Biodiesel Production from Black Soldier Fly (Hermetia illucens) Larvae via In-situ Interesterification Reaction with Biocatalyst from Rhizopus oryzae in Different Reactors ​

This study aimed to synthesize whole-cell biocatalysts from R. oryzae and apply them for in-situ interesterification of BSFL using methyl acetate and compare the yield and quality of biodiesel produced in stirred tank reactor (STR), continuous stirred tank reactor (CSTR), and continuous centrifugal contactor separator (CCCS). Whole-cell biocatalysts from R. oryzae were successfully synthesized with enzymatic activity of 4014.95 U/g and applied in an in-situ interesterification of BSFL lipid using methyl acetate to produce crude biodiesel. At a rotational speed of 180 rpm, the crude biodiesel yield illustrates similar profile for all reactors, with the highest yield after 20 h at 95.87 ± 1.88% (STR) and 94.19 ± 0.62% (CSTR), although no significant yield differences were observed after 16 h. The CCCS achieved the highest yield (94.49 ± 0.30%) at a higher rotational speed (2100 rpm). At steady-state, volumetric productivity ranged between 2.08–2.98 kg·m⁻³min⁻¹. Ester and triacetin contents of the biodiesel ranged from 75.46 to 75.67% and 18.80 to 18.92%. Physicochemical properties particularly density, water content, and kinematic viscosity met standard biodiesel specifications with no significant differences across reactors. The higher heating value ranged between 40.39–40.69 MJ/kg. These findings demonstrate BSFL’s considerable potential as an alternative feedstock for producing biodiesel.