ABSORPTION OF H2S INTO AQUEOUS METHYLDIETHANOLAMINE

The absorption of H2S into aqueous methyldiethanolamine (MDEA) was studied experimentally over the temperature range 15 to 35°C and for MDEA concentrations from 10 to 25 wt% using a laminar liquid jet device and a stirred-cell absorber. The contact times ranged from 2 x 10-3 to 1 x 10-2seconds for the jet absorber and from 6 to 38 seconds for the stirred-cell absorber. It was found that the absorption rate data for both devices could be modelled assuming an instantaneous reaction regime for the reaction between H2S and MDEA. The experimental results were interpreted to give an estimate for the diffusion coefficient of MDEA in water. Diffusion coefficient results are consistent for the two apparatuses. A lower bound for the second-order rate constant for the reaction between H2S and MDEA is estimated from the experimental data to be 1.4 × 1010 cm3Ig mole s at 25°C. © 1987, Gordon and Breach Science Publishers S.A.