Sound Absorption and Velocity in H2S and CO2/H2S Mixtures

Abstract

Sound velocity and absorption measurements have been made in pure H2S at 300°K and in CO2/H2S mixtures at 300° and 500°K. The results of the measurements on pure H2S indicate no observable relaxation taking place at frequency-to-pressure ratios less than 1200 kHz/atm. The measurements on CO2/H2S mixtures showed the CO2 absorption peak to be shifted to higher frequency-to-pressure ratios by the added H2S at rates of 61.8 and 64.8 kHz per percent H2S at 300° and 500°K, respectively. From this, the relaxation times for the bending vibration of a CO2 molecule in 1 atm of H2S are calculated to be 3.16 × 10−8 and 2.97 × 10−8 sec at the two temperatures. These values are in order-of-magnitude agreement with values calculated on the assumption that the CO2 vibrational energy is exchanged with the rotational energy of the H2S molecule in the relaxation process.