Plasma Catalysis for the Abatement of Halomethanes

The destruction of chlorofluorocarbons (CFCs) which are ozone-depleting substances banned by the Montreal Protocol represents a particular technical challenge. Very high temperatures ( 1,250°C) provided by high-temperature incineration and thermal plasma torches are needed to destroy the CFCs safely without the formation 

It should be noted that the photon energy and flux emitted from these discharges are not sufficient to explain the enhancement in destruction by photocatalysis. While Ti02 is found to be effective in more than doubling the CFC-12 destruction efficiency, the NaX zeolite catalyst which has no effect in enhancing the CFC-12 destruction (Fig. 6.2) reduces the NOx formation by more than a factor of two compared with the use of a plasma discharge alone. Ideally in plasma catalysis, we wish to achieve both enhancement in destruction and minimisation of unwanted by-products. 

To gain further insight into how the plasma and catalyst interact in this system, we performed some characterisation of the catalysts after a period of treatment in the plasma environment using BET (Brunauer, Emmett and Teller) surface area analysis, SEM (scanning electron microscopy) investigation of the surface morphology, elemental analysis and ATR-IR (attenuated total reflection Infrared) spectroscopy 

Barium 0.5 ml 0.5 ml Titanate HZSM-5 Calcined Beads HZSM-5 

Three experiments were undertaken. In the first, only a plasma was used to destroy the DCM. After an initial rise in the percentage destruction, the destruction remained approximately constant at 20% for temperatures 250 C. For conventional thermal catalysis, there is litde destruction for temperatures 200°C when 

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