Optimization of biodiesel production using magnesium pyrophosphate

Magnesium pyrophosphate catalysts synthesized via the thermal decomposition of dittmarite, struvite, and newberyite precursors were applied for biodiesel production by transesterification. Physicochemical properties of the catalysts and effects of operating transesterification conditions on the biodiesel yield were investigated. Analytical data revealed that the biodiesel yield decreases with increasing crystallite and particle sizes, but it increases with the basic site density and surface area of the catalyst. Further, the results indicate that struvite should be used as the precursor to synthesize the catalyst in order to realize the highest biodiesel yield. Using the struvite-derived catalyst under the optimized transesterification conditions, the highest biodiesel yield was obtained. The transesterification reaction showed pseudo-first-order kinetics. In addition, the activation energy, frequency factor, and rate constant were also determined. The purification step is not needed, resulting in lower biodiesel production cost. Therefore, this catalyst is applicable as a potential transesterification catalyst for industrial plants. (C) 2020 Elsevier Ltd. All rights reserved.