Abstract The aim of this work was to provide a complete exergy and energy analysis of three biogas upgrading technologies: amine scrubbing, water scrubbing and membrane separation processes. Biogas production and treatment represents a key-process for the application of Circular Economy principles, since allows to reuse/reconvert industrial by-products or agro-industrial waste in a product that can be used in different energy demanding sectors, after proper cleaning and upgrading processes. The three technologies here reported have been implemented in Aspen Plus flowsheets, and were used to upgrade a biogas to biomethane, meeting the UNIT/TS 11537:2019 standards for Biogas to be injected in the gas grid. Each units of all the simulated processes have been analysed calculating total exergy feed, total exergy produced and exergy loss, distinguishing that lost for irreversibility and as waste. Water scrubbing was characterized by the highest values of exergy efficiency (94.5%) and methane recovery (99%), whereas the lowest exergy efficiency belonged to membrane separation (90.8%) that returned also the largest specific energy consumption (0.94 kWh/m3 STP). Conversely, amine scrubbing was characterized by the lowest specific energy consumption value (0.204 kWh/m3 STP) but by an exergy efficiency of 91.1%.

中文翻译：

---

三种沼气提质工艺的火用及能量分析

摘要 这项工作的目的是提供三种沼气升级技术的完整火用和能量分析：胺洗涤、水洗涤和膜分离过程。沼气生产和处理是循环经济原则应用的关键过程，因为在适当的清洁和升级后，允许再利用/再转化工业副产品或农业工业废物，这些产品可用于不同的能源需求部门过程。此处报告的三项技术已在 Aspen Plus 流程中实施，并用于将沼气升级为生物甲烷，符合 UNIT/TS 11537:2019 将沼气注入气网的标准。对所有模拟过程的每个单元进行了分析，计算了总火用进给、产生的总火用和火用损失，区分因不可逆转而丢失的损失和浪费。水洗涤的特点是火用效率 (94.5%) 和甲烷回收率 (99%) 的最高值，而最低的火用效率属于膜分离 (90.8%)，它也返回了最大的比能耗 (0.94 kWh/m3 STP ）。相反，胺洗涤的特点是比能耗值最低 (0.204 kWh/m3 STP)，但火用效率为 91.1%。