文摘
Sodium carbonate and carbonate minerals have been used in situ toneutralize the HCl generatedduring oxidation of chlorocarbons. The less than complete successof these procedures resultedfrom the lack of application of reaction engineering principles thatwere not widely known atthat time. Now these are available and can be used to overcomesome of the past difficulties.Using reaction engineering principles, catalytic metals werechosen whose chloride salts do notdecompose easily. These are brought in close contact to the alkalicarbonates to make thediffusion length to the solid-solid interface short. Thecarbonates are consumable reactantsthat regenerate the catalyst during operation and also act as a supportfor the catalytic metals.The reactor also works as a "dry scrubber" separator becausethe heteroatoms, as their salts,are removed with the moving solid. Integration of the rateequation shows much betterperformance from countercurrent moving-bed operation compared with thatof cocurrentprocessing. For very toxic chemicals, an oxygen-fed, closed-loop,and below atmospheric pressureoperating system can achieve almost complete conversion. The cyclegas is made from the smallinert content of the technical oxygen and from the air that leaks intothe system. To keep thecontents of inert gas and other inert ingredients of the cycle atsteady state, a small stream isreleased from the cycle. The release constitutes 0.025% of thecycle volume.