Abstract:

To tackle high regeneration energy consumption and underused low-grade waste heat in natural gas desulfurization-regeneration units, this study introduces a mechanical vapor recompression (MVR) heat pump distillation retrofit. A closed-loop system is designed where regenerator overhead vapor, pressurized via MVR, directly heats the reboiler, enabling waste heat upgrading and thermal self-balance. Using sensitivity analysis, response surface methodology, and NSGA-Ⅱ, a multi-objective optimization framework targets energy conservation, efficiency, emissions, and costs. Thermodynamic analysis identifies 320.0 kPa compressor pressure as a critical efficiency inflection point where waste heat recovery outweighs compression energy costs. Optimization results show: H₂S flow fluctuations ≤0.13%, regeneration energy consumption reduced by 39.86%, and carbon emissions down 30.66%, achieve annual operating cost savings of 546000 CNY, with a static investment payback period of 3 a. This scheme provides an innovative path for the low-carbon transformation of natural gas purification, with both economic and environmental benefits.

Key words: absorption, optimization, steam recompression, response surface methodology, energy saving, genetic algorithm

摘要：

针对天然气净化厂脱硫再生工段现有工艺再生能耗高、塔顶余热利用率低问题，本研究提出了基于机械蒸汽再压缩（MVR）热泵蒸馏改造方案。通过构建吸收-再生模拟系统，创新设计塔顶蒸汽经MVR系统增压升温后供给再沸器热源的闭式循环架构，形成余热品位提升与热能自平衡的新型再生模式。基于能效分析与过程能耗评估，针对压缩机、换热器等建立操作参数优化模型，开发含敏感性分析、响应面法与非支配排序遗传算法（NSGA-Ⅱ）的协同优化框架，构建以节能增效、减排降本为核心的多目标体系，并采用三级递进策略提升能效。结果显示，改造后硫化氢流量波动≤0.13%，再生单元能耗降低39.86%，碳排放强度下降30.66%。该方案为天然气净化低碳改造提供了创新路径，兼具经济与环境效益。

关键词: 吸收, 优化, 蒸汽再压缩, 响应面法, 节能, 遗传算法