Enhancing light olefins and aromatics production from naphthenic-based vacuum gas oil: Process integration, techno-economic analysis and life cycle environmental assessment

Abstract

Global excess capacity of lubricating oil and high-value added utilization of naphthenic-based heavy oil concerns have attracted tremendous attention. Enhancing the highly efficient transformation for polycyclic aromatic hydrocarbons (PAHs) rich in naphthenic-based vacuum gas oil to light olefins and aromatics could be a promising solution through systematic process integration. Four naphthenic-based heavy oil processing schemes, hydrotreating, hydrocracking, hydro-upgrading and deep catalytic cracking, and a novel deep hydrogenation coupled with the two stage risers of maximizing propylene process (DHTMP), are brought up. The process simulation and models are established for the processing schemes to gain detailed mass balance and energy consumption results. The operating parameters are optimized for the purpose of maximizing light olefins and aromatics. The economic and life cycle environmental assessment are conducted to determine the superiority of DHTMP process over other schemes. The DHTMP process realized full recovery and utilization of low-value light cycle oil and efficient transformation of PAHs to light olefins and aromatics. Moreover, the DHTMP process shows great performance from the techno-economic and life cycle environment aspect. The results in this study have great guiding significance to the process intensification of PAHs in vacuum gas oil converting to light olefins and aromatics products efficiently.