Experimental and simulation study of a catalytic-membrane integrated system for efficient CO2 stripping

Abstract

Global warming, mainly caused by carbon dioxide (CO₂) emissions, is rapidly becoming a serious concern. The Carbon Capture, Utilization, and Storage (CCUS) process, particularly the amine-based absorption process, is among the most developed industrial processes for capturing CO₂ from anthropogenic and natural sources. However, the energy-intensive nature of the equipment, as well as its high capital cost, inhibits widespread application. A porous hollow fiber membrane contactor (HFMC) is considered a promising technique for solvent regeneration in CO₂ capture applications. Recent research on catalyst-assisted solvent regeneration has also shown that nano catalytic materials can reduce solvent regeneration energy costs while increasing CO₂ desorption. Therefore, a self-fabricated gas-liquid membrane contactor (GLMC) module integrated with catalytically promoted CO₂ desorption to maximize their potential for solvent regeneration is used in this paper. A polytetrafluoroethylene (PTFE) hollow fiber membrane module combined with and without catalytic stripping is tested for CO₂ stripping performance under varying gas-liquid flowrates, temperatures, and initial CO₂ loading concentrations. Increasing the liquid phase temperature and liquid flowrate significantly improved CO₂ stripping, whereas increasing the gas flowrate did not increase stripping flux as much. Adding nanomaterial increased the stripping efficiency of membrane modules from 53 % to 72 % at 80 °C during CO₂ stripping experiments. Catalytically assisted systems exhibited improved stripping efficiency from 48 % to 65 % when liquid flow rates were increased from 20 mL/min to 100 mL/min. A mathematical model for the fabricated module is developed for CO₂ stripping from rich ethanolamine (MEA) solutions and it is simulated using COMSOL. Model predictions align well with experimental data outcomes.