Biogas, a renewable energy source, is primarily composed of methane and carbon dioxide and other gaseous species. Biogas upgrading for removing CO₂ from raw biogas is a necessary step before the biogas to be used as vehicle fuel or injected into the natural gas grid. Therefore, the present work aimed to propose a low-temperature CO₂ removal process as an alternative to the conventional biogas upgrading technologies (water scrubbing, chemical and physical scrubbing, membranes and Pressure swing adsorption). A typical model biogas mixture of 60 mol.% CH₄ and 40 mol.% CO₂ is considered. The present process showed that a product purity of 94.5 mol.% CH₄ is obtained from compressed biogas by combining distillation, flash separation, auxiliary refrigeration and internal heat recovery with a potential specific energy consumption of 0.26 kW h/Nm³ raw biogas. The process has been simulated in Aspen HYSYS with avoiding the occurrence of CO₂ freeze-out. The process delivers the captured CO₂ in liquid form with a purity of 99.7 mol.% as a by-product for transport at 110 bar. It is concluded that the proposed upgrading process can serve as a new environmentally friendly approach to CO₂ removal with an interesting energy-efficient alternative to the conventional upgrading techniques.