emitec catalyst substrates were retrofitted to the locomotive a diesel oxidation catalyst upstream, plus an SCR system. Initial measurements indicated a NOx reduction of more that 90% compared to the levels emitted with the old engine.

Source: www.dieselgasturbine.com

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