Gas separation by adsorption processes such as pressure swing adsorption (PSA) presents an attractive alternative for upgrading biogas to biomethane. A new vacuum pressure swing adsorption (VPSA) cycle is proposed for a unit designed to purify pre-cleaned biogas (40% CO₂ and 60% CH₄) in industrial conditions (feed flow rate more than 500 Nm³/h and large-volume equipment). The process simulations performed to optimize the VPSA unit consider the kinetic separation of the feed components by using an appropriate carbon molecular sieve (CMS) adsorbent having a high kinetic separation selectivity for CO₂ with respect to CH₄. The designed VPSA unit is composed of five columns that perform three equalization steps. Minimizing methane losses during the regeneration steps necessitates injecting part of the off-gas rich in CO₂ at the bottom of the column during the production step to push the CH₄ forward. The produced biomethane meets the specification (97% CH₄) of grid injection purity. The developed cycle allows a CH₄ recovery of 92% to be obtained with a specific energy consumption of 0.35 kWh/Nm³, thus meeting the initial requirements for industrial exploitation of VPSA technology for biomethane purification from biogas sources.

通过变压吸附（PSA）等吸附过程进行气体分离是将沼气升级为沼气的一种有吸引力的替代方法。提出了一种新的真空变压吸附（VPSA）循环，用于设计用于在工业条件（进料流量大于500 Nm ³ / h和大流量）下净化预净化沼气（40％CO ₂和60％CH ₄）的装置。音量设备）。为优化VPSA单元而进行的过程模拟考虑了进料组分的动力学分离，方法是使用适当的碳分子筛（CMS）吸附剂，该吸附剂对CH ₄具有对CO ₂的高动力学分离选择性。设计的VPSA单元由执行三个均衡步骤的五列组成。在再生步骤中将甲烷损失降至最低需要在生产步骤中将部分富含CO ₂的尾气注入塔底以推动CH ₄前进。产生的生物甲烷符合格栅注入纯度的规格（97％CH ₄）。所开发的循环允许以0.35 kWh / Nm ^3的单位能耗获得92％的CH ₄回收率，从而满足VPSA技术用于从沼气中纯化沼气的工业开发的初始要求。