Malaysia is one of the largest producers of palm oil in the world, which inevitably would also result in huge production of oil palm biomass. Without proper management, this biomass could pose serious environmental problems. Oil palm mesocarp fiber (OPMF) is one type of oil palm biomass which can be processed further for useful application such as dye removal from water. In the present study, OPMF was thermally treated using microwave-assisted pyrolysis. The sample was characterized (proximate, ultimate, lignin content, BET, FTIR, and SEM) and investigated using thermogravimetric analyzer. The activation energy and pre-exponential factor achieved from the Kissinger, Kissinger-Akahira-Sunose (KAS) and Ozawa-Flynn-Wall (OFW) methods were 159.74, 161.90, 163.29 kJ mol−1, and 1.02 × 10−10, 1.90 × 10−13, 3.79 × 10−17 min−1, respectively. The dye removal performance was evaluated using methylene blue (MB) with parameters of initial concentration of MB, contact time, biochar dosage, temperature and pH. The kinetics of MB removal by OPMF was best described using the pseudo-second order kinetic model, followed by Elovich, pseudo-first order and Weber-Morris. As a conclusion, OPMF generated from oil palm processing has the potential to be used as alternative raw materials to produce biochar for dye removal application.Fil: Aziz, Muhammad Fakhrul Syukri Abd. School Of Chemical And Energy Engineering; MalasiaFil: Musa, Nur Fashya. Innovat. Centre In Agritech. For Advanced Bioprocessing; MalasiaFil: Sedran, Ulises Anselmo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Pujro Tarquino, Richard Alfonzo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Zakaria, Zainul Akmar. Universiti Teknologi Malaysia; Malasia