Advanced desulfurization of fuel oil: integrating electromagnetic and hybrid technologies for sustainable processing

Abstract

High sulfur content in fuel oil drives SOx emissions and equipment corrosion, necessitating advanced desulfurization to meet IMO 2020 (0.5 wt%) and USEPA (10–15 ppm) standards. This review critically evaluates six methods – hydrodesulfurization (HDS), oxidative (ODS), adsorptive (ADS), extractive (EDS), biodesulfurization (BDS), and electromagnetic desulfurization (EMDS) – focusing on EMDS–ODS–ADS hybrids for heavy fuels. EMDS uses high-frequency magnetic fields and ferromagnetic nanoparticles for up to 85 % sulfur removal under mild conditions (25–250 °C, 1–5 bar). Hybrids excel in lab-scale tests, yet ODS drops from 100 % (model fuels) to 58.54 % (heavy oil), revealing matrix effects (25–40 % loss). No continuous EMDS-hybrid pilots exist for real heavy crudes. EMDS challenges include nanoparticle aggregation (3–5 cycles), field energy demands, and costs, requiring techno-economic validation. Quantitative analysis of oxidant stoichiometry ( r _ox  = 1.0–3.0), energy-normalized metrics, stability, and biotoxicity shows HDS–ODS as near-term industrials, EMDS-hybrids precommercial. Future roadmap prioritizes recyclable EMDS catalysts, heavy-fuel pilots (1 bbl/d, 18–36 months), and HDS life-cycle comparison – without real-feedstock data, laboratory claims systematically overestimate industrial viability.