While membrane technology is still young and has great potential for furthe
r improvements, it has been proven economical and technically efficient in
many applications such as treatment of natural gas. In this paper a brief h
istory of membrane gas separation technology is presented, and the theoreti
cal aspects of the process are discussed. The article also introduces appli
cations of membranes in the natural gas industry, discusses different syste
m designs and the effects of operating parameters on the performance of mem
brane systems, and compares the technical and economical aspects of membran
e processes with conventional technologies.