Sodium carbonate and carbonate minerals have been used in situ to neutralize the HCl generated during oxidation of chlorocarbons. The less than complete success of these procedures resulted from the lack of application of reaction engineering principles that were not widely known at that time. Now these are available and can be used to overcome some of the past difficulties. Using reaction engineering principles, catalytic metals were chosen whose chloride salts do not decompose easily. These are brought in close contact to the alkali carbonates to make the diffusion length to the solid-solid interface short. The carbonates are consumable reactants that regenerate the catalyst during operation and also act as a support for the catalytic metals. The reactor also works as a "dry scrubber" separator because the heteroatoms, as their salts, are removed with the moving solid. Integration of the rate equation shows much better performance from countercurrent moving-bed operation compared with that of cocurrent processing. For very toxic chemicals, an oxygen-fed, closed-loop, and below atmospheric pressure operating system can achieve almost complete conversion. The cycle gas is made from the small inert content of the technical oxygen and from the air that leaks into the system. To keep the contents of inert gas and other inert ingredients of the cycle at steady state, a small stream is released from the cycle. The release constitutes 0.025% of the cycle volume.