Detailed numerical simulations of low-temperature oxidation of NOx by ozone

FUEL

卷:303

Article

Rovira, Marc¹  Engvall, Klas¹  Duwig, Christophe¹ 

[1] KTH Royal Inst Technol, Dept Chem Engn, SE-10044 Stockholm, Sweden

关键词: Ozone oxidation;    Large eddy simulations;    Chemical kinetics;    NOx removal;   

DOI  :  10.1016/j.fuel.2021.121238

来源: Elsevier

【 摘 要 】

Limiting gaseous nitrogen oxide (NOx) emissions is a major global concern due to their harmful effect on human health and the environment. During the past decade, low-temperature oxidation by ozone (O3) has emerged as a promising solution for NOx removal in the transportation and energy generation sectors. In the present study, three-dimensional (3D) large eddy simulations (LES) of the turbulent reacting flow inside a NOx-O3 reactor are performed. It is the first publication using LES and detailed finite rate chemistry for such a reactor. Additionally, plug-flow reactor (PFR) simulations are employed to identify the best performing chemical kinetic mechanisms among those available in the literature over the range of conditions studied. Furthermore, results from different experimental works are reviewed to analyze the variability in the literature. Additionally, this will aid in devising a strategy for validation. Time-averaged results obtained from PFR and combined LES-PFR simulations are observed to agree well with experimental results. The species correlation, distribution, and overall flow uniformity in the pure LES simulations are also assessed and the results highlight the benefits of a high mixing efficiency reactor geometry. Moreover, relevant features of the unsteady flow throughout the present reactor are studied. In particular, the analysis of coherent structures and the existence of regions with non-reacted gases and their relation to mixing and NOx oxidation efficiency are evaluated. The present simulations enable a novel understanding of the interplay between mixing and chemistry and highlight, for the first time, details of the oxidation of NOx by O3.

【 授权许可】

Free