Characterization and Reduction of In-Use CH Emissions from a Dual Fuel Marine Engine Using Wavelength Modulation Spectroscopy.

In-use exhaust stream CH emissions from two dual fuel marine engines were characterized and strategies for CH reduction were identified and evaluated. For this, a low-cost, portable, wavelength modulation spectroscopy (WMS) system was developed. The performance of the developed WMS sensor was assessed using gas standards and demonstrated on a heavy-duty, diesel pilot ignited, direct-injection natural gas research engine through comparison to a flame ionization detector.