A process for producing a high temperature CO.sub.x-lean product gas from a high temperature CO.sub.x-containing feed gas, includes: providing a sorption enhanced reactor containing a first adsorbent, a shift catalyst and a second adsorbent; feeding into the reactor a feed gas containing H.sub.2, H.sub.2O, CO and CO.sub.2; contacting the feed gas with the first adsorbent to provide a CO.sub.2 depleted feed gas; contacting the CO.sub.2 depleted feed gas with the shift catalyst to form a product mixture comprising CO.sub.2 and H.sub.2; and contacting the product mixture with a mixture of second adsorbent and shift catalyst to produce the product gas, which contains at least 50 vol. % H.sub.2, and less than 5 combined vol. % of CO.sub.2 and CO. The adsorbent is a high temperature adsorbent for a Sorption Enhanced Reaction process, such as K.sub.2CO.sub.3 promoted hydrotalcites, modified double-layered hydroxides, spinels, modified spinels, and magnesium oxides.