Dual Fluidized Bed Gasifizer
The biomass conversion into syngas takes place in a Dual Fluidized Bed (DFB) Gasifier. The DFB gasification system consists of two interconnected reactors, the gasifier and the oxidizer. The char produced, other residues and part of the bed material are transported to the combustor where they react with air to produce heat. The hotter bed material returns to the gasifier, serving as an external heat source for the endothermic pyrolysis and steam gasification reactions, leading to higher carbon conversion rate and thermal efficiency. The raw syngas is filtered at gasifier exit temperature and the already secured low content of heavy tars along with hydrocarbon gases are catalytically reformed in oxygen or steam atmosphere. Clean syngas is issued from the acid gas removal unit, which includes a scrubber and adsorbents. A DFBG system ensures extended fuel flexibility, syngas of high quality with controllable levels of tar, complete fuel conversion and optimal heat integration and steam generation. No special biomass pre-treatment unit in addition to simple size reduction is required as this specific gasifier type can handle quite effectively a wide range of raw feedstock. Within BioSFerA, the operation of the DFB gasifier with various biomass feedstocks will be demonstrated. There will be a special focus to co-process wood residues with targeted wastes. Moreover, the inert-material and all operational parameters of the DFB will be fine-tuned to the downstream requirements of the BioSFerA concept.