Transition metal oxide (NiO, CuO, ZnO)-doped calcium oxide catalysts derived from eggshells for the transesterification of refined waste cooking oil

This paper reports the synthesis of new transition metal oxide-modified CaO catalysts derived from eggshells for the transesterification of refined waste cooking oil. CaO is a well-known base catalyst for transesterification. However, its moderate basicity and low surface area have restricted its catalytic performance. Therefore, a new attempt was made to modify the CaO catalyst with transition metal oxides, including Ni, Cu and Zn oxides, via simple wetness impregnation method. The catalytic performance of the resulting modified CaO-based catalysts was evaluated through the transesterification reaction using refined waste cooking oil. The results showed that the NiO/CaO(10 : 90)(ES) catalyst calcined at 700 °C, demonstrated being highly potential as a catalyst. It gave the highest biodiesel production (97.3%) at the optimum conditions of 1 : 18 oil-to-methanol molar ratio, 6 wt% catalyst loading and 180 minutes reaction time as verified by response surface methodology (RSM). The high catalytic activity of NiO/CaO(10 : 90)(ES)(700 °C) was attributed to its high basicity (8.5867 mmol g⁻¹) and relatively large surface area (7.1 m² g⁻¹). The acid value and free fatty acids of the biodiesel produced under optimal process conditions followed the EN 14214 and ASTM D6751 limit with 0.17 mg KOH per g (AV) and 0.09 mg KOH per g (FFA), respectively.

This paper reports the synthesis of new transition metal oxide-modified CaO catalysts derived from eggshells for the transesterification of refined waste cooking oil.

Catalytic Performance of Bulk and Al2O3-Supported Molybdenum Oxide for the Production of Biodiesel from Oil with High Free Fatty Acids Content

Non-edible vegetable oils are characterized by high contents of free fatty acids (FFAs) that prevent from using the conventional basic catalysts for the production of biodiesel. In this work, solid acid catalysts are used for the simultaneous esterification and transesterification with methanol of the FFAs and triglycerides contained in sunflower oil acidified with oleic acid. Molybdenum oxide (MoO3), which has been seldom considered as a catalyst for the production of biodiesel, was used in bulk and alumina-supported forms. Results showed that bulk MoO3 is very active for both transesterification and esterification reactions, but it suffered from severe molybdenum leaching in the reaction medium. When supported on Al2O3, the MoO3 performance improved in terms of active phase utilization and stability though molybdenum leaching remained significant. The improvement of catalytic performance was ascribed to the establishment of MoO3-Al2O3 interactions that favored the anchorage of molybdenum to the support and the formation of new strong acidic centers, although this effect was offset by a decrease of specific surface area. It is concluded that the development of stable catalysts based on MoO3 offers an attractive route for the valorization of oils with high FFAs content.

A Low-Cost, Well-Designed Catalytic System Derived from Household Waste "Egg Shell": Applications in Organic Transformations

A waste feedstock-derived economical basic alternative catalyst is described in this review. Eggshell is one of the household wastes created in tons of weight daily. Therefore, in order to reduce the environmental pollution-related problems, its use in heterogeneous catalysis can be attributed as a great contribution for the chemical and material science society to carry out several known reactions and for the much-needed energy alternative biodiesel production as low-cost catalytic system. Keeping green chemistry in mind, industrial use of these catalysts may also reduce the use of other traditionally used high-cost chemical catalytic systems.

Study of calcined eggshell as potential catalyst for biodiesel formation using used cooking oil

Eggshells were utilized as a cost effective catalyst to assist in biodiesel formation. Eggshells were calcined using different calcination conditions such as temperature and time. The eggshells underwent calcination under 1000 °C in which calcium carbonate was completely converted into calcium oxide under open air conditions. The calcined eggshell catalyst was characterized by X-ray diffraction (XRD). Then the eggshell derived CaO catalyst was subjected to transesterification of used cooking oil (UCO). The parametrics in the transesterification of used cooking oil such as a methanol to oil ratio, weight of catalyst and reaction temperature were evaluated. The optimum result exhibited a 4:1 methanol to oil ratio, 2wt % catalyst, and a 65 °C reaction temperature within two hours. Pure calcined CaO acted as the control of the experiment that was subject to the most optimum eggshell derived catalyst transesterification conditions. The catalytic activity for both the pure calcined CaO and the calcined eggshell derived catalyst were comparable. The biodiesel formation was identified by gas chromatography mass spectrometry (GC-MS).

Eggshell waste as catalyst: A review

Agricultural wastes are some of the most emerging problems in food industries because of their disposal cost. However, it is also an opportunity for the bioeconomy society if new uses for these residual materials can be found. Eggshells, considered a hazardous waste by UE regulations, are discarded, amounting hundreds of thousands of tonnes worldwide. This egg processing waste is a valuable source material, which can be used in different fields such as fodder or fertilizer production. Additionally, this residue offers interesting characteristics to be used in other applications, like its employment as an environment-friendly catalyst. In the present review we provide a global view of eggshell waste uses as catalyst in different processes. According to reviewed researching works, a huge variety of added value products can be obtained by using this catalyst which emphasised the interest of further investigations in order to widen the possible uses of this cheap green catalyst.