A device is disclosed for conducting an adsorption/desorption swing reaction. The desorption step of the reaction is conducted at least in part at a temperature below 100 C. Dry steam is used for purging the reactor and the adsorbent bed in the reactor. For this purpose the device has a water reservoir, and a vacuum source in fluid connection with the water reservoir and the reactor. During the desorption step the vacuum source causes water to evaporate, and the water vapor to flow through the reactor.

Systems and methods are provided for combined cycle power generation while reducing or mitigating emissions during power generation. Recycled exhaust gas from a power generation combustion reaction can be separated using a swing adsorption process so as to generate a high purity CO.sub.2 stream while reducing/minimizing the energy required for the separation and without having to reduce the temperature of the exhaust gas. This can allow for improved energy recovery while also generating high purity streams of carbon dioxide and nitrogen.