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A detailed chemical kinetic model for the supercritical water oxidation of methylamine: The importance of imine formation
Author(s) -
Ashraful A. M.,
da Silva Gabriel
Publication year - 2020
Publication title -
international journal of chemical kinetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.341
H-Index - 68
eISSN - 1097-4601
pISSN - 0538-8066
DOI - 10.1002/kin.21393
Subject(s) - chemistry , methylamine , supercritical water oxidation , supercritical fluid , imine , formaldehyde , amine gas treating , kinetics , ammonia , reaction mechanism , photochemistry , organic chemistry , catalysis , physics , quantum mechanics
A detailed chemical kinetic model has been developed for supercritical water oxidation (SCWO) of methylamine, CH 3 NH 2 , providing insight into the intermediates and final products formed in this process as well as the dominant reaction pathways. The model was adapted from previous mechanisms, with a revision of the peroxyl radical chemistry to include imine formation, which has recently been identified as the dominant gas‐phase pathway in amine oxidation. The developed model can reproduce previous experimental data on methylamine consumption and major product formation to reasonable accuracy, although with deficiencies in describing the induction time. Our simulations indicate that oxidation of the • CH 2 NH 2 radical to methanimine, CH 2 NH, is the major channel in methylamine SCWO, with subsequent hydrolysis of CH 2 NH providing the experimentally observed reaction products ammonia and formaldehyde. Integral‐averaged reaction rates were used to identify major reaction pathways, and a first‐order sensitivity analysis indicated that the concentration of CH 3 NH 2 is most sensitive to OH radical kinetics. Overall, this work clarifies the importance of imine chemistry in the oxidation of nitrogen‐containing compounds and indicates that they are necessary to model these compounds in SCWO processes.