Hand-fired log stoves need an effective and at the same time economically feasible emission reduction in order to be able to comply with future emission limits.
Catalytic converters integrated into furnaces are a very good and cost-effective way to significantly reduce emissions from incomplete combustion (CO, hydrocarbons).
In addition to these gaseous and oxidisable pollutants, however, there is the problem of dusty pollutants being emitted. So far, only about 20 % of the dust produced could be reduced by oxidative catalytic degradation directly at the catalyst without adaptation and conversion of the furnace.
The new solution from Blue Fire GmbH provides for a two-stage catalyst system. Two catalysts arranged in the furnace in such a way that first the dust emissions are reduced and then the gaseous components of the emissions are oxidised.
In the first stage, the particles with a high soot content are first retained. In the next step, a part of the carbonaceous components is oxidised in stage 1 and then discharged again by the flow from stage 1. This prevents blockage of stage 1. In the second catalyst stage, the gaseous pollutants CO and hydrocarbons are reduced.
In order to significantly increase the dust reduction of integrated catalysts in wood firing systems, a two-stage catalyst module developed by the company Blue Fire GmbH was integrated into a simple stove of the lower price segment and tested by the DBFZ Deutsches Biomasseforschungszentrum gemeinnützige GmbH under simulated natural draught conditions. With this two-stage catalyst module, the pollutants carbon monoxide (CO) were reduced by more than 80 %, hydrocarbons (VOC) by up to 70 % and dust by more than 50 %.
The two-stage catalyst module is available and can be integrated into a wide variety of different stove models. The measurement data is freely available for download at https://data.mendeley.com/datasets/2xcp6rytgw/1 and was presented at the 9th Separator Expert Meeting on 21.03.2018 in Leipzig.