Waste crab shell derived CaO impregnated Na-ZSM-5 as a solid base catalyst for the transesterification of neem oil into biodiesel

Activated calcium oxide extracted from crab shell impregnated on Na-ZSM-5 has been investigated. Crab shells were collected, powdered and calcined at 900 °C, and CaO was impregnated on Na-ZSM-5 and calcined at 550 °C for 10 h. The CaO/Na-ZSM-5 was characterized by X-ray diffraction, scanning electron microscopy and BET surface area. The prepared catalyst was tested for its catalytic activity by transesterifing neem oil into biodiesel in the presence of methanol. The influence of various parameters including reaction time, temperature, methanol to oil ratio, catalyst concentration and dosage were also investigated. Produced biodiesel have also been tested using proton NMR spectroscopy. Biodiesel yield as 95% has been achieved with 15% CaO impregnated on Na-ZSM-5 at 75 °C. The optimum transesterification reaction conditions were identified as follows: reaction temperature, 75 °C; reaction time, 6 h; methanol-to-neem oil molar ratio, 12:1; catalyst dosage, 0.2 g; and catalyst concentration, 15%. Based on the above study, it can be concluded that the calcium oxide impregnated Na-ZSM-5 can be a potential catalyst for biodiesel production.