Remarkable enhancement of convective heat transfer with different nanoparticles in N-methyldiethanolamine solution in gas sweetening process

In this work, effective thermal conductivity and convective heat transfer at different Reynolds number of nanofluid containing nanometer-size particles in N-methyldiethanolamine solution is measured. Thermal conductivity and stability of nanostructures in water-based nanofluid, as well as their dependence to temperature and time variation, are of a great concern. These nanofluids consists of 0.1 mass fraction of spherical silica nanoparticles (SiO2), carbon nanofiber (CNF), UiO-66-NH2 MOF, carbon nanotube functionalized with carboxylic acid as ligand (CNT-COOH), MgO nanoparticles, and colloidal silica. These nanofluids mixed with of N-methyldiethanolamine solution and thermal conductivity coefficients were measured. The appropriate result demonstrated the thermal conductivity is highly related to the optimum concentration of nanoparticle in base fluid, velocity, flow rate, and heat flux. It was found that a combination of CNF and SiO2 nanoparticles in a 1:1 ratio with 0.1 wt.% could enhanced thermal conductivity which will induces greater enhancement by combined nanoparticle base amine fluid in heat transfer application. It has been shown increase of Reynolds number at the mass concentration 0.1 wt.% an increase in convective heat transfer coefficient of nanofluid about 13%. These results improve the thermal conductivity properties of solution in amine plants.