Algal biodiesel production with engineered biochar as a heterogeneous solid acid catalyst.

•Efficiency of acidified biochar catalyst for transesterification was evaluated.•Peanut shell biochar pyrolyzed at 400 °C showed best catalytic efficiency.•Yield of biodiesel was influenced by the operational parameters.•Maximal biodiesel yield of 94.91% was obtained with significant FAMEs.•16.83% of oleic acid and 12.15% palmitic acid was present in algal biodiesel.