Synthesis of biodiesel from Schizochytrium oil using renewable catalyst and study of its quaternary blend phase behaviour

Abstract

In this present work, waste animal bone is used for the first time to synthesis nano hydroxyapatite heterogeneous catalyst. The sodium nitrate salt was doped with synthesized nano hydroxyapatite to form sodium modified nano hydroxyapatite for transesterification of biodiesel from schizochytrium algae oil. Locally collected waste bone was washed, cleaned, dried, powdered and calcined at different temperature at 900 °C for 2 h to convert into tri-calcium phosphate and it is characterized. The synthesized heterogeneous catalyst was tested for biodiesel production. The maximum biodiesel yield of 96% was achieved at 9 wt.% catalyst concentration, 1:12 molar ratio and 2 h reaction time. The produced biodiesel was characterized to evaluate the quality for the application in diesel engines and the results exhibited that the properties are in ASTM standard limit. Blending of biodiesel, lower alcohol with diesel have been considered as the common fuel modification for reducing the pollution. In this study, the phase behaviour of the synthesized Schizochytrium biodiesel, diesel and higher alcohol (Octanol) was studied with water in oil emulsions (Quaternary blend). Octanol was used because of its high carbon number and better fuel property. The effects of different hydrophilic lipophilic balance were studied to find an optimum HLB number by varying the Span 80 and Tween 80 ratio (20 to 100%) in the quaternary blend. The optimum fuel blend was found at the HLB number of 12 (Span 20%: Tween 80%) and the quaternary blend at the HLB 12 showed no phase separation for two months.