정유공정 전환유연성의 2단계 확률모형: 단조 이득과 조건부 가치 소멸의 구조적 분석

This study investigates the economic Value of Conversion (VoC) of heavy-to-light conversion units in petroleum refining processes under uncertain crude oil price environments by simplifying existing complex models into a two-stage stochastic programming model with a single-crude, dual-product structure. Since the conversion process embodies an option structure that includes "the right not to use," it never reduces expected profit; however, its economic value is determined by the tail distribution where the spread exceeds conversion costs and converges to zero under certain conditions. Mathematical analysis reveals that the economic value approaches nearly zero (VoC ≈ 0) when conversion costs are high, spread volatility is low, or the heavy oil fraction in crude is low. These findings are validated through numerical experiments reflecting 2020-2024 Korean refining market data and phase diagram analysis. By employing a minimal structural model, this study clarifies the dual characteristics of conversion flexibility-"monotonic benefit" and "conditional value erosion"-and derives critical curves in the parameter space of spread mean and volatility, conversion cost, and heavy oil fraction. The results provide quantitative guidelines directly applicable to refiners' investment decisions on conversion facilities and government prioritization of policy support.