Optimization and characterization of bio-oil from fast pyrolysis of Pearl Millet and Sida cordifolia L. by using response surface methodology

Abstract

The objective of this study was to optimize experimental parameters to obtain the maximum bio-oil yield (BOY) from fast pyrolysis of Pearl Millet (PM) and Sida cordifolia L. (Sida) by using response surface methodology (RSM) based on the central composite design (CCD). Important fast pyrolysis process parameters such as particle size (PS), reaction temperature (T), and nitrogen gas flowrate (NGF) were optimized. The most influential factor of each experimental design response was identified and an empirical model was derived in terms of factors through ANOVA. The second-order polynomial equation for the BOY was developed to correlate the parameters. The cubic and quadratic models fit the data of PM and Sida the best, respectively. The maximum BOY of 48.27 and 48.00% for PM and Sida respectively were obtained at the optimum parameters of PS of 1.5 mm, T of 400 °C, and NGF of 200 mL min−1 for both biomasses. GC–MS analysis of the optimized bio-oil samples from PM and Sida indicated the presence of many important chemical compounds such as acids, alcohols, aldehydes, aromatics, ketones, phenols, and others. Therefore, PM and Sida can be used as feedstocks for fuels and chemicals production through fast pyrolysis.