摘要
The operation types and operation window for high-purity H 2 production for the sorption enhanced steam methane reforming (SE-SMR) with Ni/Al 2 O 3 catalyst and CaO sorbent in a fixed-bed reactor are investigated by an experimentally verified 2D numerical method. Four chemical reactions including steam reforming, water gas shift, global steam reforming, and CO 2 sorption are considered. The operation window is defined as the H 2 and CO molar fractions at outlet satisfying both y H2,out ≥ 90% and y CO,out ≤ y CO,allow (= 1%, 2% or 3%) in dry base. Under the conditions of y H2,out and y CO,allow , there are six operation types, of which 2 types are within the operation window and 4 types are not within the operation window as the temperature, weight hourly space velocity (WHSV) and steam to methane (S/C) molar ratio vary. For a common case of S/C = 3, the operation windows for y CO,allow = 3% at WHSV = 8.5 h −1 and 42.5 h −1 are located at 570–670 °C and 640–690 °C respectively, based on the parameters in this work. The operation window of temperature is wider with decreasing WHSV, and it becomes wider remarkably as the S/C ratio increases. The lowest temperature inside the operation window is 550 °C. The effects of the temperature, WHSV and S/C ratio on the operating types, y H2,out and y CO,out are also presented and discussed in details.