Shock tube investigations of methyl tert butyl ether and methyl tetrahydrofuran high-temperature kinetics

The auto ignition and pyrolysis of two C5 ethers, methyl tert butyl ether (MTBE) and methyl tetra hydrofuran (2-MTHF), are investigated using the shock tube reactor. The experiments are carried out at pressures of 3.5 atm and 12 atm at temperatures above 1000 K with argon as a diluent gas. By means of direct laser absorption, carbon monoxide time histories and associated chemical kinetic time scales are also measured. The resulting experimental observations are then compared with predictions of existing chemical kinetic models from the literature. The results point to differences in chemical reactivity, such that in pyrolysis conditions, the reactivity of the cyclic ether, 2-MTHF, is generally higher than that of the aliphatic ether, MTBE. While agreement between experimental observations and model predictions is observed under certain conditions, significant variance between observations and predictions is observed under other conditions. The work aligns with, and contributes to, current efforts in characterizing the combustion properties of oxygenated hydrocarbons.