Experimental investigation on the effects of gliding arc plasma on the combustion characteristics of air stratified NH3 flames
Year: 2025
Type: article
Abstract: This study investigates the impact of gliding arc plasma (GAP) on emission characteristics in NH 3 -air flames with premixing ratios ranging from 0 % to 25 % at global equivalence ratios (ϕ) of 0.8 and 0.9. The experiments are carried out in a dual swirl burner, where a premixed NH 3 -air mixture is introduced through the inner nozzle and central lance for GAP interaction, and non-premixed air is supplied via the outer nozzle. This study is the first to apply gliding arc plasma (GAP) to air-stratified ammonia flames, and this approach provides a significant and novel strategy for reducing NO x emissions. The results show that GAP reduces NO x emissions by up to 40 % under fully non-premixed conditions. At ϕ of 0.8, a critical transition appears when premixed air exceeds 20 %, resulting in increased NO emissions. In contrast, for ϕ = 0.9, GAP consistently maintains stable NO reduction across all tested premixing ratios. The spectral analysis of the flame shows that the OH and NH 2 radicals play a pivotal role in mediating the effect of GAP on NO formation. These radicals exhibit competing influences, with NH 2 formation favoured under plasma activation. The NH 2 radical primarily forms through two plasma-driven pathways: O( 2 D) + NH 3 → OH + NH 2 and N( 2 D) + NH 3 → NH + NH 2 . The observed reduction of NO with plasma is primarily due to the increased production of NH 2 related to OH. • First study to investigate the effect of plasma in air-stratified NH 3 flames. • Novel strategy to mitigate NOx emissions by up to 40 % in NH 3 -air flames. • NH 2 radicals are crucial in reducing NOx through plasma-activated reactions.
Source: Energy
Authors: Ziyu Wang, B. Aravind, Syed Mashruk, Agustin Valera-Medina
Institution: Cardiff University
Language: English
Subfield: Computational Mechanics
Field: Engineering
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,260
OpenAlex ID: W4414088445