A comprehensive mechanism for methanol oxidation

Abstract

A comprehensive detailed chemical kinetic mechanism for methanol oxidation has been developed and validated against multiple experimental data sets. The data are from static-reactor, flow-reactor, shock-tube, and laminar-flame experiments, and cover conditions of temperature from pressure from and equivalence ratio from 0.05-633-2050 K, 0.26-20 atm, 2.6. Methanol oxidation is found to be highly sensitive to the kinetics of the hydroperoxyl radical through a chain-branching reaction sequence involving hydrogen peroxide at low temperatures, and a chain-terminating path at high temperatures. The sensitivity persists at unusually high temperatures due to the fast reaction of comparedThe branching ratio ofwas found to be a more important parameter under the higher temperature conditions, H O 2 due to the rate-controlling nature of the branching reaction of the H-atom formed through CH 3 O thermal decomposition.

Experimental and Kinetic Modeling Study of Methanol Ignition and Oxidation at High Pressure

“…These reactions yield hydroxymethyl and methoxy radicals, with the former radical being predominant. As expected [13][14][15], the hydroxymethyl radical mainly react with oxygen (R18), while methoxy undergoes thermal decomposition (R19). However, due to the larger value of k 27 in the present work, compared to previous modeling studies, the reaction of CH 3 O with O 2 (R27) becomes competitive under lean conditions.…”

“…1 indicates that unimolecular decomposition of CH 3 O energetically favors CH 2 O formation over isomerization to CH 2 OH. In fact the isomerization also has a rather tight TS, with an A factor at 800 K and the high-pressure limit of 2.4x10 13 Presently, we are not certain about the source of this discrepancy. It may partly be attributed to the fact that they neglected tunneling.…”

“…Laboratory experiments allow more controlled conditions compared to tests in engines; methanol oxidation has been studied in flames [6][7][8], stirred reactors [9], static reactors [10,11], flow reactors [12][13][14][15], Rapid Compression Machines [16], and shock tubes [17]. Of these studies, only three have been carried out at elevated pressures, i.e.…”

“…Of these studies, only three have been carried out at elevated pressures, i.e. 10 bar [9], 20 bar [13] and 30 bar [16], respectively. The aim of the present work is to investigate methanol oxidation at even higher pressures, which are of interest for combustion devices such as diesel engines.…”

Ab initio and kinetic modeling studies of formic acid oxidation

“…of oxygenated hydrocarbons such as methanol [6] and DME [7]. The detection of carboxylic acid emissions from engines has prompted interest in the combustion chemistry of these components and their formation in laminar premixed hydrocarbon flames has been investigated both experimentally [8] and in terms of chemical kinetic modeling [9].…”