Permeability and Stability of Hydrophobic Tubular Ceramic Membrane Contactor for CO2 Desorption from MEA Solution

Ceramic membrane contactors hold great promise for CO2desorption due to their high mass transfer area as well as the favorable characteristics of ceramic materials to resist harsh operating conditions. In this work, a hydrophobic tubular asymmetric alpha-alumina (α-Al2O3) membrane was prepared by grafting a hexadecyltrimethoxysilane ethanol solution. The hydrophobicity and permeability of the membrane were evaluated in terms of water contact angle and nitrogen (N2) flux. The hydrophobic membrane had a water contact angle of ~132° and N2flux of 0.967 × 10−5mol/(m2∙s∙Pa). CO2desorption from the aqueous monoethanolamine (MEA) solution was conducted through the hydrophobic tubular ceramic membrane contactor. The effects of operating conditions, such as CO2loading, liquid flow rate, liquid temperature and permeate side pressure, on CO2desorption flux were investigated. Moreover, the stability of the membrane was evaluated after the immersion of the ceramic membrane in an MEA solution at 373 K for 30 days. It was found that the hydrophobic α-Al2O3membrane had good stability for CO2desorption from the MEA solution, resulting in a <10% reduction of N2flux compared to the membrane without MEA immersion.Keywords:membrane contactor;carbon dioxide;desorption;ceramic membrane