Catalytica Energy Systems’ emissions control retrofit solution for mobile diesel engines has reduced NO_x emissions by more than 50% during preliminary in-house and on-vehicle testing.

The Catalytica system combines its XononD diesel fuel processing (XFP) technology with a NO_x adsorber catalyst system.

NO_x adsorbers require periodic regeneration, during which the trapped NO_x is catalytically reduced to nitrogen. One of the exhaust gas enrichment techniques is to inject diesel fuel upstream of the adsorber.

The Catalytica XFP converts a portion of the diesel fuel to reactive reductants that efficiently regenerate and desulfate the NO_x trap at low temperatures. This results in higher NO_x conversion and less of a fuel economy penalty on the system.

The system bolts onto the chassis of the truck, inline with the exhaust and with a fuel feed.

An OEM version (i.e., not retrofit, but integrated into the engine system) of the XononD technology delivers a projected 90% reduction in NO_x with approximately a 2%–3% fuel penalty in most engine conditions. No word yet on the fuel penalty for the retrofit application.

Based on the test results, Catalytica will begin a three-month, on-road demonstration of the retrofit system next month in Texas.

Catalytica also manufacturers the Xonon catalytic combustion technology for gas turbines. In a gas turbine, Xonon is an integral part of the combustor. As with traditional flame combustion, the fuel and air are supplied to the combustor. But rather than combust the fuel in a flame, the Xonon system combusts the fuel using a catalyst at lower peak temperatures (approximately 2,300ºF versus 3,000ºF). Fuel and air are thoroughly mixed before entering the catalyst where it is responsible for combusting the fuel to release its energy. The lower temperature of combustion reduces the NO_x produced.

Resources:

• Diesel emissions reduction program overview

• Use of a Diesel Fuel Processor for Rapid and Efficient Regeneration of Single Leg NOx Adsorber Systems.