Experimental study of fuel-lean reburn system for NOX reduction and CO emission in oxygen-enhanced combustion

Abstract

A fuel-lean reburn system is found here to be able to replace a conventional reburning technique in terms of increasing efficiency. In the fuel-lean reburn system, the amount of injected reburn fuel into the reburning zone is low enough to maintain the overall fuel-lean condition in the furnace, so that no additional air system is required, and CO emission can be maintained at almost zero level. In this study, an experimental study has been done to examine the reduction characteristics of NO X in a lab scale combustor (15 kW) with various oxygen-enhanced combustion conditions. Liquefied Petroleum Gas (LPG) was used as a main fuel and reburn fuel. Finally, the current fuel-lean reburn system, even with only an amount of reburn fuel of 13% of total heat input, was observed to achieve a maximum of 48% in NO X reduction.

Low-Emission Combustion of Alternative Solid Fuel in Fluidized Bed Reactor

“…Air excess coefficient λ is defined as quotient of amount of oxygen delivered to reaction zone and amount of oxygen used in combustion processes. For combustion reaction [22] this dependence can be written as:…”

“…Reburningu method since the beginning of its implementation was and still is widely used in the technics [17][18][19][20][21][22][23]. Its main advantages are: the reduction of NOx at a satisfactory level (up to 70% in industrial installations), the economic viability (it is cheaper method compared to SCR), technological simplicity and safety compared to the SCR and SNCR where ammonia is used.…”

“…Other commonly used reburning fuels are gaseous fuels [18,[22][23][24][25][27][28][29]. Studies have shown that by using such reburning fuel, with a suitably selected residence time of the reactants in the combustion chamber in the installation of 350 MW power, it can be achieved the degree of NO conversion of more than 60% [18].…”

Reburning of Animal Waste Based Biomass with Coal for NOx Reduction, Part I: Feedlot Biomass (FB) and Coal:FB Blends

“…A fuel-lean reburn system was developed [21] to replace the conventional reburning technique which operates under slightly rich condition for increasing NO reduction efficiency [2] and to minimize the CO formation. In the above system, the injected reburn fuel is low enough to maintain fuel-lean condition within the furnace.…”