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 Â°C and a pressure range of 1.0-10.0 atm showed that pellets with either shell formulation were capable of producing H2 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 Â°C and 1.0 atm over 10 cycles of H2 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.
Reprinted (adapted) with permission from Industrial and Engineering Chemistry Research 49 (2010): 4091, doi: 10.1021/ie901914c. Copyright 2010 American Chemical Society.