廢塑膠轉化產製高價值碳氫化合物之製程模擬與技術經濟分析

Abstract

本研究旨在建立一套系統性架構，針對廢棄塑膠裂解製程進行經濟與技術可行性評估，以克服複雜分離序列設計之挑戰並提升資源循環效率。在固定的製程設計基礎上，本研究採用程序模擬技術並結合自動化參數優化方法，透過動態調整各蒸餾塔之理論板數與進料位置，系統性地評估了六種操作策略及一組整合碳捕捉技術之製程效能。分析結果顯示，各條件間經濟指標的細微差異突顯了製程對原料組成與反應路徑之高度敏感性；其中，採用純 LDPE 進料之條件（Condition 1）在優化後展現強勁的經濟績效，達成 54.27 百萬美元之淨利與 0.188 之投資報酬率 (ROI)。此外，針對含 PET 之混合進料整合設計，儘管碳化反應使固體殘留率達 40.15% 且 ROI 調整為 0.169，該製程仍成功將設備購置成本 (Cp0) 穩健控制於 15.01 百萬美元，展現出良好的資本效率與工程韌性。本研究證實，即便在固定之流程架構下，透過精確的分離參數優化仍能顯著降低總產品成本 (TPC) 並平衡環境規範之需求，為廢棄塑膠裂解產業提供了一套實用的決策支援指標，有助於在獲利能力與永續發展之間識別出最具彈性的最佳操作路徑。

This study establishes a systematic framework for evaluating the economic performance of waste plastic pyrolysis processes, addressing the challenges of designing complex separation sequences to enhance resource recovery efficiency. Within a fixed process design architecture, this research employs process simulation and automated parameter optimization to systematically evaluate six distinct operating strategies and an integrated carbon capture case by dynamically adjusting theoretical stage counts and feed tray locations. Results indicate that the narrow margins between economic indicators across various conditions underscore the high sensitivity of process economics to feedstock composition and reaction pathways. Specifically, Condition 1 (pure LDPE feedstock) demonstrates robust economic performance, yielding a net profit of $54.27M and an ROI of 0.188 through optimized separation parameters. For PET-mixed feedstock, the integrated design maintains a competitive bare module cost (Cp0) of $15.01M, demonstrating acceptable economic performance despite trade-offs such as a 40.15% solid residue yield and an adjusted ROI of 0.169. This research confirms that, even within a fixed design basis, optimization of separation parameters is critical for minimizing total product cost (TPC) while balancing environmental compliance. Ultimately, this study provides a practical decision-support tool for industry stakeholders to navigate the trade-offs between profitability and environmental sustainability, identifying the economically favorable design among various alternatives.