a b s t r a c tIn the present work, Cyrtopleura costata (Angel Wing Shell) is used for the first time to synthesis of CaO. The produced CaO was utilized as a catalyst for biodiesel production from microalgae Nannochloropsis oculata oil. The Angel Wing Shell (AWS) was calcined at 800°C and 900°C for 2 h to convert CaCO 3 to activate metal oxide phase. The synthesized catalysts were characterized by using Thermogravimetric analysis (TGA), X-ray diffraction (XRD), Temperature programmed desorption of CO 2 (CO 2 -TPD), BET surface area and Scanning electron microscopy (SEM) analysis. The calcined Angel Wing Shell at 900°C (CAWS 900) was chosen as the best catalyst due to its high basicity and surface area. This also corresponded to optimization condition where, CAWS 900 showed highest FAME yield (84.11%) at oil to methanol molar ratio 1:150 and catalyst loading of 9 wt.% in 1 h reaction time. The CAWS 900 catalyst also can be reused more than three times with FAME yield greater than 65%. Overall, AWS appears to be an acceptable solid catalyst to convert microalgae oil to biodiesel.

No abstract

In this study, waste venus clam (WVC) was used as a raw materials of catalyst to produce biodiesel from palm oil at atmospheric pressure. The thermogravimetric, surface functional group, morphology, structure, basicity, surface area and leaching properties of catalyst was studied by using TGA, FTIR, SEM, XRD, TPD-CO2, BET, and AAS respectively. The result demonstrated that CS-900 catalyst gave high amount of total basicity at about 44 times than commercial CaO catalyst which is favorable for higher catalytic activity. Further, it was evident from BET that the shells calcined in temperature range 800-900 °C was exhibited enhance surface area than uncalcined shells. Under the best reaction condition (temperature 65 °C, methanol/oil molar ratio 15:1, reaction time 6 h, and catalyst 5 wt.% of oil), a high biodiesel yield of 97% was obtained. The leaching test on synthesized biodiesel revealed that the concentration of Ca in the biodiesel was 1.214 ppm which is inacceptable levels of metals as ASTM D6751 (United State) and in Europe, EN 14214 (Europe) standards. The subsequent reuse of the catalyst indicates the viability of utilizing waste shell as green catalysts for synthesis of biodiesel.

No abstract

In this research, shells of Cyrtopleura costata, commonly known as angel wing, were used to prepare sulfated calcined angel wing shell (CAWS) catalysts by a simple, low-cost method. The produced CAWS-SO 4 catalyst was characterized by using X-ray diffraction (XRD), Fourier transmission infrared spectroscopy (FTIR), temperature programmed desorption of CO 2 and NH 3 (CO 2-TPD and NH 3-TPD), BET surface area analysis and variable pressure scanning electron microscopy (VP-SEM). The esterification of palm fatty acid distillate (PFAD) by supercritical methanol was successfully performed to obtain the high fatty acid methyl esters (FAME) with yield of 98% at the optimum methanol/PFAD molar ratio of 6/1, 2 wt.% catalyst loading, 290 °C in 15 min. The catalyst could also be reused up to seven cycles with a FAME yield higher than 80% in the last cycle. The characterization of spent catalyst has been performed by using XRD, FTIR, TPD-NH 3 and SEM.