Production of fuel from the catalytic cracking of pyrolyzed poultry DAF skimmings

A two-step thermochemical process, pyrolysis followed by catalytic cracking, was used to produce liquid fuels from poultry dissolved air flotation (DAF) skimmings, a waste material generated during poultry processing. Raw DAF-derived solids were dried and subjected to pyrolysis at 400, 500, 600 or 700 °C to thermally crack the material into three physical phases; a gas, solid, and liquid. The liquid phase, DAF bio-oil, was further processed in an attempt to produce a liquid fuel capable of powering a diesel engine. After catalytic processing and collection, the DAF bio-oil exhibited a higher heating value (HHV) of 36 MJ kg−1, which is less than the reported HHV of diesel (45.7 MJ kg−1), similar to biodiesel (36-40 MJ kg−1), but much higher than the HHV of bio-oil produced from the bioconversion of woody biomass (20 MJ kg−1). DAF bio-oil analysis generated measurements of HHV (MJ kg−1), cloud point (°C), viscosity (mm2 s−1 at 40 °C), and water content (%) revealed values of 36, 61.7, 37.8, and 4.72, respectively. After catalytic cracking, HHV increased to 40.2 MJ kg−1, cloud point decreased to −2.7 °C, viscosity decreased to 1.6 mm2 s−1, and water content decreased to 1.9% making it comparable to conventional fuels. The upgraded DAF bio-oil could be utilized as a fuel for direct combustion in industrial boilers for steam generating, blended with petroleum fuels as an additive, or used directly as diesel transportation fuel.