2017/09/01 by Yizhuo He, Jianghui Luo, Yangguang Li +4
Chemical Engineering · Engineering · Materials Science · #Advanced Combustion Engine Technologies #Catalytic Processes in Materials Science #Combustion and flame dynamics
paper · doi:10.1021/acs.energyfuels.7b01797
openalex publication_date 2017/09/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/30
The reburning chemistry in oxy-fuel and oxy-steam combustion of methane was investigated both experimentally and numerically. Comparison experiments in O 2 /N 2, O 2 /CO 2, and O 2 /H 2 O atmospheres were performed in a flow reactor at atmospheric pressure with equivalence ratio ranging from fuel-rich to fuel-lean and temperature from 973 to 1773 K. Experimental results showed that compared with N 2 and CO 2 atmospheres NO reduction observed in H 2 O atmosphere is the lowest under fuel-rich and stoichiometric conditions, while it is the highest under fuel-lean conditions. The NO reduction intensity in CO 2 atmosphere lies between N 2 and H 2 O atmosphere under fuel-rich and fuel-lean conditions; however, it is the highest under stoichiometric conditions. A chemical kinetic mechanism, which was hierarchically structured and updated in our previous work, captured the main characteristics and quantity of CO and NO formation satisfactorily even under fuel-lean conditions. According to the analysis from a chemical kinetic point of view, CO 2 and H 2 O exert significant impacts on altering the radical pool structure to OH dominant, subsequently varying the availability of hydrocarbon radical as a reducing agent, which is the primary reason for the different degrees of NO reduction under fuel-rich, stoichiometric, and fuel-lean conditions. In addition, CO 2 and H 2 O also impact the NO reduction by nitrogen-containing radicals. For CO 2 atmosphere, NCO radical always occupies an overwhelmingly dominant position in NO reduction due to HCN → CH 3 CN → CH 2 CN → CN → NCO, and HNCO → NCO channel is amplified substantially. For H 2 O atmosphere, under fuel-rich and stoichiometric conditions, NH 2 and NH radical are dominant due to the enhancement of NCO → HNCO → NH 2 → NH channel. Under fuel-lean conditions, NCO radical is dominant due to the strength of HNCO → NCO channel.