Diversification of resources is a key of sustainable production. In C1 chemistry, an efficient route of utilizing natural gas as chemical source, natural gas is reacted with air (oxygen) and/or steam to produce synthesis gas. Hydrocarbon mixtures and a wide variety of oxygenates can be produced at 150°-300°C. Since product yield is thermodynamically limited in a large number of reactions in C1 chemistry, it would be noteworthy to consider development of membrane reactor for improving process efficacy. ZSM-5 type and mordenite-type zeolite membranes for high temperature water separation from synthesis gas were developed. Perspectives of these hydrophilic zeolite membranes for removing water from such reaction systems were presented. This is an abstract of a paper presented at the AIChE Annual Meeting (San Francisco, CA 11/12-17/2008).