Kinetics and mechanism of the atmospheric oxidation of tertiary amyl methyl ether

Abstract

Tertiary-amyl methyl ether (TAME) is proposed for use as an additive to increase the oxygen content of gasoline as stipulated in the 1990 Clean Air Amendments. The present experiments have been performed to examine the kinetics and mechanisms of the atmospheric removal of TAME. The kinetics of the reaction of OH with TAME was examined by using a relative rate technique in which photolysis of methyl nitrite or nitrous acid was used as the source of OH. The OH rate constant for TAME and two major products (t-amyl formate and methyl acetate) were measured and yields for ten products were determined as primary products from the reaction.Values determined for the rate constants for the reaction with OH were 5.48 X 10-l' (TAME), 1.75 x 10-l' (t-amyl formate), and 3.85 X cm3 molec-1 s-l (methyl acetate) at 298 2 2 K. The primary products (with corrected yields where required) from the OH + TAME that have been observed include (1) t-amyl formate (0.366), methyl acetate (0.349), acetaldehyde (0.43, corrected), acetone (0.036), formaldehyde (0.549), t-amyl alcohol (0.0261, 3-methoxy-3-methyl-butanal (0.044, corrected), t-amyloxy methyl nitrate (0.029), 3-methoxy-3-methyl-2-butyl nitrate (0.010), and 2-methoxy-2-methyl butyl nitrate (0.004). Mechanisms leading to these products involve OH abstraction from each of the four different hydrogen atoms of TAME. 0 1995 John Wiley & Sons, Inc.

Atmospheric chemistry of di-tert-butyl ether: Rates and products of the reactions with chlorine atoms, hydroxyl radicals, and nitrate radicals

“…Previous product studies of ether oxidation in the presence of NO have reported small yields of nitrates (RON02), where these nitrates have been quantified they have yields of the order of 1-3% [21]. The observed 85 % I 1 % yield of tert-butyl acetate shows that the peroxy radicals in Figure 5 react with NO mainly via channel 1Su.…”

The hydroxyl radical reaction rate constants and atmospheric reaction products of three siloxanes

“…This method uses a two step mechanism, the formation of product (MDOH) due to reaction of OH ϩ MM followed by OH ϩ MDOH. This approach, which has been previously described in detail [13,14], yields an expression of the following form:…”

The hydroxyl radical reaction rate constant and products of 3,5‐dimethyl‐1‐hexyn‐3‐ol

“…While several hydroxyl radical (OH) + oxygenated organic bimolecular rate constants are well known, details pertaining to the OH + oxygenated organic compound reaction mechanisms are limited [12,13]. A few recent studies of the products from OH + oxygenated organic reactions have illustrated the complexity of their gas-phase reaction mechanisms [14][15][16][17][18][19][20]. These investigations are needed to support hydroxyl radical reaction mechanism patterns based on chemical structure reactivity relationships [21].…”