Pyrolysis treatment of poultry processing industry waste for energy potential recovery as quality derived fuels

Abstract

The paper presents the thermal–chemical treatment of residues from poultry slaughterhouses using the pyrolysis process for derived fuel production with high energy density properties, as alternative solution for waste to energy conversion. The residue consists of chicken feathers with traces of blood and offal, sampled directly from the industrial processing line. A specially designed tubular batch reactor was used for the externally heated atmospheric pressure pyrolysis. Experimental campaign reliability was ensured by using raw waste products and industrial operating parameters with temperatures in the range of 350–800°C.The experiments were developed with respect to sample mass reduction rate, thermal degradation process kinetics, reaction products distribution, physical–chemical properties and specific energy content. The influence of process parameters on char, tar and gas formation was quantified along with the mechanisms involved. The experiments revealed that minimum treatment periods for complete volatile fraction release vary between 35min and 3min depending on process temperature. The char mass fraction represents 40% to 10% of the pyrolysis products. The minimum tar fraction is generated at 350°C and increases continuously to the maximum reached at 600°C. The pyrolysis gas yield is quasi-constant between 350°C and 450°C and decreases with temperature rising. The energy content of pyrolysis products was determined based on their low heating value and mass fractions. The study aimed at minimum energy consumption and quality derived fuels production using the pyrolysis process as pretreatment stage applied to a potential renewable fuel with high specific energy density (HHV-26MJ/kg) but low combustible properties due to high water content (up to 70%).