EXPERIMENTAL STUDIES OF CO2 ABSORPTION ENHANCEMENT IN WATER-BASED NANOFLUIDS OF CARBON NANOTUBES

Sumin Lu*, Yingchao Zhao, Jing Song, Yongdan Li

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

Abstract

The improvement of CO2 absorption by CNT nanofluids with deionized water as the base fluid was studied experimentally. The reactor used was a stirred thermostatic reactor, operated batchwise. Pure CO2 was employed in all the experiments. The content of CNTs in the nanofluids ranged from 0 to 0.2% (wt). The acidification treatment of CNTs was employed to improve the stability of the nanofluids. The parameters, such as the concentration of CNT nanoparticles in the nanofluids, the stirring speed, the ultrasonic time for CNT nanofluid preparation, the nitration time and the amount of nitric acid for CNT acidification were varied. The results show that, with the increase of CNT concentration, the enhancement factor first increased and then leveled off after a certain value of the CNT concentration. With increasing stirring speed, the enhancement factor in stable functional CNT nanofluids declines monotonously, while in poorly dispersed raw CNT suspensions, it first increased and then reduced. The ultrasonic and nitration times and the amount of nitric acid have optimum values for the CO2 absorption enhancement. The mechanism of the CNT nanofluid enhancement of CO2 absorption is discussed accordingly. The absorption enhancement by the CNT nanofluid should be mainly attributable to convective motion induced by the Brownian motion and the shuttle effect.

Original languageEnglish
Pages (from-to)597-606
Number of pages10
JournalBRAZILIAN JOURNAL OF CHEMICAL ENGINEERING
Volume34
Issue number2
DOIs
Publication statusPublished - 2017
MoE publication typeA1 Journal article-refereed

Keywords

  • Absorption enhancement
  • nanofluids
  • CNT
  • carbon dioxide
  • mass transfer
  • MASS-TRANSFER
  • THERMAL-CONDUCTIVITY
  • DISPERSION BEHAVIOR
  • SIO2 NANOFLUIDS
  • GAS-ABSORPTION
  • NANOPARTICLES
  • PERFORMANCE
  • PARTICLES
  • DIOXIDE
  • ABSORBER

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