Catalytic co-pyrolysis of coffee-grounds and waste polystyrene foam by calcium oxide in bubbling fluidized bed reactor

Abstract

The high concentration of oxygenated components in biomass pyrolysis oil challenges the conversion of biomass to bio-fuels via fast pyrolysis. Herein, calcium oxide was prepared to convert the oxygenated compounds in the pyrolytic products of coffee-grounds to valuable hydrocarbons. Meanwhile, waste polystyrene foam was co-pyrolyzed with coffee-grounds to promote hydrogen transfer reactions, resulting from scission of the polystyrene radicals. The results show that calcium oxide could effectively reduce the concentration of undesired oxygenated compounds like phenols and fatty acids in pyrolytic products. The effects of calcium oxide and polystyrene were mainly reflected in the production of a deoxygenated organic fraction, rich in aromatics and with a considerable calorific value. An organic fraction with an oxygen content of 13.38 wt% was obtained at a catalyst-to-feedstock ratio of 1:8 and an amount of polystyrene foam of 20 wt%. This fraction, due to its properties and its compositions, is considered for use as potential feedstock in the energy market.▪.