Identification of Key Process Parameters on the Catalytic Fast Pyrolysis of Rio Red Grapefruit Waste to Value-Added Products

Abstract

Several process parameters, such as temperature, pressure, heating rate, contact mode, catalyst-to-biomass ratio, and reaction time, affect the catalyst performance and subsequent yield of products obtained via catalytic fast pyrolysis (CFP) of biomass feedstocks. The combined effect of these process parameters on the CFP of Rio Red grapefruit processing waste (GPW) has not been previously explored. In this work, the Plackett–Burman experimental design approach has been applied to the CFP of GPW to screen and identify the critical process parameters that affect the yield of aromatic, furanic, phenolic, and polycyclic aromatic hydrocarbon group of products over small, medium, and large-pore zeolites. The aromatic groups of compounds, namely, benzene, toluene, ethylbenzene, and various xylene isomers, were the predominant products for all catalysts that were investigated. Both temperature and reaction time were statistically significant for all the zeolites with maximum aromatic yields obtained at 900 °C and a reaction time of 10 s. An in situ mode of contact between the GPW, catalyst, and evolving vapors maximized the furanic yields. A heating rate of 0.1 °C/ms resulted in a maximum in the phenolic yields. Elevated pressures of 450 psi maximized the yield of aromatics over small-pore zeolites. The results provide the basic data needed to support development of an initial reactor design for the conversion of GPW to value-added products based on catalytic fast pyrolysis.