Influence of non-wetting, partial wetting and complete wetting modes of operation on hydrogen sulfide removal utilizing monoethanolamine absorbent in hollow fiber membrane contactor

Abstract

Hydrogen sulfide is a highly poisonous acidic gas which is regarded as one of the major causes of corrosion and odorous problems. For this reason, the efficient separation of hydrogen sulfide from various gaseous streams is mandatory. This paper aims to evaluate the removal of hydrogen sulfide pollutant from hydrogen sulfide/methane gaseous flow using monoethanolamine liquid absorbent inside the hollow fiber membrane contactor. As the novelty, a mechanistic modelling and a two dimensional numerical simulation are developed under non-wetting (0% wetting of membrane pores), partial wetting (50% wetting of membrane pores) and complete wetting (100% wetting of membrane pores) modes of operation to predict the effects of various operational parameters such as module length, tortuosity and porosity of membrane, initial concentrations of hydrogen sulfide and monoethanolamine on the removal of hydrogen sulfide. The results of mechanistic model prediction under non-wetting mode are in an excellent agreement with the experimental data with average absolute relative error less than 5%. On the basis of the results, monoethanolamine provides the highest hydrogen sulfide sequestration while being used under non-wetting mode of operation in comparison with partial wetting and complete wetting conditions. Membrane pore wettability has a detrimental influence on the removal efficiency of hydrogen sulfide due to creating a considerable mass transfer resistance along the way of hydrogen sulfide gas transport inside the membrane contactor.

Keywords

• Hydrogen sulfide sequestration
• Gaseous stream
• Model prediction
• Wettability