Synthesis of a reusable novel catalyst ( β-tricalcium phosphate) for biodiesel production from a common Indian tribal feedstock

Abstract

In recent times, the rate of energy consumption goes on increasing and the world is desperately searchingfor new sources of fuel. Biodiesel (fatty acid methyl esters) is an alternative renewable energy resourcefor the next generation. Biodiesel has several advantages which include its non-toxic nature, itis biodegradable and it reduces greenhouse gas emissions. β-Tricalcium phosphate ( β-Ca 3 (PO 4 ) 2 ) catalystwas synthesized from fish waste. Fish waste contains calcium phosphate which is converted intoβ-tricalcium phosphate since it has low crystallinity and hydroxyl (OH) groups which decrease the potentialto be a good catalyst for the synthesis of biodiesel through transesterification. This paper exploresthe synthesis of biodiesel using β-tricalcium phosphate ( β-Ca 3 (PO 4 ) 2 ) as a heterogeneous catalyst.Pongamia pinnata (Karanja) oil was extracted from seeds through the solvent extraction process. Intendedfor the development of easier transesterification process, stable and active heterogeneous β-tricalciumphosphate ( β-Ca 3 (PO 4 ) 2 ) catalyst was synthesized and used for the P. pinnata (Karanja) oil transesterificationprocess. The synthesized heterogeneous catalyst was characterized by XRD, FT-IR, SEM and EDX todetermine its structural and morphological characteristics. The catalyst exhibited good catalytic activityon reuse. Biodiesel yield was greatly dependent on operating parameters such as catalyst concentration,methanol to oil molar ratio, reaction temperature and reaction time. Effect of co-solvent on biodiesel wasstudied by using different co-solvents in transestrification reactions. High quality and maximum biodieselyield (97 %) was obtained under the optimized reaction conditions (methanol to oil molar ratio, 10:1(tetrahydrofuran (THF):methanol 1:1); reaction time 90 min; catalyst concentration 2.5 wt % and stirrerspeed 650 rpm at 65 °C). Reusability of catalyst was examined up to five runs and found the catalyst wasreusable up to five times without much loss of catalytic activity.