Cyclone gasifier for biomass. Preliminary investigations

Aiming at the design of a 20 MW as fired slagging cyclone gasifier for biomass, it has been investigated how biomass can or have to behave in such a device. This has included calculations for the slag flow, the heat loss, the gasification limits for char sitting in the molten slag surface, and fluid dynamics calculations for the gas and particle flows in a test case and in a proposed design. It has been found that it is unlikely that the char sitting in the slag surface can gasify at a rate equaling the feeding rate unless the cyclone is very large, that a high amount of char therefore has to stay in suspension somewhere in the cyclone and for a long time and that this may lead to a substantial carry over for the proposed design.