Membrane separators and reactors represent some of the most interesting options for process identification and modularization. In spite of intensive research and significant progress in material development and understanding of fundamentals of membrane properties and membrane processes, commercialization of inorganic membrane separation and reaction processes remains a big challenge. This paper summarizes important separation/permeation properties of several groups of inorganic membranes for molecular separation and discusses key hurdles in commercializing inorganic membrane separators and reactors for process intensification. Future research and development efforts should be focused on addressing these key hurdles including synthesis of membranes with higher permeance and stability, fabrication of low cost and high packing density membrane substrates, and development of cost-effective, scalable methods for synthesis of a membrane separation layer. Commercial applications of highly permeable water-selective zeolite membrane separation processes will be expanded to membrane reactors coupling reaction with the removal of water from the membrane reactor.