The unique chemistry of methane combustion, including strong C-H bond energy, leads to difficulties in use of natural gas as an engine fuel. Problems include low combustion efficiency, knocking, unreliable ignition (misfiring), and NO_x emission. It is well established that improvement of the above-mentioned combustion phenomena requires the presence of high concentration of chain-initiating and chain-branching reactive radicals. This project explores a novel approach called Infrared Multiphoton Dissociation (IRMPD), for producing reactive radicals. IRMPD involves the absorption of multiple infrared photons by target molecules within the duration of an infrared laser pulse, leading to formation of high energy species. This study is an exploration of the applicability of IRMPD to natural gas excitation, and subsequent enhancement of combustion. IRMPD is demonstrated to be a feasible concept for natural gas engine ignition and for combustion enhancement through reduction in ignition delay time. The next stage of development would be to identify and implement a prototype laser and optical hardware for single-cylinder engine tests.

Date Published: 24 May 1993
PDF: 12 pages
Proc. SPIE 1862, Laser Applications in Combustion and Combustion Diagnostics, (24 May 1993); doi: 10.1117/12.145709

Published in SPIE Proceedings Vol. 1862:
Laser Applications in Combustion and Combustion Diagnostics
Larry C. Liou, Editor(s)