Title
Kinetics evaluation of non-isothermal microwave-assisted torrefaction of palm oil fibre: effect of microwave power level
Authors
INDAH HARTATI, NOVI CAROKO, NANANG MASRUCHIN, AGUNG NUGROHO and WILLIE CASTILLO BUCLATIN

Received October 16, 2025
Published Volume 60 Issue 5-6 May-June
Keywords kinetics, microwave, non-isothermal, oil palm fibre, torrefaction

Abstract
This study investigates the non-isothermal microwave-assisted torrefaction of oil palm fibre, focusing on the effect of microwave power levels on reaction kinetics and biochar yield. Microwave-assisted torrefaction (MAT) offers rapid volumetric heating and energy efficiency, making it a promising alternative to conventional thermal methods for biomass valorization. A modified kinetic model based on di Blasi and Lanzetta was applied to simulate the decomposition pathway, incorporating heating rate (β) and multi-step reactions involving biomass (A), intermediate product (B), final product (C), and volatile components (V1, V2). Experimental data revealed that increasing microwave power from 400 W to 800 W enhanced heating rates and volatile release, but reduced solid residue yield, indicating intensified thermal decomposition. The kinetic parameters and statistical validation (R², RMSE, SSE) confirmed the model’s robustness, particularly at 400 W. These findings demonstrate that MAT can be tuned to optimize biochar properties for multifunctional applications, such as carbon sequestration and thermal energy storage, contributing to climate mitigation and sustainable biomass utilization.