We offer a range of products which are designed specifically for a variety of different applications. Whether you are interested in reducing emissions from electric cooking, solid fuel cooking, domestic biomass or large-scale biomass, we have a product to suit your needs.
We can supply a range of catalytic converters for oxidation and Selective Catalytic Reduction (SCR), as well as SCR Dosing systems. Here is a summary of each:
Ceramic honeycomb substrates are normally made from a special type of ceramic material known as ‘cordierite’. Liquid cordierite is extruded through a mould and then fired so that it dries out and becomes hard. By using different moulds, various size substrates can be extruded and the size of the channels (or cells) can also be varied. Because tooling is required, ceramic honeycombs are best suited to medium or large volume requirements unless a standard size can be used. Ceramic honeycombs are generally the most economical option for consumer appliances such as biomass stoves and pyrolytic self-cleaning ovens.
Metal honeycomb substrates are made from extremely thin metal foil, typically with a thickness of just 0.05mm. By comparison the walls of a ceramic substrate may be four times thicker. For this reason, metal substrates offer less resistance to gas flow and therefore can accommodate a given flow rate with a lower pressure drop than an equivalent ceramic substrate.
Knitted wire is often used to make grease filters for cooking appliances but these only trap liquids and solids and require frequent cleaning to prevent them becoming blocked. Some ovens incorporate a separate catalytic converter based on the conventional honeycomb structure to oxidize pollutants in the gas phase against which a grease filter is ineffective. However, by applying a catalytic coating to a knitted wire filter it can function as a catalytic converter too.
Reticulated ceramic foam is a relatively new alternative for making the substrates which are at the core of catalytic converters. Reticulated ceramic foam substrates have an irregular appearance like a sponge, which means that they act as a filter as well as a catalytic converter.
SCR Catalytic Converters
As with all catalytic converters, the SCR variety consists of a substrate, a catalytic coating and a housing.
The job of the substrate is to provide the necessary surface area for the chemical reactions to occur whilst also complying with the pressure-drop requirements of the system. Another consideration is that the channels through the substrate must not be too small otherwise they could get blocked up with ash or chaff. Whitebeam uses a range of substrate materials including metal foil, glass fibre and extruded ceramics. Many options of cell density are available too.
Selective Catalytic Reduction Dosing Systems
The purpose of the dosing system is to inject the correct quantity of a reductant into the flue gas, depending on the amount of NOx present and the flue gas temperature.