Simultaneous NOx and Dioxin Removal in the SNCR Process

Abstract

Nitrogen oxides, polychlorinated dibenzo-p-dioxins, and polychlorinated dibenzofurans are pollutants formed during thermal processes, in particular during the combustion of various fuels, including waste. They are classified as dangerous and highly toxic environmental pollutants whose emissions are strictly regulated. Many methods for reducing their emissions are known, but all involve additional production costs. For this reason, effective and cheap methods for removing these pollutants from exhaust gases are still sought. Selective non-catalytic reduction of nitrogen oxides is one of the more effective and cheaper methods for reducing these emissions. However, an alternative to expensive methods for dioxin and furan removal (catalysis, adsorption, etc.) may include using dioxin synthesis inhibitors. The authors propose a method for the simultaneous removal of both pollutants from flue gases using selective non-catalytic reduction technologies with dioxin synthesis inhibitors used as reducing agents.

Bimodal effect of water on V2O5/TiO2 catalysts with different vanadium species in the simultaneous NO reduction and 1,2-dichlorobenzene oxidation

“…NO X are usually abated applying the selective non catalytic reduction (SNCR), because it is relatively simple and cheap [4,5]. In SNCR, NO X are reduced to N 2 in the combustion chamber by injecting ammonia or ammonia precursors, such as urea [4,[6][7][8]. The NO X efficiency in this process is approximately 40-70%, although ammonia excess conditions are necessary [7,9,10].…”

“…In SNCR, NO X are reduced to N 2 in the combustion chamber by injecting ammonia or ammonia precursors, such as urea [4,[6][7][8]. The NO X efficiency in this process is approximately 40-70%, although ammonia excess conditions are necessary [7,9,10]. This fact usually causes an ammonia slip.…”

Estimating the Characteristics and Emission Factor of Ammonia from Sewage Sludge Incinerator

“…In sewage sludge incineration facilities, selective non-catalytic reduction (SNCR) is utilized to reduce the emission of nitrogen oxides (NOx). In the case of SNCR, NOx can be reduced, but if excessively operated, NH 3 will be generated and discharged into the atmosphere [ 5 , 6 , 7 , 8 ]. NH 3 is one of the secondary products of ultrafine particles and is considered to be an odorous air pollutant [ 9 , 10 , 11 ].…”

Reaction Characteristics of NOx and N2O in Selective Non-Catalytic Reduction Using Various Reducing Agents and Additives

“…Although SCR processes are more efficient than SNCR processes [6], the latter offer the benefits of lower installation costs, convenience, and broad applicability, and are therefore more widely used in industry [7]. Given that SNCR has been used as the best available control technology and best available technique in numerous countries [6][7][8], many researchers have attempted to improve its NO x reduction efficiency by altering the reaction conditions, e.g., through the introduction of auxiliary agents and additives [9][10][11].…”