Adsorptive Desulfurization of Diesel Fuel Using Copper-Loaded Zeolite Adsorbents at Ambient Conditions

Abstract

Sulfur compounds present in diesel fuel contribute significantly to atmospheric pollution, catalyst poisoning, and acid rain formation during fuel combustion, necessitating the development of efficient desulfurization technologies under environmentally sustainable conditions. The present study investigates the adsorptive desulfurization of diesel fuel using copper-loaded zeolite adsorbents at ambient operating conditions. The research focuses on evaluating sulfur removal efficiency, adsorption capacity, selectivity, and operational stability associated with copper-modified zeolitic adsorbent systems. Experimental analysis was conducted to examine the influence of copper loading, zeolite pore structure, contact time, adsorbent dosage, fuel composition, and sulfur concentration on desulfurization performance and adsorption behavior. Results demonstrate that copper-loaded zeolite adsorbents effectively remove sulfur-containing compounds through π-complexation, chemisorption, and surface interaction mechanisms, resulting in substantial reduction of sulfur content in treated diesel fuel. The study further reveals that optimized copper incorporation and appropriate zeolite structural characteristics significantly enhance adsorption efficiency and improve selectivity toward refractory sulfur compounds such as thiophenes and dibenzothiophenes. Increased adsorbent surface area and controlled operating conditions contributed to improved sulfur uptake and stable adsorption performance under ambient conditions. Comparative assessment with conventional hydrodesulfurization technologies confirms the advantages of adsorptive desulfurization, including lower energy requirements, milder operating conditions, and reduced hydrogen consumption. In addition, the regeneration capability of copper-loaded zeolite adsorbents supports repeated operational use and improved process sustainability.