Numerical simulation of NOx reduction using low-oxygen combustion and optimization in a TTF precalciner

This paper describes the use of low-oxygen combustion technology to reduce NOx emissions in cement production. Numerical simulation was also employed to simulate the pulverized coal combustion, calcium carbonate decomposition and NOx reduction process in the precalciner of a 5000 t/d clinker cement production line. The simulation gave a temperature at the precalciner outlet of 1260 K, a CO2 mass fraction of 28%, an O2 concentration of 1.2% and an NOx concentration of 523 ppm. The data were in good agreement with the actual measurements. The low-oxygen combustion technology was also optimized by changing the oxygen content in the kiln exhaust gas in order to achieve the best conditions. The results showed that the NOx concentration at the outlet of the precalciner would be lowest (468 ppm) when the oxygen content in the kiln exhaust gas was 3%.

1 Introduction

The cement industry is the third largest source of nitrogen oxides after the power industry and motor vehicles, and China‘s cement production accounts for 65% of global cement production. The problem of the resultant pollutant emissions is also a concern for society. The greatest possible reduction of NOx emissions while at the same time ensuring the economic benefits of cement plants has therefore become a major issue. Many scholars at home and abroad have carried out a great deal of research into this problem. Zhao [1] studied the influence of different amounts and locations...

Related articles:

Issue 2018-4 WO2018025482 (A1)

Method for operating cement kiln

(22) 31.05.2017 (43) 08.02.2018 (57) [Problem] To reduce the concentration of both SOx and NOx in combustion gas discharged from a cement kiln. [Solution] A method for operating a cement kiln 7,...

Issue 2020-11-12 US 2020/0271316 A1

Apparatus for recycling fly ash having quantum energy generator

(22) 22.02.2020 (43) 27.08.2020 (57) An apparatus for recycling fly ash has a quantum energy generator therein. The apparatus recycles fly ash generated as the combustion waste from the burning of...

Issue 2015-11 WO 2015/133161 A1

Cement burning apparatus, and method for denitrating exhaust gas from cement kiln

(22) 08.01.2015 (43) 11.09.2015 (57) [Problem] To efficiently reduce the concentration of NOx in an exhaust gas from a cement kiln while keeping the burned state at a good level regardless of the type...

Issue 2021-3 US 2021/0060478 A1

Carbon capture system comprising a gas turbine

(22) 09.03.2018 (43) 04.03.2021 (57) A method and a plant for capturing CO2 from an incoming flue gas. The flue gas can be exhaust gas from coal and gas fired power plants, cement factories or...

Issue 2021-1 WO 2020/216289 A1

Lime kiln and heat supply method thereof

(22) 23.04.2020 (43) 29.10.2020 (57) Provided are a lime kiln and heat supply method thereof, said lime kiln containing a kiln chamber (1), a heating device, and a combustion-supporting fan (2); the...