NOxreducering

NOxreducering refers to the set of practices, technologies, and operational strategies aimed at reducing nitrogen oxides (NOx) produced by combustion processes. While not a standard term in all scientific or regulatory contexts, it is used to describe the collective approach to lowering NOx emissions across industries, in line with air quality and climate objectives.

NOx formation is strongly influenced by high flame temperatures and excess oxygen. NOxreducering includes design and operational controls such as staged or lean-burn combustion, low-NOx burners, and exhaust gas recirculation (EGR) to lower peak temperatures and reduce NOx formation during combustion. These measures are often implemented at the source, before NOx is created.

Post-combustion and catalytic methods are another major component. Selective catalytic reduction (SCR) uses a catalyst and a reductant (typically ammonia or urea) to convert NOx into nitrogen and water. Selective non-catalytic reduction (SNCR) achieves NOx reduction through reductant injection at high temperatures without a catalyst. Additional considerations include ammonia slip management and catalyst maintenance.

Applications of NOxreducering span power generation, marine propulsion, cement and chemical kilns, and heavy-duty road and rail vehicles. Regulatory frameworks such as the European Union’s Euro standards and United States EPA emissions tiers drive the adoption of NOx reduction technologies, with monitoring usually performed via continuous emissions monitoring systems (CEMS) and periodic testing.

Challenges include upfront capital costs, energy penalties, maintenance and aging of catalysts, and issues like ammonia slip. Retrofit of existing plants can be complex. Ongoing research in low-temperature SCR, advanced catalysts, hybrid systems, and the use of alternative fuels continues to enhance the effectiveness and efficiency of NOxreducering.