TY - JOUR
T1 - Soot production in high pressure inverse diffusion flames with enriched oxygen in the oxidizer stream
AU - Liu, Peng
AU - Chu, Carson
AU - Alsheikh, Ibrahim
AU - Gubba, Sreenivasa R.
AU - Saxena, Saumitra
AU - Chatakonda, Obulesu
AU - Kloosterman, Jeffrey W.
AU - Liu, Fengshan
AU - Roberts, William L.
N1 - Funding Information:
Computations were performed on the Niagara supercomputer at the SciNet HPC Consortium. SciNet is funded by: the Canada Foundation for Innovation; the Government of Ontario; Ontario Research Fund - Research Excellence; and the University of Toronto.
Funding Information:
Experiments were supported by funding from the Clean Combustion Research Center (CCRC) of King Abdullah University of Science and Technology (KAUST), KAUST, and Air Products and Chemicals, Inc (RGC/3/4490-01-01).
Publisher Copyright:
© 2022 The Combustion Institute
PY - 2022/11
Y1 - 2022/11
N2 - Catalyst degradation due to soot formation is one of the main issues in the autothermal reforming (ATR) process, which is widely regarded as the future technology for hydrogen production from natural gas. In this work, soot formation under conditions similar to ATR was systematically investigated, focusing specifically on the effects of pressure on soot formation in inverse diffusion flames (IDFs) under oxygen rich conditions. Methane was diluted with carbon dioxide; the oxygen content in the oxidizer stream varied from 55 to 70%-by-mol. Polycyclic aromatic hydrocarbon (PAH) and soot concentrations in the flames were measured by laser-induced fluorescence (LIF) and laser-induced incandescence (LII) respectively. Flame images showed that, as the pressure increased, the luminous region of the IDFs moved downward to mask the blue reaction region, and the flames became narrower. The degree of flame narrowing in the IDFs was milder than normal diffusion flames (NDFs). LIF measurements showed that increasing the pressure promoted PAH formation, which also subsequently promoted soot formation. Both PAH and soot formation increased linearly with pressure. The linear relationship was different from that of the NDFs. Flame simulations suggested that the promotion of soot formation with pressure was largely driven by PAH adsorption. Under the conditions of this study, lowering the oxygen content promotes soot formation in the IDFs. The results of this work contribute to the understanding of soot formation in IDFs at elevated pressures and the optimization of the ATR process.
AB - Catalyst degradation due to soot formation is one of the main issues in the autothermal reforming (ATR) process, which is widely regarded as the future technology for hydrogen production from natural gas. In this work, soot formation under conditions similar to ATR was systematically investigated, focusing specifically on the effects of pressure on soot formation in inverse diffusion flames (IDFs) under oxygen rich conditions. Methane was diluted with carbon dioxide; the oxygen content in the oxidizer stream varied from 55 to 70%-by-mol. Polycyclic aromatic hydrocarbon (PAH) and soot concentrations in the flames were measured by laser-induced fluorescence (LIF) and laser-induced incandescence (LII) respectively. Flame images showed that, as the pressure increased, the luminous region of the IDFs moved downward to mask the blue reaction region, and the flames became narrower. The degree of flame narrowing in the IDFs was milder than normal diffusion flames (NDFs). LIF measurements showed that increasing the pressure promoted PAH formation, which also subsequently promoted soot formation. Both PAH and soot formation increased linearly with pressure. The linear relationship was different from that of the NDFs. Flame simulations suggested that the promotion of soot formation with pressure was largely driven by PAH adsorption. Under the conditions of this study, lowering the oxygen content promotes soot formation in the IDFs. The results of this work contribute to the understanding of soot formation in IDFs at elevated pressures and the optimization of the ATR process.
KW - Autothermal reforming
KW - High pressure combustion
KW - Hydrogen production
KW - Inverse diffusion flame
KW - Soot formation
UR - http://www.scopus.com/inward/record.url?scp=85138808502&partnerID=8YFLogxK
U2 - 10.1016/j.combustflame.2022.112378
DO - 10.1016/j.combustflame.2022.112378
M3 - Article
AN - SCOPUS:85138808502
SN - 0010-2180
VL - 245
JO - Combustion and Flame
JF - Combustion and Flame
M1 - 112378
ER -