ATMOSPHERIC CHEMISTRY OF AUTOMOTIVE FUEL ADDITIVES - DIISOPROPYL ETHER

To quantify the atmospheric reactivity of diisopropyl ether (DIPE), we have conducted a study of the kinetics and mechanism of reaction 1: OH + DIPE - products. Kinetic measurements of reaction 1 were made using both relative (at 295 K) and absolute techniques (over the temperature range 240-440 K). Rate data from both techniques can be represented by the following: k1 = (2.2(-0.8)+1.4 X 10(-12) exp[(445 +/- 145)/T] cm3 molecule-1. At 298 K, k1 = 9.8 X 10(-12) cm3 molecule-1 s-1. The products of the simulated atmospheric oxidation of DIPE were identified using FT-IR spectroscopy, isopropyl acetate and HCHO were the main products. The atmospheric oxidation of DIPE can be represented by i-C3H7O-i-C3H7 + OH + 2NO --> HCHO + i-C3H7OC(O)CH3 + HO2 + 2NO2. Our kinetic and mechanistic data were incorporated into a 1-day simulation of atmospheric chemistry to quantify the relative incremental reactivity of DIPE. Results are compared with other oxygenated fuel additives.