Crude oil hierarchical catalytic cracking for maximizing chemicals production: Pilot-scale test, process optimization strategy, techno-economic-society-environment assessment

Crude oil direct catalytic cracking can effectively promote the production of chemicals. However, the heterogeneity of cracking depth of various distillates seriously restricts its industrialization. This study proposed a novel crude oil hierarchical catalytic cracking process for controlling the catalytic cracking depth. The key operating parameters were investigated and optimized using a multi-objective optimization strategy. A quantitative assessment for the life cycle techno-economic-society-environment of the novel processes was then conducted and compared with the conventional process. Results show that the optimized first and second flash unit temperatures are 187 °C and 251 °C. The optimized first and second riser outlet temperatures are 644 °C and 682 °C, respectively. The conversion rate and olefin yields of the novel process are increased by 1.47% and 1.46%. The hydrogen and carbon atoms efficiency in the novel process is 63.17% and 76.21%, which could raise 0.97% and 1.62% compared with the conventional process. Moreover, the novel process could increase 14.3% and 1.61%% in the net present value and internal rate of return. Meanwhile, it decreased by 2.1%, 8.2%, and 2.2% in greenhouse gas emissions, wastewater generation, and non-renewable energy consumption, compared with conventional crude oil-to-chemicals processes. These findings in this work could promote engineering application, process intensification, and key operating parameters optimization of crude oil direct catalytic cracking.