Abstract Liquefied natural gas (LNG) regasification process releases much cold energy, and LNG contains light hydrocarbon with high added value. The utilization of LNG cold energy and recovery of light hydrocarbon has been a research hotspot. In this paper, an energy integrated process of air separation and light hydrocarbon recovery driven by LNG cold energy is proposed. HYSYS is used to model and simulate the energy integrated process. For technical and economic analysis, cold energy utilization ratio (CUR), ethane recovery ratio (ERR) and partial annualized cost (PAC) are selected as the optimization objectives. Sensitivity analysis is conducted to investigate the influence trend of nine process parameters on optimization objectives. Next, a multi-objective model is introduced, and a genetic algorithm is used in multi-objective optimization. Finally, a compromised optimization scenario is determined based on three optimization objectives. The optimal key process conditions are determined: the temperature of stream L2 (outlet stream of air separation unit) is −129.6 °C, the temperature of stream L3 (outlet stream of demethanizer condenser) is −106.8 °C, and the vapor fraction of stream L4 (feed stream of demethanizer) is 0.6430. Results show that the CUR reaches 67.05%, ERR is 99.76%, and PAC is 3.144 × 107 USD/year.

中文翻译：

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LNG轻烃回收与空分能源整合：工艺设计与技术经济分析

摘要 液化天然气（LNG）再气化过程释放大量冷能，LNG含有高附加值的轻烃。LNG冷能的利用和轻烃的回收一直是研究热点。本文提出了一种以LNG冷能为驱动的空分与轻烃回收的能源集成工艺。HYSYS 用于对能量集成过程进行建模和模拟。在技​​术经济分析中，选择冷能利用率（CUR）、乙烷回收率（ERR）和部分年化成本（PAC）作为优化目标。通过敏感性分析研究了九个工艺参数对优化目标的影响趋势。接下来介绍多目标模型，并在多目标优化中使用遗传算法。最后，基于三个优化目标确定折衷优化方案。确定最佳关键工艺条件：流L2（空分装置出口流）温度为-129.6℃，流L3（脱甲烷冷凝器出口流）温度为-106.8℃，流 L4（脱甲烷塔的进料流）为 0.6430。结果表明，CUR 达到 67.05%，ERR 为 99.76%，PAC 为 3.144 × 107 美元/年。并且流L4(脱甲烷塔的进料流)的蒸气分数为0.6430。结果表明，CUR 达到 67.05%，ERR 为 99.76%，PAC 为 3.144 × 107 美元/年。并且流L4(脱甲烷塔的进料流)的蒸气分数为0.6430。结果表明，CUR 达到 67.05%，ERR 为 99.76%，PAC 为 3.144 × 107 美元/年。