Natural and synthetic zeolites are well-known materials sharing a wide range of applications, such as adsorbents, ion exchange, and catalysts. However, synthetic zeolites are more widely used, due to several limitations of natural zeolites, such as the presence of impurities and diverse compositions. In this study, rice husk silica (97.86% purity) and aluminum hydroxide were utilized for the preparation of ZSM-5, to study the effect of crystallization time on the physical characteristics and catalytic activity in the transesterification of Ricinus communis oil. The raw materials, with molar ratio of SiO₂:0.025Al₂O₃:0.165Na₂O:25H₂O, were subjected to crystallization at 180 °C for 48, 72, 96, and 120 h, completed by 6 h calcination at 600 °C. The formation of ZSM-5 was demonstrated by FTIR, XRD, and SEM techniques, confirmed that the formation of ZSM-5 had taken place at 48 h crystallization, with no significant change with prolonged time. The PSA indicates the existence of two clusters of particles, and the BET confirmed the existence of the zeolites as porous materials, with the sample prepared with crystallization time of 96 h had the largest surface area and smallest pore diameter. This particular sample exhibited the highest activity, resulting in 96% conversion of Ricinus communis oil.

Oriental Journal of Chemistry is a peer reviewed quarterly research journal of pure and applied chemistry. It publishes standard research papers in almost all thrust areas of current chemistry of academic and commercial importance. It provides a platform for rapid publication of quality research papers, reviews and chemistry letters. Oriental Journal of Chemistry is abstracted and indexed in almost all reputed National and International agencies.

In this study, transesterification of coconut oil with dimethyl carbonate (DMC) for preparing biodiesel has been studied using TiO2/SiO2 as heterogeneous catalyst, with the main purpose to investigate the effect of molar ratio of DMC to oil. The product was analyzed by GC-MS to identify the fatty acid methyl esters (FAMEs) composting the biodiesel. The significant role of the DMC to oil ratio was observed in this study, in which the oil conversion was found to increase with increasing molar ratio of DMC : Oil, with the highest percent of conversion of 88.44%. The GC-MS analysis revealed the presence of methyl esters in accordance with the composition of coconut oil commonly reported. Formation of FAMEs was verified by 1H-NMR spectroscopic analysis, which also suggested that some of the fatty acids remain unconverted into biodiesel. The biodiesel produced was found to have kinematic viscosity of 2.4 mm2/S at 40 °C, flash point of 103 °C, and cetane number of 54.

In this research, transesterification of rubber seed oil (RSO) with methanol in the presence of MgO/zeolite-A composites with different MgO loads as catalysts was investigated. In addition, the effect of different reaction parameters including oil to methanol ratio, the amount of catalyst, and transesterification time were also investigated. Zeolite-A was prepared from rice husk silica (RHS) and food-grade aluminum foil and confirmed using XRD and SEM/EDS techniques. The MgO/zeolite-A composites with different MgO loads were prepared by impregnating the zeolite with Mg (NO3)2 solution of different concentrations. The composites were then characterized using XRF, XRD, and SEM, and finally applied as a catalyst in transesterification of RSO at varied experimental conditions. The XRF results indicated that the zeolite has been successfully impregnated, and the content of MgO varied depending on the concentration of magnesium nitrate solution used for impregnation process. Zeolite-A and also MgO/zeolite-A composites were confirmed by XRD investigations, supported by SEM analysis with indicated the shape of cubic particle, a characteristic feature of zeolite-A, and rod like structure which is most likely the MgO particle. The results of transesterification experiments revealed the appreciable activities of the composites and the effect of reaction parameters on the conversion of the RSO, with the highest conversion of 89 % achieved using 12.5 % catalyst relative to the mass of RSO, with MgO 4.43 %/zeolite-A catalyst, oil to methanol ratio of 1:10, and a transesterification time of 6.0 h. Analysis of the transesterification products using GC-MS confirmed that fatty acids composing the RSO were converted into corresponding methyl esters. HIGHLIGHTS Zeolite A was prepared from rice husk silica and food grade aluminum foil MgO/Zeolite A composites with different MgO load were prepared using impregnation method MgO/Zeolite A composites were used as catalyst for transesterification of rubber seed oil GRAPHICAL ABSTRACT