Experimental Evaluation of the Membrane-Assisted Gas Absorption Technique Efficiency Using an Aqueous Solution Of PEG-400 for the Ammonia Capture

Abstract

This work is carried out in order to identify the most effective mode of operation of the membrane-assisted gas absorption setup in the problems of ammonia recovery. The study was conducted to determine the effect of the adsorbent layer thickness on the efficiency of ammonia separation from a binary mixture of NH3/N2, with an ammonia content of 15 vol.%, by the method of membrane-assisted gas absorption. The study used a commercially available elastomeric poly(dimethylsiloxane)poly(diphenylsesquioxane) membrane (LESTOSIL™) as the membrane, and an aqueous solution of PEG-400 was used as the absorbent. The experiment was carried out at seven different thicknesses of the absorbent layer, from 0 (without absorbent) to 6.5 mm, for each of them the separation efficiency value was obtained at a gas flow of 30 ml/min. There is an inversely proportional dependence of the ammonia concentration in the retentate stream on the thickness of the liquid absorbent layer. The highest separation efficiency (4375.48) was achieved with an absorbent layer thickness of 6.5 mm.