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The primary objective of this work was to investigate the simultaneous removal of refractory sulfur (dibenzothiophene, DBT) and nitrogen compounds (indole, IND) from model gasoline. This research aimed to develop an efficient adsorption process to mitigate the emission of sulfur oxide and nitrogen oxides, which pose direct threats to human health and the environment. Additionally, the study focused on addressing technical challenges encountered in the refinery process, particularly the poisoning of catalysts due to the presence of these compounds. To achieve the study's goals, granular activated carbon (GAC) was subjected to acid treatment for modification. Molybdenum species were then incorporated into the acid‐treated GAC using the wet impregnation technique. The composition and distribution of elements on the surface of the modified GAC (Mo‐AAC) were analyzed via X‐ray photoelectron spectroscopy (XPS). Various characterization techniques were employed to confirm the uniform dispersion of molybdenum species on the GAC surface. The specific surface area of the adsorbent was increased from 257 m2/g to 316 m2/g following the acid treatment and molybdenum modification. The study explored the impact of several key parameters on the removal of DBT and IND using central composite design (CCD). A regression model was derived using CCD through hybrid central composite design, and its adequacy was verified with the means of tests such as analysis of variance (ANOVA), a lack of fit test, and residuals distribution consideration. Experimental results match well with the results obtained by CCD model, justifying the accuracy of models. The results showed that all four parameters have a significant impact on removal of DBT and IND. Increasing temperature and the adsorbent dose positively affected the removal of both DBT and IND, indicating that higher temperatures and greater adsorbent dosages improved removal efficiency. On the other hand, the concentration of DBT and IND had a negative impact, signifying that higher initial contaminant concentrations hindered removal efficiency. The study determined the optimum initial contaminant concentrations for DBT and IND, temperature, and adsorbent dose to be 186 mg/L, 50 mg/L, 25.5°C, and 32 g/L, respectively. These conditions yielded the highest removal efficiency. The research demonstrated that Mo‐AAC has the capability to effectively reduce the sulfur and nitrogen content of model gasoline, making it a promising solution for addressing environmental and refinery challenges associated with these compounds. [ABSTRACT FROM AUTHOR]

A rice husk‐derived MCM‐41 catalyst has been synthesized, and active metal Co3O4 nanoparticles were incorporated. The synthesized MCM‐41 derived from rice husk exhibited highly ordered p6mm hexagonal symmetry. The catalytic activity of the prepared catalyst was investigated for glycerol carbonate (GLc) synthesis through transesterification of glycerol (GLy) with dimethyl carbonate (DMC). Experimentally, it was found that 5 wt.% cobalt incorporated MCM‐41 activated at 400°C showed a higher yield of GLc, 60.2%, due to its optimum basicity. Approximately, 98.7 ± 1.2% GLy conversion and 94.1 ± 0.7% GLc yield was achieved with the batch reactor at adjusted conditions: a molar ratio of DMC‐to‐glycerol = 3, catalyst dosage = 6 wt.% (based on glycerol mass), reaction temperature = 90°C, and reaction time = 2 h. The transesterification reaction kinetics were also studied using the ODE 15s tool in MATLAB. The catalyst's activation energy was calculated as 58.2 ± 2.4 kJ/mol. [ABSTRACT FROM AUTHOR]

The present study investigates the feasibility of nitrogenous heterocyclic compounds (NHCs) (Pyridine-Quinoline) degradation by catalytic wet peroxidation (CWPO) in the presence of nanoscale zerovalent iron supported on granular activated carbon (nFe0/GAC) using statistical optimization technique. Response surface methodology (RSM) in combination with Box-Behnken design (BBD) was used to optimize the process parameters of CWPO process such as initial pH, catalyst dose, hydrogen peroxide dose, initial concentration of pyridine (Py) and quinolone (Qn) were chosen as the main variables, and total organic carbon (TOC) removal and total Fe leaching were selected as the investigated response. The optimization of process parameters by desirability function showed the ~85% of TOC removal with process condition of initial solution pH 3.5, catalyst dose of 0.55 g/L, hydrogen peroxide concentration of 0.34 mmol, initial concentration of Py 200 mg/L and initial concentration of Qn 200 mg/L. Further, for TOC removal the analysis of variance results of the RSM revealed that all parameter i.e. initial pH, catalyst dose, hydrogen peroxide dose, initial concentration of Py and initial concentration of Qn were highly significant according to the p values (p < 0.05). The quadratic model was found to be the best fit for experimental data. The present study revealed that BBD was reliable and effective for the determination of the optimum conditions for CWPO of NHCs (Py-Qn). [ABSTRACT FROM AUTHOR]

Nano zero-valent iron particles (nZVI) supported on granular activated carbon (GAC) (nZVI/GAC) were synthesized and its feasibility was explored for the treatment of pyridine-bearing wastewater. nZVI/GAC was synthesized by the borohydride reduction method under ethanol atmosphere. The synthesized nZVI/GAC was characterized by scanning electron microscopy (SEM), X-ray diffraction, Fourier transform infrared spectroscopy, and N2adsorption–desorption study. Results indicated that the nZVI was well dispersed on the surface of GAC. The presence of support material apparently decreased the extent of aggregation and size of the nZVI and thus, facilitated in increasing the pyridine removal efficiency. Batch studies were carried out in order to evaluate the effect of operating parameters such as pH (2 ≤ pH ≤ 9), dose (m) (5 ≤ m ≤ 15 g/l), initial concentration (Co) (50 ≤ Co ≤ 1000 mg/l), and temperature (T) (288 ≤ T ≤ 318 K). At optimum condition, maximum removal of pyridine was found to be ~86% atm = 15 g/l, pH = 6,Co = 100 mg/l, andT = 303 K. The degradation kinetics has been investigated, and pseudo-first-order kinetic model was found to be suitable fit for the experimental data kinetic model. The apparent activation energy (Ea) of this process was found to be ~22.46 (kJ/mol). The nZVI/GAC showed stable performance for the degradation of pyridine-bearing wastewater until five consecutive cycles. [ABSTRACT FROM PUBLISHER]