The present work reports (a) new experimental data demonstrating the concept of sorption enhanced WGS reaction at different temperatures using a commercial WGS catalyst and Na2O promoted alumina as the CO2 chemisorbent, and (b) the effect of the sorption-reaction temperature on the TSSER process performance estimated by model simulation. Relatively slower kinetics of the sorption-enhanced WGS reaction imposes a lower bound (~ 200 C), while the thermal stability of the chemisorbent and the use of carbon steel sorber-reactors sets the upper bound (~ 550 C) of temperatures for practical operation of the TSSER process. Simulated process performances (sorption-reaction at 200 and 400 C, and regeneration at 550 C) show that the operation of the sorption-reaction step at 200 C increases the H2 and CO2 productivities of the process by, respectively, ~ 38% and 35 % without changing the (a) moles of H2 produced per mole of CO in the feed gas, and (b) net CO2 recovery as a compressed by-product gas. The total steam duty for the sorbent regeneration increases by ~ 14% for the lower sorption-reaction temperature operation. Another major benefit of the lower reaction temperature operation was a very large increase in the pressure of the CO2 by- product (e.g. 40 and 21 bars at, respectively, 200 and 400 C) when the reactor feed gas contained 20% CO + 80% H2O at a total pressure of 15 bar.