Biodiesel production from crude Jatropha Curcas oil using calcium based mixed oxide catalysts Siow Hwa Teo a,b , Umer Rashid c , Yun Hin Taufiq-Yap a,b,c,d,⇑ a Catalysis Science and Technology Research Centre, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia b Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia c Institute of Advanced Technology, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia d Curtin Sarawak Research Institute, Curtin University, Miri, Sarawak, Malaysia highlights  Fatty acid methyl esters were synthesis from crude Jatropha curcas oil (JCO).  The catalytic activity was based on basic sites of binary system of mixed metal oxide.  The FAME yields of >80% was achieved over CaO–NiO and CaO– Nd 2 O 3 catalysts.  The catalysts were used in several cycles without significant loss of activity. graphical abstract CaO-NiO CaO-Nd2O3 CaO-NiO CaO-Nd2O3 CaO 0 10 20 30 40 50 60 70 80 90 100 1 2 3 4 5 6 FAME yield (%) Run CaO article info Article history: Received 25 April 2014 Received in revised form 17 July 2014 Accepted 21 July 2014 Available online 31 July 2014 Keywords: Calcium-based mixed oxide High stability Jatropha curcas Solid base Transesterification abstract Calcium-based, CaO–NiO (calcium nickel) and CaO–Nd 2 O 3 (calcium neodymium) mixed oxides, were synthesized via co-precipitation process. Non-edible crude Jatropha curcus oil (JCO) was used as feed- stocks for fatty acid methyl esters (FAME) synthesis in the presence of CaO–NiO and CaO–Nd 2 O 3 mixed oxides. It was found that mixed solid bases oxides depicted high basicity and stability. Temperature pro- grammed desorption of CO 2 (CO 2 -TPD) confirmed that both strong and strongest basic sites existed on the surface of CaO–NiO and CaO–Nd 2 O 3 catalysts, respectively. Both mixed oxide catalysts also demon- strated high thermal stability, since X-ray diffraction (XRD) proved that the crystalline phases present in both mixed oxide catalysts preserved well as pure oxide even up to 900 °C. The FAME yield produced by CaO–NiO and CaO–Nd 2 O 3 catalysts were studied and compared with calcium oxide (CaO), nickel oxide (NiO), and neodymium oxide (Nd 2 O 3 ) catalysts. Both CaO–NiO and CaO–Nd 2 O 3 catalysts exhibited high activity as CaO and were easily separated from the product. CaO–NiO catalyst was found more active than CaO–Nd 2 O 3 during the transesterification reaction. The optimal reaction parameters for achieving the >80% of FAME yield were methanol/oil molar ratio 15:1, catalyst amount 5 wt.% and reaction temperature 65 °C. Reusability study suggests that catalysts could be recycled for six successive runs without signif- icant loss in activity. As a result, these new solid base mixed catalysts showed remarkable activity and durability in the synthesis of fatty acid methyl esters from crude JCO. Hence, the mixed oxides catalyst might be a valuable heterogeneous catalyst for FAME production. Ó 2014 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.fuel.2014.07.062 0016-2361/Ó 2014 Elsevier Ltd. All rights reserved. ⇑ Corresponding author at: Catalysis Science and Technology Research Centre, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia. Tel.: +603 89466809; fax: +603 89466758. E-mail address: taufiq@upm.edu.my (Y.H. Taufiq-Yap). Fuel 136 (2014) 244–252 Contents lists available at ScienceDirect Fuel journal homepage: www.elsevier.com/locate/fuel