Thermal conductivity enhancement of Al2O3 nanofluids based on the mixtures of aqueous NaCl solution and CH3OH

Abstract

Adding nanoparticles into the base fluids is expected to increase the gas absorption rate of it. In this study, the methanol (CH3OH)-based Al2O3 nanofluids are prepared for application of the CO2 removal system. The suspension stability and thermal characterizations are estimated by the Tyndall effect and by measuring the thermal conductivity of the nanofluids. Arabic gum (AG) is used as a steric stabilizer and NaCl is added to examine the salts effect on the stability and thermal conductivity of it. Increasing NaCl and CH3OH concentrations increases the thermal conductivity enhancement of the nanofluids which was attributed to the high thermal conductivity ratio of the particle and the base fluids. It is found that the thermal conductivity enhancement of the nanofluids increases with increasing the concentrations of NaCl and CH3OH, and the highest value is obtained similar to 634% for 10 wt% NaCl, 40 vol% CH3OH and 0.1 vol% particle concentrations. (C) 2012 Elsevier Ltd. All rights reserved.