Fuel, cilt.397, 2025 (SCI-Expanded)
In this study, fast pyrolysis parameters such as biomass particle size (PS), temperature (T), and carrier gas flow rate (CGF) were optimized by using the Response Surface Methodology (RSM) with a Central Composite Design (CCD) to maximize bio-oil yield (BOY) from olive pomace (OP). In addition, the effects of catalysts (Al2O3, Na2CO3, K2CO3, and ZSM-5) on the quality of bio-oil from fast pyrolysis of OP were investigated under the pre-optimized conditions (at 1.5 mm PS, 200 mL min−1 CGF), and reaction T of 425, 500, 575, 650, and 725 °C. The maximum BOY of 58.13 % was obtained at 1.5 mm PS, 490 °C T, and 200 mL min−1 CGF. The optimum reaction T for all four catalysts was 500 °C and the highest BOY was 50.73 % using Al2O3 as a catalyst. The Al2O3 and ZSM-5 had the lowest and highest bio-oil oxygen content ranging between 12.53 and 5.73 % and 15.06 and 12.55 %, respectively. The GC–MS analysis revealed that without a catalyst, bio-oil from OP contains mostly acids and small amounts of alcohol, aromatics, and ketones. The use of all four catalysts had major effects on bio-oil chemical compounds and distribution. Carboxylic acid contents of bio-oil samples from catalytic fast pyrolysis (CFP) of OP decreased significantly but aromatic content increased considerably and reached its highest (56.13 %) for Al2O3. Low aromatic content was observed when using Na2CO3 as a catalyst. Ketone and alcohol contents in bio-oil increased when using K2CO3, Na2CO3, and ZSM-5 as catalysts.