Gaseous Diffusion Coefficients of Dimethyl Ether and Diethyl Ether into Air, Nitrogen and Oxygen

Abstract

The gaseous diffusion coefficients of dimethyl ether (CH₃OCH₃, DME) and diethyl ether (C₂H₅OC₂H₅, DEE) into air, nitrogen and oxygen have been measured in the temperature range 303∼453 K and at atmospheric pressure by the use of the Taylor dispersion method. Both for DME and DEE, the diffusion coefficients do not vary in practice on substituting pure nitrogen or oxygen for air. The diffusion coefficients for DEE are systematically smaller than those for DME by about 35%. The present results can be reproduced well by the functional form D/cm²s^-1 = A (T/K)^B, where D is the diffusion coefficient at 101.325 kPa (1 atm) and T is the absolute temperature. The constants A and B are as follows: DME- (air, nitrogen, oxygen), A = 6.61×10^-6, B = 1.75; DEE- (air, nitrogen, oxygen), A = 3.56×10^-6, B = 1.78.