CFD simulation of CO2 absorption by water-based TiO2 nanoparticles in a high pressure stirred vessel

Abstract

This work presents the modeling and simulation of CO2 capture by a water-based Titanium dioxide (TiO2) solid nanoparticle in a stirred high-pressure vessel at a constant temperature. Photocatalytic material such as TiO2 has excellent properties, namely it is nontoxic, inexpensive, and non-polluting. CFD model equations are developed and solved using COMSOL software package. The effect of the concentration of a solid nanoparticle in a water-based TiO2 solution, the size of TiO2 nanoparticles and the rate of mixing on the CO2 absorption rate is investigated. A 2D mathematical model considers both shuttle and micro-convention mechanisms. Results reveal that the best TiO2 concentration range is between 0.5 and 1 kg/m3 and that a particle size of 10 nm is more efficient than higher particle sizes. A moderate mixing rate maximizes the CO2 removal rate. The theoretical predictions are validated using lab experimental data and those in the available literature. Results confirm that the model calculations match with the experimental results. Accordingly, the model successfully predicts the experimental data and can be used for further studies.

Review and Perspectives of CO2 Absorption by Water- and Amine-Based Nanofluids

“…Apart from various base liquid types affecting the absorption of CO 2 ions, another primary factor in assessing the capacity of the absorption of CO 2 is nanoparticle types. The nanoparticles that currently apply for CO 2 absorption are CNT, SiO 2 , exfoliated graphene oxide (EGO), Cu, Al 2 O 3 , ZnO, MgO, TiO 2 , CuO, Fe 3 O 4 , Fe 2 O 3 , MgO, ZrO 2 , and modified nanoparticle. ,,,− CNT can be divided into sMWCNT and nMWCNT, and it is generally believed that the nMWCNT is more effective in CO 2 absorption. Rahimi et al prepared concentrated acid and amine-functionalized MWCNT, respectively.…”

“…Ghasem pointed out that there is a solid load limit in the simulation of CO 2 adsorption by TiO 2 nanoparticles. At low concentrations (<0.005 wt %), nanoparticles could enhance mass transfer, but at high concentrations (0.005–1 wt %), the free movement space between particles decreases, inhibiting gas absorption.…”

“…The impact of the pressure on mass transfer efficiency was not discussed intensively until the past decade . Ghasem and Nabipour et al found that increasing the pressure would increase the solubility of CO 2 , which enhanced the absorption effect of CO 2 . In high-pressure systems, amine solutions had replaced the former water, because the poor CO 2 absorption of water also leads to heavier pump loads .…”

Numerical research on biomass wastewater treatment using double-partition vessel with off-centered impellers

“…Studies on the performance prediction of stirred vessels have been carried out since the 1980s. In recent years, computational fluid dynamics (CFD) has also become a very powerful tool in the design of stirred vessels, due to the fact that it can provide detailed information on the turbulent flow field in stirred vessels for singlephase and multi-phase applications [12][13][14][15] . Furthermore, CFD can perform the visualization analysis of the flow field of the semiclosed and closed pilot reactor [16] .…”

Modeling and Simulation of the Impact of Feed Gas Perturbation on CO2 Removal in a Polymeric Hollow Fiber Membrane

“…Membrane contactors are also used for purposes other than absorption. Membrane contactors have been used to strip dissolved gases other than CO 2, such as methane from wastewater treatment anaerobic effluents, natural gas, and flue gas [8,9]. The treatment method has been used in converting chemical oxygen to biogas.…”