High-Pressure Oxidation of Ammonia Mixed with Dimethoxymethane

Area of Science:

• Chemical Kinetics
• Combustion Science
• Environmental Chemistry

Background:

• Ammonia (NH3) is a promising carbon-free fuel, but its combustion characteristics require detailed understanding.
• Dimethoxymethane (DMM) is a potential additive to improve combustion and reduce emissions.
• High-pressure combustion of NH3-DMM mixtures is relevant for advanced energy systems.

Purpose of the Study:

• To experimentally and kinetically investigate the high-pressure oxidation of NH3-DMM mixtures.
• To determine the influence of pressure, equivalence ratio, and DMM concentration on NH3 and DMM conversion.
• To identify the main reaction pathways and emission products, particularly NOx.

Main Methods:

• Experiments conducted in a tubular flow reactor at pressures of 10-40 bar.
• Temperatures ranged from 650-1250 K under various equivalence ratios (0.7-3).
• Detailed chemical kinetic modeling was used to interpret experimental data.

Main Results:

• NH3 and DMM conversion were enhanced by higher pressure and increased O2 and DMM concentrations.
• Dominant conversion pathways yielded N2/N2O and CO/CO2.
• NO and NO2 concentrations were below detection limits, indicating potential for NOx reduction.

Conclusions:

• The kinetic model accurately captured experimental trends for NH3-DMM oxidation.
• DMM addition enhanced NH3 reactivity and influenced CO2 formation pathways.
• The study suggests that NH3-DMM combustion under these conditions can lead to significant NOx emission reductions.