A reactive molecular dynamics study of NO removal by nitrogen-containing species in coal pyrolysis gas

Coal splitting and staging is a promising technology to reduce nitrogen oxides (NOx) emissions from coal combustion through transforming nitrogenous pollutants into environmentally friendly gasses such as nitrogen (N 2 ). During this process, the nitrogenous species in pyrolysis gas play a dominant role in NOx reduction. In this research, a series of reactive force field (ReaxFF) molecular dynamics (MD) simulations are conducted to investigate the fundamental reaction mechanisms of NO removal by nitrogen-containing species (HCN and NH 3 ) in coal pyrolysis gas under various temperatures. The effects of temperature on the process and mechanisms of NO consumption and N 2 formation are illustrated during NO reduction with HCN and NH 3 , respectively. Additionally, we compare the performance of NO reduction by HCN and NH 3 and propose control strategies for the pyrolysis and reburn processes. The study provides new insights into the mechanisms of the NO reduction with nitrogen-containing species in coal pyrolysis gas, which may help optimize the operating parameters of the splitting and staging processes to decrease NOx emissions during & COPY; 2022 The Author(s). Published by Elsevier Inc. on behalf of The Combustion Institute. This is an open access article under the CC BY license ( http://creativecommons.org/licenses/by/4.0/ )

Automated summary

Coal splitting and staging is a promising technology for reducing NOx emissions from coal combustion. In this study, molecular dynamics simulations were conducted to investigate the reaction mechanisms of NO removal by nitrogen-containing species (HCN and NH 3 ) in coal pyrolysis gas. The effects of temperature on NO consumption and N 2 formation were analyzed, and control strategies for the pyrolysis and reburn processes were proposed. This research provides new insights into the mechanisms of NO reduction and can help optimize the operating parameters to decrease NOx emissions.