This study was undertaken for the development of a novel Electrochemical Hydrogen Separator (EHS) technology for low-cost hydrogen separation from coal derived gases. Design and operating parameter testing was performed using subscale cells (25 cm{sup 2}). High H{sub 2} purity, >99% is one of the main features of the EHS. It was found that N{sub 2}, CO{sub 2} and CH{sub 4} behave as equivalent inerts; EHS performance is not affected by the balance of feed gas containing these components. This product purity level is not sacrificed by increased H{sub 2} recovery. CO, however, does adversely affect EHS performance and therefore feed stream pretreatment is recommended. Low levels of H{sub 2}S and NH{sub 3} were added to the feed gas stream and it was verified that these impurities did not affect EHS performance. Task 2 demonstrated the scale-up to full size multi-cell module operation while maintaining a stable energy requirement. A 10-cell full-size module (1050 cm{sup 2} cell active area) was operated for over 3,800 hours and gave a stable baseline performance. Several applications for the EHS were investigated. The most economically attractive systems incorporating an EHS contain low pressure, dilute hydrogen streams, such as coal gasification carbonate fuel cell systems, hydrogen plant purification and fluid catalytic cracker units. In addition, secondary hydrogen recovery from PSA or membrane tailstreams using an EHS may increase overall system efficiency.