# A New Magnetically Separable BaFe2O4 Acid Catalyst for Sustainable Biodiesel Production: L9 Taguchi Optimization and Robust Recyclability

## TL;DR

This paper introduces a new magnetic catalyst for making biodiesel from waste cooking oil, which is efficient, reusable, and meets industry standards.

## Contribution

A novel magnetically separable BaFe2O4-based catalyst with high recyclability and performance for sustainable biodiesel production.

## Key findings

- The catalyst achieved 96.4% conversion of waste cooking oil into methyl esters under optimized conditions.
- The catalyst retained over 90% efficiency after seven cycles, showing excellent recyclability.
- Produced biodiesel met ASTM D6751 and EN 14214 standards, indicating industrial viability.

## Abstract

The MoO3/BaFe2O4 catalyst
was
synthesized via a combined coprecipitation and wet impregnation approach
and subsequently applied in the methyl biodiesel production from waste
cooking oil (WCO). The material was characterized using surface acidity
measurements, XRD, FTIR, SEM, EDS, and VSM techniques. The results
confirmed: (i) the successful synthesis of barium ferrite (BaFe2O4), and (ii) the effective impregnation of MoO3 onto the ferrite matrix. Process optimization was conducted
using the Taguchi L9 methodology, evaluating four operational
parameters: temperature (120–180 °C), methanol:WCO molar
ratio (20:1–40:1), catalyst concentration (2–10 wt %),
and reaction time (1–5 h). The high coefficient of determination
(R
2 = 0.9410) confirmed the model’s
robustness and predictive capability for ester content. The optimal
conditions (temperature = 172 °C, methanol:WCO molar ratio =
28:1, catalyst concentration = 7.5 wt %, time = 4 h) yielded a maximum
conversion of 96.4% into methyl esters. Notably, the catalyst exhibited:
(i) exceptional recyclability, maintaining efficiency above 90% after
seven consecutive cycles, and (ii) facile magnetic separation under
an external magnetic field. Furthermore, the physicochemical properties
of the produced biodiesel fully complied with ASTM D6751 and EN 14214
standards, underscoring the catalyst’s potential for industrial-scale
transesterification processes.