A method is disclosed for separating components of a gas. A feed gas stream is cooled in the first vessel. The feed gas stream comprises methane, carbon dioxide, and a secondary component. A first portion of the secondary component condenses, desublimates, or a combination thereof to form a primary stream, resulting in a first depleted gas stream. The first depleted gas stream is cooled in a condensing exchanger such that a first portion of the methane condenses as a first liquid methane stream, resulting in a second depleted gas stream. The second depleted gas stream is cooled in the second vessel such that a first portion of the carbon dioxide desublimates to form a solid product stream, resulting in a third depleted gas stream.