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Main elements and key objectives


Objective: To develop a high-efficiency FLEXI BURN design for a CFB boiler operating with sliding pressure once through steam cycle and air-/oxygen-firing modes by

a) carrying out RTD work to extend the existing elementary knowledge of air-firing to oxygen-firing in a circulating fluidized bed (CFB) boiler that is in a CO2 - H2O- rich atmosphere differing considerably from that of normal combustion with air

b) extending and validating design tools for a CFB boiler based on elementary knowledge and experimental data from pilot plants and the commercial-scale field measurements

Technology demonstration

Objective: To demonstrate flexible air- and oxygen-firing with CO2 capture at a large pilot-scale CFB and verify the operation of a commercial-scale high-efficiency SC-OTU CFB in order to produce appropriate scale-up information by

a) demonstrating air/oxy fl exible CFB operation on the 30 MWth scale (air- and oxygen-firing) with different kinds of local fuels and CO2 capture

b) test campaigns at the world’s first and the largest high efficiency SC-OTU CFB of 460 MWe (air-firing)

Concept development

Objective: To develop the overall plant concept for the reliable, safe and economical carbon capture with advanced circulating fluidized bed combustion (CFB) technology that can operate under air- and oxygen-firing mode, enabling CO2 separation and capture for geological storage by

a) integrating a air/oxy flexible CFB boiler with an air separation unit (ASU) and CO2 processing unit (CPU) in order to create an optimized overall power plant concept

b) verifying the feasibility and readiness for the utilization of the technology within different regions of the EU

Overall Target

To create the readiness to start engineering of a commercial scale demonstration of an air / oxy flexible CFB power plant with CCS that is applicable to various local conditions within the EU by the end of the project.

Development and demonstration on multiple scales - Principle of demonstration steps towards air/oxy flexible CFB concept.

The AIR/OXY FLEXIBLE CFB concept has a set of important advantages:

  • Fuel flexibility in order to decrease dependency on imported coals and in order to improve power plant economics especially with CCS operation
  • Operational flexibility in order to apply air-firing and oxygenfiring with CO2 capture
  • Lower NOx production due to reduced and more uniform furnace temperature profiles, and lower SOx concentration in flue gases due to in-furnace capture, thus reducing the need for downstream flue gas cleaning
  • New methods to control power plant with air separation unit (ASU) and CO2 capture
  • Overall concept for phased transition into CCS technology with minimised risks through high efficiency air-oxy flexible CFB combustion
  • Lower specific CO2 emissions from the reduced consumption of fuel due to the intrinsic high efficiency of the technology. In addition, by substituting e.g. 20% of coal input with renewable fuels, CO2 emissions can further be reduced by 15-20%.
  • Provides utilities an attractive alternative to take into use the new technology and decommission old capacity with lower efficiency and poorer emission performance

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Additional information
Antti Tourunen
+358 20 722 2718
FLEXI BURN CFB | EU FP7 | 2009 - 2012