Parametric optimization of in-situ heavy oil upgrading using simultaneous microwave radiation and magnetic nanohybrids via Taguchi approach

Abstract

This study investigated the effect of Fe3O4, Fe3O4-MWCNT, and Fe3O4-NiO nanohybrids on the in-situ heavy oil upgrading using microwave radiation through the Taguchi DOE method. The nanohybrids were synthesized via a co-precipitation method and were characterized using different analyses. Three numerical parameters, including the concentration of nanohybrids, power and time of microwave radiation, and a categorical factor including the type of the nanohybrids, were considered in a DOE plan. Results showed that electrical permeability, loss tangent, and electrical conductivity of Fe3O4-MWCNT nanohybrids are higher than other nanoparticles. Nanoparticle’s concentration (at 0.5 wt%) had the most significant effect on reducing the viscosity and increasing the API degree of crude oil. All three system responses, including viscosity, API, and oil sample temperature, were raised by increasing the power of microwaves from 400 W to 1200 W. The lowest viscosity of crude oil was obtained at low irradiation times (8 min.). The optimal conditions for achieving the greatest reduction in crude oil viscosity were a combination of using 0.5 wt% of Fe3O4-MWCNT nanohybrid under 8 min of 400 W microwave radiation. Finally, it found that microwave radiation has made the oil sample lighter and reduced the sulfur content in the crude oil. So, the use of Fe3O4-MWCNT nanohybrid has reduced the sulfur content in the primary crude oil sample by 16.6%.