Water-gas shift reaction at high temperature. Study of kinetics and catalyst deactivation on a Fe2O3-Cr2O3 catalyst.

The water-gas shift reaction on a commercial Fe2O3/Cr2O3 catalyst was studi ed in a packed bed reactor operated continuously under isothermal condition s. The experiments were conducted at a pressure of 1 MPa, at temperatures f rom 633 to 733 K and at feed composition (CO, CO2, H2O, and H-2 partial pre ssures) typical of H-2 production from reforming of natural gas. The tests for some catalyst samples, extended up to 250 h, showed that the catalyst u ndergoes an appreciable degree of deactivation during this period, which wa s enhanced by a high concentration of water. The reaction rate at a given l evel of activity showed an effective reaction order of about unity far CO a nd of about a half for water. The: reaction was significantly inhibited by CO2. The apparent activation energy, based on a power law expression, was f ound to be 72 kJ/mol.