Organic compounds such as bromobutane have long been known to be damaging to the atmosphere and to human health. This process attempts to serve an unmet need for a cheap and effective process for dealing with these hazardous chemicals before they are emitted into the atmosphere.
Catalytic oxidation - when oxygen is used from the atmosphere burns off the prejudicial compounds with the help of a catalyst.
Catalysts, in this process, provide a number of advantages. On the one hand, they reduce the energy necessary for burning the contaminant compounds and, on the other, each type of contaminant gas has its specific catalyst.
Nevertheless, for the combustion process to be effective, the catalysts have to comply with a series of requirements.
Researchers, from the Leioa campus of the University of the Basque Country, experimented with zeolite catalysts. The results obtained showed the canals present within the structure of the zeolites played a significant role in the reaction.
The zeolite is the compound that initiates the reaction during the active phase. The active phase is also the stage in which the contaminant gas enters the pores of the catalyst.
Water, carbon dioxide and a halogenated compound are produced as a result of this reaction.
This last product is subsequently neutralised in a shower of caustic soda. Thus, only H20 and CO2 are liberated into the atmosphere.
Zeolites may have parallel or intercrossing; and it would seem that the zeolites with the second structure are better for this type of reaction.
This is because an obstacle in a zeolite structure of parallel canals will prevent the gas passing through while this does not happen in the case of zeolites with a structure of intercrossing canals.
But apart from the type of canal there are other characteristics that influence the reaction.
The amount of contaminant gas is critical as the quantity of catalyst used and the temperature of combustion determines eventual yield.
Temperature, in fact, is one of the most important parameters. The lower the temperature of combustion, the less will be the energy spent.
The researchers are currently trying to establish the durability of the catalysts, i.e. to ascertain when active phase compound has to be replaced or renewed so that the "cleaning," of the volatile organic compounds continues to operate.