Biogas has been considered as an alternative renewable energy, and raw biogas needs to be upgraded in order to be used as vehicle fuels or injected into the natural gas grid. In this work, the conceptual process for biogas upgrading using aqueous choline chloride (ChCl)/urea (1:2 on a molar basis) was developed, simulated and evaluated based on the commercialized software Aspen Plus. Reliable thermophysical properties and phase equilibria are prerequisite for carrying out process simulation. In order to carry out the process simulation, the thermophysical properties of ChCl/Urea (1:2) and its aqueous solutions as well as the phase equilibria of gas-ChCl/Urea (1:2), ChCl/Urea (1:2)-H₂O and gas-ChCl/Urea (1:2)-H₂O were surveyed and evaluated. After evaluation, the consistent experimental data of these thermophysical properties were fitted to the models embedded in Aspen Plus. The properties needed but without available experimental results were predicted theoretically. The Non-Random Two-Liquid model and the Redlich-Kwong equation (NRTL-RK) model were used to describe the phase equilibria. The equilibrium approach was used for process simulation. Sensitivity analysis was conducted to determine the reasonable operating parameters. With a set of reasonable operating conditions, the effects of ChCl/Urea (1:2) content on the total energy utilization, the diameters and pressure drops of absorber and desorber as well as the environmental assessment of the process were studied. The simulation results showed that, with the addition of ChCl/Urea (1:2), the total energy utilization decreased by 16% compared to the process with pure water, and the diameters of both absorber and desorber decreased with increasing content of ChCl/Urea (1:2). The process using aqueous ChCl/Urea (1:2) was more environmentally benign than that with pure water. Therefore, aqueous ChCl/Urea (1:2) is a promising solvent for biogas upgrading.

沼气被认为是可替代的可再生能源，原始沼气需要进行升级以用作车辆燃料或注入天然气网格。在这项工作中，基于商业化的软件Aspen Plus开发，模拟和评估了使用氯化胆碱水溶液（ChCl）/尿素（摩尔比为1：2）进行沼气提质的概念过程。可靠的热物理性质和相平衡是进行过程模拟的前提。为了进行过程模拟，需要考虑ChCl / Urea（1：2）及其水溶液的热物理性质，以及气-ChCl / Urea（1：2），ChCl / Urea（1：2）的相平衡。 ）-H ₂ O和气体-ChCl /尿素（1：2）-H ₂对O进行了调查和评估。评估后，将这些热物理性质的一致实验数据拟合到Aspen Plus中嵌入的模型中。理论上需要预测所需的特性，但没有可用的实验结果。使用非随机两液模型和Redlich-Kwong方程（NRTL-RK）模型来描述相平衡。平衡方法用于过程仿真。进行灵敏度分析以确定合理的操作参数。在一组合理的操作条件下，研究了氯甲烷/尿素（1：2）含量对总能量利用，吸收器和解吸器的直径和压降以及该过程的环境评估的影响。模拟结果表明，添加ChCl /尿素（1：2）后，与纯水工艺相比，总能量利用率降低了16％，吸收剂和解吸剂的直径均随ChCl /尿素（1：2）含量的增加而减小。与纯水相比，使用氯化氢/尿素水溶液（1：2）进行的过程对环境无害。因此，含水的ChCl /尿素（1：2）是沼气提纯的有前途的溶剂。