Design and utilization of a recyclable g-C3N4/Biochar@PEI-SO3H nanocatalyst for sustainable biodiesel production
Results in Engineering Vol. 32, 112430–112430
چکیده
Along with the search for renewable energy sources, many studies have been interested in biodiesel as a clean and biodegradable alternative to fossil fuels. However, separation, corrosion, and recycling problems limit traditional homogeneous catalysts practical application. In this work, a novel heterogeneous graphitic carbon nitride/Biochar@polyethyleneimine-sulfonic acid (g-C 3 N 4 /Biochar@PEI-SO 3 H) nanocatalyst was synthesized. The novelty of this work is the rational integration of the properties of graphitic carbon nitride, biochar, polyethyleneimine, and sulfonic acid into a heterogeneous nanocatalyst. This composite offers a Brønsted acid site density of 0.118 mmol/g in an accessible mesoporous structure (BET surface area: 13.62 m 2 /g) for efficient mass transfer and catalytic activity. The catalyst was prepared by a series of pyrolysis, polycondensation, functionalization and sulfonation processes. It was characterized by Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Diffraction (XRD), X-ray Fluorescence Sulfur Tester (XRF), Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray Spectroscopy (EDX), Thermogravimetric Analysis (TGA), and Brunauer–Emmett–Teller (BET) analysis. Then, applied for the esterification of oleic acid with methanol to produce biodiesel. Under the optimized reaction conditions (10 wt% catalyst, a 10:1 methanol-to-oleic acid molar ratio, and 65°C), the catalyst achieved a maximum biodiesel yield of 94% within 48 min. The produced biodiesel exhibited favorable fuel properties, including a flash point of 164°C, density of 0.870 g cm −3 (25°C), and a kinematic viscosity of 4.4 mm 2 s −1 (40°C), consistent with biodiesel fuel specifications. The catalyst exhibited high catalytic activity, good recyclability and offered a promising heterogeneous catalytic system for laboratory-scale biodiesel production.