How can catalytic converters be used in electric cooking appliances to reduce air pollutants?
Catalytic converters are a very effective technology to reduce fumes emitted from foodstuffs during cooking They can reduce emissions from most types of oven, including unpleasant smells as well as suspended grease particles.
Along with the obvious benefit of pollution reduction, installing this technology in your ovens can help to get them certified for ventless operation.
So how is this technology applied?
Firstly, let’s look at catalysis. This is a branch of chemistry where certain chemicals known as ‘catalysts’ are used in order to encourage or promote reactions between other chemicals. A key point to appreciate is that the catalysts themselves are not consumed by the reactions; they merely help them along. Therefore, a catalyst can theoretically last forever.
The name ‘catalytic converter’ is applied to a practical device which has been designed to make use of catalytic technology i.e. it enables the benefits of catalysis to be obtained in real-life situations.
Various chemical reactions can be promoted by catalysis, but where the aim is to improve air quality the most important reaction is oxidation. The majority of air pollutants are organic in nature (i.e. they contain carbon) and can be oxidised into harmless substances such as carbon dioxide and water.
Most oxidation catalytic converters use coatings based on platinum and/or palladium, which are effective at temperatures as low as 200oC. The structural part of a catalytic converter is known as a ‘substrate’, the main purpose of which is to provide a large surface area onto which the catalytic coating can be applied.
Effectiveness of Catalytic Converters
Catalytic converters are very effective at oxidising most of the organic gases and condensable particulate matter components of cooking fumes to carbon dioxide and water. These reactions have double benefits: they improve air quality and also release heat energy from the fumes which would otherwise be wasted.
In order for the catalytic converter to be effective, the temperature of the gas passing through it needs to be at least 200oC therefore this technology is most suited to enclosed cooking equipment such as ovens, charbroilers, fryers, chargrills and roasters. The most popular applications for catalytic converters in the commercial sector are rapid-cook combination ovens, as well as conveyor and pizza ovens. In the domestic sphere they are frequently fitted to high-end pyrolytic self-cleaning ovens to minimise the unpleasant fumes emitted during the cleaning cycle.
- A vital consideration for catalytic converters used in cooking appliances which involve gas recirculation is that the catalytic coating must be very well adhered to the substrate, otherwise it could flake off and contaminate the food.
- The catalytic converter must also be made of materials which do not corrode in the moist atmosphere present in a cooking appliance.
- Finally, cooking equipment equipped with catalytic converters must only be cleaned using approved chemicals, otherwise this may result in damage to the catalytic converter. Caustic cleaning products must never be used.
Whitebeam are happy to advise customers on which is the most suitable solution for their specific application based on our many years of experience in this field.