Bio-Oil Production from Date Palm Surface Fibers: Thermo-Kinetic and Pyrolysis GC/MS Analysis

Date palm surface fibers (DPSFs) are abundantly available as municipal and agricultural biomass wastes from date palm trees, especially in the Middle Eastern and North African countries, especially United Arab Emirates. DPSFs are lignocellulosic in nature and therefore have immense potential to be used for bioenergy purposes. This study presents the conversion-dependent pyrolysis behavior, kinetic analysis, and bio-oil qualitative investigation. DPSFs were analyzed using thermogravimetric analysis at nonisothermal heating rates of 10-40 °C/min at a temperature range of 20-750 °C. Activation energy (<i>E</i> _a) was calculated using model-free kinetics approach using Ozawa-Flynn-Wall (OFW), Kissinger-Akahira-Sunose (KAS), and Starink (STK) methods. <i>E</i> _a analysis helps understand the link up of degradation behavior as a function of the conversion and fragmentation of cellulose, hemicellulose, and lignin. The pyrolysis of DPSFs was performed in a horizontal quartz tube flow reactor at a heating rate of 40 °C/min and within a temperature range of 20-400 °C. The condensed bio-oil was tested for qualitative analysis using a gas chromatography and mass spectroscopy (GC/MS) technique. <i>E</i> _a values for the active pyrolysis region within a conversion range of 0.2-0.8 were 154.52, 152.40, and 152.37 kJ/mol for the OFW, KAS, and STK models, respectively. Using GC/MS, the qualitative assessment of bio-oil, based on normalized peak area percentages, showed that it consisted mainly of aliphatics (42.28%), aromatics (38.68%), and furans/other oxygenates (13.47%). 10.54% benzene and 10.94% toluene were the main contributors of aromatics, and 6.735 furfural was a dominant furanic compound. The result of this study provides an information on the composition of DPSF pyrolyzed bio-oil and suggests that the aromatic rich nature will lead to targeted recovery of BTX/phenolics compounds as well as for bioenergy applications.