The BETH Tar Electrostatic Precipitator (ESP) is a specialized version of the Wet ESP used mainly in gasification plants. The BETH Filtration product is particularly popular with providers of biomass gasification.

The operator of a wood gasification plant in Dortmund also chose to install the Tar ESP to make the gasification process a »safe thing« for the turbine downstream of the filter. The ESP protects the turbine by removing tars from the gas. Cramped quarters on location provided quite a challenge for the BETH engineers. The product made in Lübeck had to be tailor-made to fit exactly into its slot in the factory hall.

The filter is designed for temperatures of up to 100° C with a volume flow of 1,600 Am³/h. The pure gas dust content is 10 mg/m³. The raw gas enters the ESP low on one side. A gas distribution device below the electrostatic field creates an even flow profile, which is a necessary prerequisite for the best possible filtration results. The filter area consists of collection electrodes arranged in a honeycomb pattern. The tar mist is electrically charged and attracted to the collection electrodes, then attaches to the condensate film and drips off. The separated condensate is pumped into a collecting container.

In the past, the main problem with biomass gasification was the generally poor gas quality, especially the high gas and dust content. Using a BETH Tar ESP solved this problem for the customer in Dortmund.