Application of a Combined Catalyst and Sorbent for Steam Reforming of Methane

The performance of a combined catalyst and sorbent material designed for reforming hydrocarbons was evaluated by reacting methane with steam at different temperatures and pressures in a reactor packed with the material. The combined material was in the form of small spherical pellets comprised of a sorbent core of lime encased in a porous shell made largely of sintered alumina that supported a nickel catalyst. On the basis of previous research, two shell formulations were included in the study. One shell formulation contained a small quantity of CaO for strengthening of the shells, whereas the other contained a similar quantity of La2O3. Reaction testing of the combined catalyst and sorbent over a temperature range of 550-650 degrees C and a pressure range of 1.0-10.0 atm showed that pellets with either shell formulation were capable of producing H-2 at or near thermodynamic equilibrium levels during a period when CO2 was being rapidly absorbed by the core material. Limited lifecycle testing of the combined catalyst and sorbent was also conducted at 650 degrees C and 1.0 atm over 10 cycles of H-2 production and sorbent regeneration. A product stream with 98 mol % H-2 (dry basis) was produced during the rapid CO2 absorption period of each cycle. However, the length of this period declined with each cycle.