Optimizing the use of pyrolysis waste oil as a feedstock for the naphtha cracking process by hydrotreating and hydrocracking

In this study, a process using hydroprocessing technology was investigated to utilize waste plastic pyrolysis oil (WPPO) produced from a 10-ton/day commercial rotary kiln pyrolysis reactor as feedstock for the naphtha cracking center (NCC) process. Experiments were conducted using two continuous processes with different capacities to perform hydroprocessing and hydrocracking reactions. Reactivity according to feedstock processing, reaction stages, and process configuration, as well as the effects of process operating variables, were evaluated. Hydrocracking of the hydrotreated WPPO was found to result in particularly high performance compared to the single hydrocracking reaction alone. As the reaction severity increased, the yield and impurity reduction improved, finally achieving an impurity content close to commercial naphtha and a naphtha yield of approximately 93.3 wt.%. Additionally, hydrogen consumption was confirmed to be comparable to that in conventional oil refineries. This study confirmed that the operating conditions can be adjusted according to the desired yield and impurity content levels or the feed ratio to the NCC process, to select the appropriate operating conditions, and that commercial-level naphtha or naphtha suitable for the specifications of the NCC process can be produced from WPPO. • Offers insight into sustainable upgrading of plastic-derived pyrolysis oils • Demonstrates HDT-HCK as the optimal scheme validated through experimental study • Achieves near-commercial impurity levels with high naphtha yield (∼93 wt.%) • Enables flexible operation to meet NCC specs or optimize co-feed economics • Confirms feasibility of chemical recycling via NCC-compatible naphtha production