TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Properties: The stream of gas and entrained particles has an axial velocity of 10-30 ft/second. The calcium oxide particles have a static-bed bulk density of 30 lbm/ft3.    TECHNOLOGY FOCUS - MECHANICAL ENGINEERING - Preferred Component: The reactor further comprises a bed of particles disposed in the fluidized-bed chamber above the plate. The impinging injector comprises the plate having a central orifice and a peripheral orifice. The central orifice extends perpendicularly through the plate. The peripheral orifice is disposed adjacent to the central orifice and extends through the plate at such an angle that a stream of reactants injected from the gas-manifold chamber into the fluidized-bed chamber through the peripheral orifice impinges on a stream of reactants injected into the fluidized-bed chamber through the central orifice. The reactor also comprises the plate having the peripheral orifices arranged in the plate such that the streams of reactants respectively injected through impinge on the stream of reactants injected through the central orifice at a common point and at a common acute angle; and an outlet end (212) of an outlet tube of the above dense-phase flow splitter coupled to the central orifice of the injector. The injector comprises four peripheral orifices. The ratio of the mass of the calcium oxide injected through the central orifice to the mass of the steam and methane mixture (35) injected through the peripheral orifices is 10-1. The steam and methane mixture is injected into the reactor bed through the peripheral orifices at a velocity of 650 ft/second. The percentage of the total flow of the steam and methane mixture injected into the reactor bed through the peripheral orifices is 10%. The percentage of the total flow of the steam and methane mixture injected into the reactor bed through the base-bleed orifices is 90%. The total differential pressure drop across the plate is 13 psi. The base-bleed orifices comprise a mixture of gases. Preferred Property: The pressure in the fluidized bed of the reactor is 7.8 atm, absolute.    TECHNOLOGY FOCUS - METALLURGY - Preferred Component: The particles comprise nickel-plated alumina particles (24).    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Properties: The stream of gas and entrained particles has an axial velocity of 10-30 ft/second. The calcium oxide particles have a static-bed bulk density of 30 lbm/ft3.