Membrane dielectric barrier discharge plasma for low-temperature NOx abatement from hydrogen-ammonia combustion exhaust
Year: 2026
Type: article
Abstract: The transition to carbon-free fuels, including hydrogen-ammonia blends, is essential for decarbonizing transportation but can increase nitrogen oxide (NOx) emissions, particularly during cold-start operation. Because selective catalytic reduction (SCR) requires elevated activation temperatures, complementary low-temperature, rapid-response technologies are needed. This study evaluates membrane dielectric barrier discharge (mDBD) nonthermal plasma for NOx abatement under simulated engine-exhaust conditions with 2–10% O 2 , based on emissions from H 2 /NH 3 combustion in spark-ignition and compression-ignition engines. Reactor behavior was characterized using optical emission spectroscopy (OES), electrical waveform analysis, a nonlinear electric circuit model, and an electron–gas two-temperature (2 T) fluid dynamic model. The discharge transitioned from a highly dynamic filamentary regime at low applied power to a stable, volume-filling glow regime at high applied power. Increasing oxygen concentration did not substantially affect the total dissipated plasma power but altered energy partitioning, though the precise magnitude of these thermal shifts is obscured by known diagnostic quenching artifacts in oxygen-rich mixtures. NOx abatement revealed a clear operating trade-off: high-power glow conditions achieved the highest absolute NOx conversion, approaching 95% at 0% O 2 , but with lower energy efficiency, whereas low-power filamentary conditions maximized energy efficiency, up to 4 mg NOx /kJ, at the expense of bulk conversion. Oxygen concentrations of 6% and above inhibited overall NOx abatement by promoting NO regeneration. The use of a green membrane provided only a temporary improvement, after which performance stabilized near the seasoned-membrane baseline. These results establish mDBD plasma as a promising complement for transient cold-start NOx control and highlight key trade-offs among power, oxygen concentration, and membrane conditioning.
Source: Fuel
Institutions: University of Massachusetts Lowell, Stony Brook University
Language: English
Subfield: Radiology, Nuclear Medicine and Imaging
Field: Medicine
Domain: Health Sciences
Open Access status: hybrid
Estimated APC paid: $4,330
OpenAlex ID: W7222831182