Producing an eco-friendly fuel with the least amount of sulfur compounds has been an ongoing issue for petroleum refineries. In this study, bentonite (which is a cheap material and is locally available in abundance) is employed to prepare a nano-silica catalyst with a high surface area to be used for the oxidative desulfurization of kerosene. Two composite catalysts of Fe/silica were supported on CAT-1 (0% HY-zeolite and 100% nano-silica) and CAT-2 (20% HY-zeolite and 80% nano-silica). The activity of the catalysts was evaluated in a batch ODS (oxidative desulfurization) process at temperatures of 30, 60, 90, and 120 °C, a pressure of 1 atm, and a reaction time of 30, 60, 90, and 120 min using 120 L/h of air as the oxidant. The results revealed that the highest total sulfur removal efficiency was 50% and 87.88% for 100% nano-silica (CAT-1) and 80% nano-silica (CAT-2), respectively. The experimental data were then used to construct and validate an accurate mathematical model of the process. The operational parameters for eliminating more than 99% of sulfur and producing eco-friendly fuel were then achieved by using the model. The testing methods for these characterizing materials included X-ray diffraction (XRD), thermal gravimetric examination (TGA), X-ray fluorescence (XRF), and surface area (BET). The outcomes indicated that the addition of HY-zeolite increased the activity of the catalyst (CAT-2 > CAT-1).

Removal of phenol and phenolic compounds from wastewater using various techniques has received considerable attention in recent years. In this work, the removal of phenol from a model solution of phenol via catalytic oxidation is investigated with oxidant H₂O₂. For this purpose, we designed a new nano-catalyst (8% Fe₂O₃/AC) by loading iron oxide nanoparticles over nano-activated carbon via the impregnation process. We modified the recently developed digital basket baffle batch reactor (DBBBR) and used it for the catalytic oxidation process in order to examine the activity of the prepared nano-catalyst. The highest efficiency of phenol removal was found to be 95.35% under the following parameters: oxidation time of 120 min, oxidation temperature at 85 °C, and stirrer speed of 600 rpm. The minimization of the sum of the squared error between the experimental data and predicted results of phenol removal was considered as a base for the optimization technique to estimate the optimal parameters for the kinetic process. The predicted conversion of phenol excellently agreed with the experimental results (absolute average errors < 5%) for a wide range of process parameters.

Achieving ultra-low-sulfur diesel is a crucial objective in modern fuel refining, driven by increasingly stringent environmental regulations. This study presents the development of a highly efficient oxidative–adsorptive desulfurization process utilizing a nanocatalyst synthesized from biowaste eggshell-extracted calcite. The oxidation reaction was conducted in a digital basket reactor (DBR), an advanced reactor system designed to enhance mass transfer and catalytic efficiency. To further augment the catalyst’s performance, the calcite was modified with eco-friendly MnO₂, while activated carbon was employed as an adsorbent to effectively capture oxidized sulfur compounds, ensuring compliance with ultra-low-sulfur fuel standards. The synthesized nanocatalyst underwent comprehensive physicochemical characterization using SEM, EDX, BET, and FTIR, confirming its high surface area, structural integrity, and superior catalytic activity. The MnO₂/P–calcite catalyst achieved a sulfur removal efficiency of 96.5% at 90 °C, 80 min, and 600 rpm, demonstrating excellent oxidative–adsorptive performance for real diesel fuel. The integration of this innovative nanocatalyst with the DBR system presents a sustainable, cost-effective, and industrially viable approach for deep desulfurization, offering significant advancements in clean fuel production and environmental sustainability.

To maintain a healthy environment and way of life in the modern world, clean fuel must be produced. It is important to totally and successfully remove sulfur-containing harmful compounds from fuel oil in order to comply with the new sulfur legislation. Numerous methods have been proposed in the literature for desulfurizing fuel oil. In this study, activated carbon (AC), which is regarded as a significant porous material, is derived from agro-wastes such as apricot shells (AS) and is loaded with different combinations of active metals. Nickel–Cobalt–Manganese (NCM) over AC is firstly prepared and evaluated experimentally. Then, several concentrations of Molybdenum (1%, 2% and 3%) are separately added to NCM to generate three novel composite mesoporous nano-catalysts (NCMM_1, NCMM_2 and NCMM_3). Several tests have been carried out to determine the catalysts’ properties, such as BET_{surface area}, pore volume, FTIR, TGA and SEM, XRF and XRD. These catalysts are then used in the batch oxidative desulfurization process to remove sulfur compounds from wide cut oil (from IBP to 345 °C). The pilot plant conditions were as follows: air flow rate = 120 L/h, reaction temperature = 363 K and reaction time of 1 h for all catalysts. Remarkable characteristics have been noticed, and it was discovered that the nano-catalyst NCMM_2 performed better in terms of degree of sulfur removal compared to other nano-catalysts.

