Optimization of Euphorbia rigida fast pyrolysis conditions by using response surface methodology

The objective of this study was to optimize the experimental conditions for obtaining the highest bio-oil yield from Euphorbia rigida (E. rigida) by fast pyrolysis using response surface methodology (RSM) based on central composite design (CCD). Experimental design was applied to optimize the reaction temperature, heating rate, and nitrogen gas flow rate which are the important parameters effecting the pyrolysis process. From the analysis of variance (ANOVA), the most influential factor of each experimental design response was identified and an empirical model in terms of factors was derived. The optimum conditions were found to be at reaction temperature of 600 °C, heating rate of 200 °C/min, and nitrogen flow rate of 100 mL/min. Maximum bio-oil yield was obtained as 35.3% under optimum conditions. Second-order polynomial equation for bio-oil yield was developed to correlate the parameters. A three-factorial design proved to be an effective model in studying the influence of the pyrolysis parameters.