Pyrolysis of Poultry Litter Fractions for Bio-Char and Bio-Oil Production

Abstract

Although production of activated carbon, catalytic gasification of poultry litter char, combustion, and physical treatment of poultry litter using screening have been thoroughly studied, yet eco-friendly and value added utilization of litter has not been adopted by the poultry industry. This paper examines whether or not screening and pyrolysis can be combined for value added utilization of poultry litter. Poultry litter was sampled from three commercial farms and each of the samples was divided into nine subsamples. These subsamples were randomly given nine treatments as follows: one control, screen #5 coarse fraction, screen #5 fine fraction, screen #10 coarse fraction, screen #10 fine fraction, screen #18 coarse fraction, screen #18 fine fraction, screen #20 coarse fraction, and screen #20 fine fraction. All coarse and fine fractions were pyrolyzed in a batch reactor at 500°C under a nitrogen flow rate of 2 lpm to produce char and condensate. The condensate was separated into three fractions based on density. Bomb calorimeter, proximate, and ultimate analysis were performed on un-pyrolyzed but screen- treated samples, char, and three phases of condensate. The results showed that the pyrolysis of the coarse fraction (screen#20) produced 44.5% char which retained 43.5% of total feedstock energy. Overall, the pyrolysis products captured 57.2% of total feedstock energy and 53.8% of total feedstock carbon. The light phase of the condensate (4.94% yields on dry biomass) had a calorific value of 34.83MJ/kg.