Adsorption processes with activated carbons can be used to remove heavy hydrocarbons from a natural gas flow. Using the Pressure Swing Adsorption (PSA) technology, one can introduce a flexible solution in pre-existing gas-processing units to deal with new marked demands, as for example a C₃₊ free gas composition to be used as adsorbed natural gas to vehicles fuel tanks. However, designing a PSA process is a laborious task because several cycle configurations and materials are available to perform the separation. To fulfill such task, a multiscale procedure is proposed. Molecular simulation, through Grand Canonical Monte Carlo (GCMC) method, was used to obtain adsorption isotherms for natural gas components in three different carbons: WV-1050, NORIT R1 and MAXSORB. Bed geometry was set based on the minimum fluidization velocity and on the working capacity of the adsorbents. Working capacities were calculated using Langmuir Isotherm applied to Ideal Adsorbed Solution Theory (IAST) to represent the mixture. Each PSA column was simulated in Aspen Adsorption® and operates according to a four steps cycle (Skarstrom cycle): pressurization, adsorption at 40 bar, blowdown, and purge at 1 bar. The operating conditions of the process (such as flowrates, bed geometry and step times) were optimized, seeking the maximization of the process performance parameters: purity, recovery and productivity. A preliminary design of the PSA unit indicates the carbon WV1050 as the best adsorbent to produce C₃₊ free gas fuel, ideal for storage by adsorption.

使用活性炭的吸附过程可用于从天然气流中去除重质烃。使用变压吸附 (PSA) 技术，可以在现有的气体处理装置中引入一种灵活的解决方案，以满足新的显着需求，例如 C ₃₊游离气体组合物用作吸附天然气到车辆燃料箱。然而，设计 PSA 工艺是一项艰巨的任务，因为有多种循环配置和材料可用于执行分离。为了完成这样的任务，提出了一种多尺度程序。分子模拟，通过 Grand Canonical Monte Carlo (GCMC) 方法，用于获得三种不同碳中天然气组分的吸附等温线：WV-1050、NORIT R1 和 MAXSORB。基于最小流化速度和吸附剂的工作能力设置床几何形状。使用适用于理想吸附溶液理论 (IAST) 的朗缪尔等温线来计算工作容量，以表示混合物。每个 PSA 柱都在 Aspen Adsorption® 中模拟，并根据四步循环（Skarstrom 循环）运行：加压、吸附压力为 40 巴，排污和吹扫压力为 1 巴。优化了工艺的操作条件（例如流速、床层几何形状和步骤时间），以寻求工艺性能参数（纯度、回收率和生产率）的最大化。PSA 装置的初步设计表明，碳 WV1050 是生产 C 的最佳吸附剂₃₊游离气体燃料，是吸附储存的理想选择。