CO2 emissions are the main cause of global warming. To reduce the greenhouse effect, it must be separated from other emission sources such as chemical plants and power plants. Conventional processes such as absorption, cryogenic distillation, and adsorption are used for this purpose, but drawbacks such as high energy consumption, process complexity, and capital cost must be addressed. Membrane separation is a new technology that is compact, energy efficient, environmentally friendly, scalable, and possibly more economical than existing technologies.