The effect of demineralization and torrefaction consequential pre-treatment on energy characteristic of palm empty fruit bunches N. N. Kasim 1,2 • A. R. Mohamed 3 • M. A. M. Ishak 1 • R. Ahmad 2,4 • W. I. Nawawi 1,5 • S. N. Ali 1,2 • K. Ismail 1,2 Received: 30 January 2018 / Accepted: 22 March 2019 Ó Akade ´miai Kiado ´, Budapest, Hungary 2019 Abstract In this study, the effect of chemical and thermal pre-treatments on the chemical properties of palm empty fruit bunches (EFB) was investigated via a consecutive pre-treatment of demineralization and torrefaction. The pre-treatment was carried out on untreated EFB using acid leaching followed by heating the demineralized EFB (DEFB) at temperature of 200–280 °C in a 40 cm 3 of vertical tubular reactor with nitrogen flow rate of 100 mL min -1 . The untreated EFB and pre- treated EFB namely DEFB, torrefied EFB and torrefied demineralized EFB (TDEFB) were characterized using proximate and ultimate analyses, fuel properties, i.e. mass yield, energy yield and energy density, and Fourier transform infrared spectroscopy. Thermogravimetric analysis was used to study the thermal behaviour of the pre-treated EFB with untreated EFB as a comparison. The results revealed that this consecutive pre-treatment improved the properties of a solid fuel with high carbon content and lower in ash content have been observed in TDEFB. The higher temperature of torrefaction gives the lower the mass and energy yield but higher in the energy density. Furthermore, decomposition of hemicellulose increased as the torrefaction temperature increased due to the removal of carbonyl and hydroxyl group during the process. The relevance of this pre-treatment revealed that TDEFB has high potential as solid biofuel feedstock for further thermal conversion such as pyrolysis. Keywords Demineralization Á Torrefaction Á Empty fruit bunch (EFB) Á Energy characteristic Á Thermal behaviour Introduction Lignocellulosic is the main component in plant that con- sists of hemicellulose, cellulose and lignin. It has an abundance of organic component such as carbohydrate source that gives significant potential to be an alternative to non-renewable energy fossil fuel [1]. Due to high demand for the energy consumption around the world, lignocellu- lose biomass is forecasted to fulfil the role as renewable energy resources for producing future fuel energy used in the transportation sector. One of the famous biomasses in Malaysia is oil palm (Elaeis guineensis) which has become the world’s largest exporter of palm oil, overtaking Indonesia, Nigeria and Belgian Congo [2]. In addition, abundant oil palm waste has been produced during the refined, bleached and deodorized (RBD) palm oil pro- cessing [3]. The shortage of energy resources especially for those countries that consume more energy need to be uti- lized their own natural resources like rice husk and Mis- canthus from agricultural wastes and energy crops, respectively in Turkey [4]. Fortunately, Malaysia is rich in natural renewable resources which have significant poten- tial biomass in order to fulfil the nation’s energy demand. & N. N. Kasim nurnasulhah@uitm.edu.my 1 Coal and Biomass Energy Research Group, Universiti Teknologi MARA (UiTM), 40450 Shah Alam, Selangor, Malaysia 2 Faculty of Applied Sciences, Universiti Teknologi MARA Malaysia, 40450 Shah Alam, Selangor, Malaysia 3 Faculty of Engineering Technology, Unicity Alam, UniMAP, 02400 Padang Besar, Perlis, Malaysia 4 School of Environmental Engineering, Universiti Malaysia Perlis, 02600 Arau, Perlis, Malaysia 5 Department of Chemistry, University of York, Heslington, York YO10 5DD, UK 123 Journal of Thermal Analysis and Calorimetry https://doi.org/10.1007/s10973-019-08206-8