Experimental investigation and mathematical modeling of CO2 sequestration from CO2/CH4 gaseous mixture using MEA and TEA aqueous absorbents through polypropylene hollow fiber membrane contactor

In the current study, experimental and mathematical results of a counter-current contact between CO2/CH4 gaseous mixture and aqueous liquid absorbents (MEA and TEA) through a microporous polypropylene hollow fiber membrane contactor are presented to evaluate the sequestration percentage of CO2 acidic pollutant from gaseous mixture. One of the aims of this paper is to experimentally and mathematically study the effects of gas flow rate, aqueous liquid absorbents' flow rate and also inlet CO2 concentration on the removal efficiency of CO2. In order to carry out this, a two dimensional mathematical model is developed to predict the experimental results. The experimental results show that MEA absorbent has higher superiority for efficient removal of CO2 acidic gas compared to TEA absorbent. Based on the experimental results, the sequestration efficiency of CO2 from gaseous mixture applying MEA and TEA aqueous absorbents is about 92% and 62%, respectively. The simulated results of CO2 sequestration in wide ranges of gas flow rate, inlet CO2 concentration and liquid absorbents' flow rate demonstrate an excellent agreement with those of experimentally measured ones with average absolute relative errors (AAREs) of 4.3%, 4.4% and 3.6% for employing MEA and 6.9%, 3.4% and 5.2% for using TEA absorbents, respectively. Additionally, this article aims to study the influence of momentous operational parameters such as number of fibers, module length and also membrane porosity and tortuosity on the CO2 separation efficiency. Based on the experimental and the numerical simulated results, increase in the gas flow rate, the membrane tortuosity and the CO2 inlet concentration significantly deteriorates the sequestration efficiency of CO2 while increment of the fibers counts, the membrane module length, the membrane porosity and the liquid flow rate positively encourages the CO2 sequestration percentage.