Condensate from a two-stage gasifier

Condensate, produced when gas from downdraft biomass gasifier is cooled, contains organic compounds that inhibit nitrifiers. Treatment with activated carbon removes most of the organics and makes the condensate far less inhibitory. The condensate from an optimised two-stage gasifier is so clean that the organic compounds and the inhibition effect are very low even before treatment with activated carbon.

The moderate inhibition effect relates to a high content of ammonia in the condensate. The nitrifiers become tolerant to the condensate after a few weeks of exposure. The level of organic compounds and the level of inhibition are so low that condensate from the optimised two-stage gasifier can be led to the public sewer.