In a previous work, the pyrolytic gasification of biomass (wood) using a stoichiometric nickel aluminate catalyst in a fluidized-bed reactor gave near-equilibrium yields of products above 650 degrees C, with 85-90% gas yields and no detectable tar production Additional tests are reported for a modified nickel-magnesium aluminate stoichiometric catalyst, to give greater physical strength, and for the addition of potassium, as a promoter. The addition of Mg in the catalyst crystal lattice did improve resistance to attrition but resulted in a minor loss in gasification activity and increased coke production. Addition of potassium had little effect. Catalyst deactivation by secondary carbon deposits was demonstrated, and regeneration of the Mg-containing catalysts by burn-off appears to be feasible. The deactivation process was experimentally simulated. A conceptual process for catalytic pyrogasification of biomass was modeled.