Hydrocracking of waste chicken fat as a cost effective feedstock for renewable fuel production: A kinetic study

In this study, low cost waste chicken fat (WCF) feedstock was used for fuel-like hydrocarbon production. The effects of varying reaction parameters on the hydrocracking of waste chicken fat using NiW/SiO2-Al2O3 catalyst were investigated. The reactions were carried out in a fixed bed down flow reactor at reaction temperatures of 400-450 °C, liquid hourly space velocity (LHSV) of 1, 2, 4 h−1, H2/oil molar ratio of 450 v/v and hydrogen pressures of 6.0 MPa. The effects on hydrocracking conversion and distribution of products were investigated. The liquid product was analyzed using gas chromatography (GC) to quantify n-alkanes. Hydrocracking conversion and organic liquid products (OLPs) were evaluated by ASTM D-2887 distillation. The results showed that the catalytic hydrocracking of WCF generates fuels that have chemical and physical properties comparable to those specified for petroleum-based fuels. The amount of kerosene/diesel fractional product decreased with an increase in the temperature and a decrease in the LHSV; while gasoline like petroleum fuel increased. A considerable elimination of O2 from chicken waste fat molecules has been indicated by FTIR analysis. The oxygen removal pathway of WCF over NiW/SiO2-Al2O3 catalyst is primarily carried out by hydro-deoxygenation. The reaction was found to follow the second order mechanism, and the estimated activation energy Ea was 96 kJ mol−1. The exploited catalyst was employed in another run where the results showed the catalyst stability and can be used for several times.