In the present study, a kinetic model was developed for the process of oxidative desulfurization of light gas oil with 7329 ppm sulfur using a newly synthesized nanocomposite catalyst. The batch reactor experiments were conducted at different thermal conditions (313–373 K) and reaction times (30–90 min) to explain this endeavor of desulfurization performance as a function of these variables, targeting the design of a reliable reactor system. Carbon nanofibers (CNFs) were integrated into the support γ-Al₂O₃ at various concentrations of 5%, 7.5%, and 10% to improve mechanical properties, surface area, and distribution of active metals. The nanocomposite support was impregnated with molybdenum trioxide (MoO₃) and iron oxide (Fe₂O₃) to form four variants of the catalyst: CAT-1 with 10% MoO₃ + 5% Fe₂O₃/Al₂O₃ + 5% CNF, CAT-2 with 10% MoO₃ + 5% Fe₂O₃/Al₂O₃ + 7.5% CNF, CAT-3 with 10% MoO₃ + 5% Fe₂O₃/Al₂O₃ + 10% CNF, and CAT-4 with 10% MoO₃ + 5% Fe₂O₃/Al₂O₃ with no CNF. CAT-3 had the best effectiveness for sulfur removal with 87.5% at 373 K and a reaction time of 90 min. The model predicts a maximum sulfur removal rate of 99.86% under optimal conditions of 550 K and 200 min (for an initial sulfur concentration of 7329 ppm). The experimental and modeling results therefore indicate the potential of the developed catalyst system, while the optimum condition at 550 K and 200 min should be interpreted as a model-predicted outcome. The development of such highly efficient nanocatalysts for deep desulfurization is a crucial advancement in green chemistry, directly contributing to the production of cleaner fuels to mitigate air pollution and supporting the aims of the United Nations Sustainable Development Goals (SDGs), particularly SDG 9 (Industry, Innovation, and Infrastructure) and SDG 12 (Responsible Consumption and Production). From a sustainability perspective, the proposed ODS system supports cleaner fuel production and reduced sulfur-derived emissions, while operating-condition optimization helps improve process efficiency in support of more sustainable refining strategies.

The production of clean fuel with stringent limits on harmful contaminants is one of the petroleum refinery industry’s main goals for improving environmental conditions and being eco-friendly. Iron oxide (Fe₂O₃) loading over composite support (γ-Al₂O₃–TiO₂) was synthesized and evaluated for oxidative desulfurization (ODS) via the incipient wetness impregnation (IWI) procedure. To prolong the lifetime of the nanocatalyst, it was coated with a newly developed manganese compound via IWI technology to suppress substantial deactivation. The composite support, uncoated nanocatalyst, and coated nanocatalyst were tested by different methods of characterization: BET, XRD, FT-IR, FESEM-EDX, mapping, and TEM. The XRD and FTIR results indicated that the composite nanosupport was designed successfully. The FESEM-EDX results indicated high Fe₂O₃ dispersions on the composite nanosupport, and the TEM result represented a good layer of Mn-coated material over the nanocatalyst. The ODS in a newly oscillatory helical baffled reactor (OHBR pilot plant) is utilized to test the performance of the prepared nanocatalysts. Oxidative desulfurization utilized peracetic acid as an oxidant and moderate operating conditions. From the experimental results, it was observed that the optimal desulfurization was 98.42% in the best conditions (amplitude of oscillation = 8 mm, frequency of oscillation = 2 Hz, and oxidation time = 9 min) with an uncoated nanocatalyst. With the coated nanocatalyst, the optimal removal was 96.57% under the same conditions. The uncoated nanocatalyst exhibited good reusability, with sulfur removal decreasing from 98.42% to 87.23% after five consecutive cycles.