Project Maxau — First Application of Hybrid CFB Technology by Austrain Energy & Environment

Abstract

As a worldwide supplier of fluidized bed combustion plants the reference list of Austrian Energy & Environment comprises more than 80 fluidised bed boilers over a wide capacitiy range with different kinds of fuel such as coal, biomass, sludges, RDF or various industrial wastes.

Actually two types of CFB Boilers were supplied by AE&E: On the one hand the “classical”, conventional Power Fluid^® CFB with cooled furnace, cyclone, cross-over duct or vertical convection pass to be employed for combustion of conventional fuels such as hard coal, lignite, biomass and sludge et al. The chlorine content of these fuels is as a rule lower than 0.1% in dry matter.

On the other hand the especially developed CFB for the combustion of refuse derived fuel (RDF) with the special features of an adiabatic primary loop with controlled heat extraction in an external bed material cooler, a toroid shaped adiabatic post combustion chamber downstream the primary cyclone. This combustion part is followed by a well known boiler concept of a classical waste incineration consisting of two radiation passes and a horizontal convection pass with hanging superheater and evaporation bundles.

Live steam temperatures up to 470°C (450°C) with fuel chlorine contents of 1.2% (1.5%) in dry matter can be accepted with this concept.

Market development in the last years showed a limited access to a particular segment with these two CFB concepts. This market segment consists of co — combustion plants firing biomass and / or conventional fuels with addition of RDF or production residues — in the majority of cases in the pulp and paper industry. The chlorine content in these fuel mixtures is typical around 0.2% in dry matter, with often missing sulphur content and the required live steam temperatures are between 500°C and 520°C.

Out of this AE&E developed a “combined” CFB-concept with the brand name Power Fluid^® Hybrid.

The presentation will provide a detailed description of the special features of the Hybrid technology by means of the Maxau plant.