Sustainability assessment of electrified naphtha cracking pathways for carbon-neutral ethylene production

초록

Ethylene production via naphtha steam cracking is one of the most energy- and carbon-intensive processes in the petrochemical industry. As global efforts toward carbon neutrality accelerate, electrification has emerged as a promising pathway for reducing reliance on fossil fuel combustion. This study evaluates the sustainability of electrified naphtha cracking, considering both electrified steam cracking and plasma arc cracking, using six electricity sources and multiple methane utilization pathways. Industrial-scale process models, supported by pilot-scale data for plasma cracking, were developed to obtain detailed material and energy balances. Comprehensive techno-economic analysis (TEA), life cycle assessment (LCA), and carbon avoidance cost (CAC) evaluation were performed. The results show that plasma cracking achieves higher ethylene selectivity but requires a substantially higher energy input than electrified steam cracking. Economically, electrified steam cracking with methane-to-blue-hydrogen conversion powered by wind achieved the lowest levelized cost of ethylene (LCOE) ($1.66/kgethylene)andanegativeCAC(–$89.30/tonne CO2-eq), indicating simultaneous cost savings and emission reduction. Environmentally, the lowest emissions occurred in a case study with plasma cracking with methane-to-blue-hydrogen conversion powered by hydropower, achieving an 80.32% reduction relative to that of conventional naphtha steam cracking. Monte Carlo simulation confirmed the robustness of this finding, with the most cost-effective configuration showing an 86.5% probability of CAC below the current carbon price. Overall, this study identified renewable-powered electrified steam cracking combined with carbon-capture-enabled methane utilization as the most cost-effective near-term pathway for carbon-neutral ethylene production, while highlighting the efficiency improvements needed for future plasma cracking technologies.

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