Chemical looping reforming of waste cooking oil in packed bed reactor

Chemical looping steam reforming for hydrogen production from waste cooking oil was investigated using a packed bed reactor. The steam to carbon ratio of 4 and temperatures between 600 and 700 °C yielded the best results of the range of conditions tested. Six cycles at two weighted hourly space velocities (WHSV of 2.64 and 5.28 h−1) yielded high (>0.74) and low (<0.2) oil conversion fractions, respectively, representing low and high coking conditions. The WHSV of 2.64 h−1 yielded product concentrations closest to equilibrium values calculated assuming a fresh rapeseed oil composition. Repeated cycling revealed some output oscillations in reactant conversion and in the extent of Ni–NiO conversion, but did not exhibit deterioration by the 6th cycle. The selectivity of CO, CO2 and CH4 were remarkably constant over the performed cycles, resulting in a repeatable syngas composition with H2 selectivity very close to the optimum.