Plasma-Assisted Combustion Technology for NO_x Reduction in Industrial Burners

Abstract

Stronger regulations on nitrogen oxide (NOx) production have recently promoted the creation of a diverse array of technologies for NOx reduction, particularly within the combustion process, where reduction is least expensive. In this paper, we discuss a new combustion technology that can reduce NOx emissions within industrial burners to single-digit parts per million levels without employing exhaust gas recirculation or other NOx reduction mechanisms. This new technology uses a simple modification of commercial burners, such that they are able to perform plasma-assisted staged combustion without altering the outer configuration of the commercial reference burner. We embedded the first-stage combustor within the head of the commercial reference burner, where it operated as a reformer that could host a partial oxidation process, producing hydrogen-rich reformate or synthesis gas product. The resulting hydrogen-rich flow then ignited and stabilized the combustion flame apart from the burner rim. Ultimately, the enhanced mixing and removal of hot spots with a widened flame area acted as the main mechanisms of NOx reduction. Because this plasma burner acted as a low NOx burner and was able to reduce NOx by more than half compared to the commercial reference burner, this methodology offers important cost-effective possibilities for NOx reduction in industrial applications.

Experimental Investigation of Premixed Methane–Air Combustion Assisted by Alternating-Current Rotating Gliding Arc

“…From the massive production of CO and H 2 under the stoichiometric and fuel-rich condition, we speculate that the plasma also promotes the production of CO and H 2 as intermediates in the lean combustion process and, therefore, enhance the stability of flame. Furthermore, the fuel-reforming effect of plasma under the fuel-rich condition shows a good prospect for the application of staged combustion [24].…”

Dynamics of a Lean Flame Stabilized by Nanosecond Discharges

“…The ignition probability is higher and the performances are better than with conventional spark discharges [9], [10]. Control of thermoacoustic instabilities [11], [12] and reduction of Nitrogen Oxides (NOx) [13] are also obtained using NRP and microwave discharges. Three combustion-enhancement effects have been evidenced: thermal, kinetic and hydrodynamic.…”

Electrically Driven Supersonic Combustion

“…The second, applied, approach is dealing with more practical schemes of combustion devices aiming towards reliable ignition, mixing intensification, flame stabilization, enhancement of combustion completeness, and pollution control. Referencing just a few, the papers [1,[16][17][18][19][20] give an initial impression on the field of PAC applications. In recent years, a few schemes of plasma-based actuators for supersonic combustion have been tested for flameholding purposes at flow conditions where self-ignition of the fuel/air mixture is not realizable due to low air temperatures [1,[21][22][23][24][25][26].…”