The energy efficiency and the environmental consequences of typical coal upgrading processes, such as combustion, depend to a large extent on the degree of gas separation, recovery, and recycle. Among the available methods used in chemical industry for a variety of gas separation tasks, the technology of polymer membranes offers several advantages such as low size, simplicity of operation and maintenance, compatibility, and use with a diversity of fuel sources. To examine the impact of membrane separation on coal upgrading processes, the Aspen Plus simulation software was used, in combination with developed membrane mathematical models. Energy analysis in coal combustion processes, where the main scope is CO2 removal, showed that very promising results can be attained. It is estimated that 95% of the emitted CO2 can be captured with a moderately low energy penalty (10%). This penalty can be further decreased if higher selectivity and/or permeability polymers can be developed.