PEER-REVIEWED ARTICLE bioresources.com Abd Hamid (2014). “Extraction of MCC from palm trunk,” BioResources 9(4), 7403-7426. 7403 Catalytic Extraction of Microcrystalline Cellulose (MCC) from Elaeis guineensis using Central Composite Design (CCD) Sharifah Bee Abd Hamid*, Zaira Zaman Chowdhury, and Md. Ziaul Karim Cellulosic fiber extracted from a non-woody, monocotyledonous species of palm tree trunk (PTT) was hydrolyzed with different concentrations of FeCl3 in the presence of hydrochloric acid. The dissolution properties of the amorphous region of palm tree cellulosic fiber (PTC) can be enhanced in the presence of Fe 3+ cations in acidic medium. The independent variables, including temperature (x1), time (x2), and concentration of metal chloride (FeCl 3) catalyst (x3), were optimized using central composite design (CCD). Responses were measured in terms of percentage crystallinity (y1) and yield (y2) of the prepared hydrocellulose. Analysis of variance (ANOVA) showed that temperature was the most influential factor for hydrolyzing the amorphous sections of cellulose. Under optimum conditions, the percentage crystallinity (y1) and yield (y2) were 68.66% and 83.98%, respectively. Scanning electron microscopy (SEM) analysis and X-ray diffraction techniques were used to obtain more information about the surface morphology and crystallinity of the prepared microcrystalline cellulose (MCC). Infrared spectroscopy and thermal analysis were performed to observe the effect of hydrolysis on the finished products. It was concluded that the addition of FeCl3 salt in acid hydrolyzing medium can substantially increase the crystallinity of palm tree trunk cellulose with significant morphological changes to yield microcrystalline cellulose (MCC). Keywords: Palm tree cellulose (PTC); Microcrystalline cellulose (MCC); Hydrocellulose; Central composite design (CCD); Percentage crystallinity; Amorphous sections Contact information: Nanotechnology and Catalysis Center (NANOCAT), University Malaya, Kuala Lumpur 50603, Malaysia; *Corresponding author: sharifahbee@um.edu.my INTRODUCTION Recently, research has focused on obtaining sustainable, green, and ecofriendly materials for versatile applications (Abdul Khalil et al. 2012; Khalil et al. 2013). Cellulose, the main component of all biomass, is the most abundant bio-macromolecule found in nature. It has been estimated that more than 7.5 × 10 10 tons of cellulose is produced annually (Habibi et al. 2010). Irrespective of biomass sources, the long-chain cellulose polymer consists of a linear homo-polysaccharide composed of d-glucopyranose units linked together by 1-4 linkages. The repeating unit of cellulose is the dimer of glucose, known as cellubiose (Moon et al. 2011; Chowdhury et al. 2014). In addition to biodegradability and renewability, the fabrication of cellulosic materials into micro as well as nano dimensions enhances favorable characteristics such as excellent mechanical properties, high crystallinity, and low molecular weight (de Mesquita et al. 2010). Preparation of microcrystalline cellulose (MCC) derived from renewable sources is presently a hot investigation area. Microcrystalline cellulose, a porous, non-fibrous, white, odorless, purified, crystalline powder, is perhaps the best filler-binder used currently for pharmaceutical products (Ejikeme 2008; Li et al. 2013). It has been extracted by partial