Abstract:
This study presents the synthesis, characterization, and utilization of marine
macroalgae-derived biochar catalysts (BC and KOH-AC) for the production of
biodiesel from waste cooking oil (WCO). The biochar catalyst (BC) was produced via
slow pyrolysis of marine macroalgae biomass, which was subsequently activated with
potassium hydroxide (KOH) to produce a KOH-modified activated carbon catalyst
(KOH-AC). Advanced characterization techniques such as SEM, EDX, XRD, FTIR,
and TGA were used to examine the physicochemical and structural properties of the
synthesized catalysts. To evaluate the catalytic performance of marine macroalgaederived biochar catalysts, the impact of various transesterification variables such as
temperature, M/O ratio, time, and catalyst loading on the yield of biodiesel was
examined. It was found that the maximum biodiesel yields of 98.96% and 47.54%
were obtained using KOH-AC and BC, respectively, under optimal reaction conditions
of 65 °C of temperature, 12:1 of M/O molar ratio, 120 min of time, and 3 wt. % of
catalyst loading. The KOH-AC catalyst was recycled up to five times, with the fifth
cycle producing a significant biodiesel yield of 80.37%. Biodiesel characterization
using GC-MS confirmed the existence of 97.34% FAME compounds in the produced
biodiesel. The fuel characteristics of the produced biodiesel were analyzed, and the
results were compared to those of the ASTM Standard (D6751) and the EN Standard
(14214), which ensured that the produced biodiesel possesses excellent fuel properties
and can be used as a substitute for traditional fossil fuels.
