Simulation Analysis of Methane Exhaust Reforming Mechanism Based on Marine LNG Engine

Abstract

LNG is a potential alternative fuel for ships. Generating H2 through exhaust reforming is an effective method to improve the performance of the LNG engine and reduce its pollutant emissions. It is necessary to study the mechanism of methane exhaust reforming to guide the design of the reformer. Based on the detailed mechanism, the characteristics of methane reforming reaction were studied for a marine LNG engine. Firstly, the reforming characteristics of exhaust were studied. The results show that methane reforming requires a lean oxygen environment, and the hydrogen production reaction will not occur when the O2 concentration is too high. Then, the effects of the O2/CH4 ratio (0.2–1) and H2O/CH4 ratio (0–2) on the reforming reaction were studied. The results show that under O2/CH4 = 0.4, the molar fraction of hydrogen at the outlet of the reactor decreases with the increase in the H2O/CH4 ratios. Finally, a mechanism analysis was conducted. The results show that an oxidation reaction occurs first and then the steam reforming reaction occurs on palladium-based catalysts.