Foster Wheeler’s Solutions for Large Scale CFB Boiler Technology: Features and Operational Performance of Łagisza 460 MWe CFB Boiler

Abstract

During recent years, once-through supercritical (OTSC) CFB technology has been developed, enabling the CFB technology to proceed to medium-scale (500 MWe) utility projects such as Łagisza Power Plant in Poland owned by Poludniowy Koncern Energetyczny SA. (PKE), with net efficiency nearly 44%. Łagisza power plant is currently under commissioning and has reached full load operation in March 2009. The initial operation shows very good performance and confirms, that the CFB process has no problems with the scaling up to this size. Also the once-through steam cycle utilizing Siemens’ vertical tube Benson technology has performed as predicted in the CFB process. Foster Wheeler has developed the CFB design further up to 800 MWe with net efficiency of ≥45%.

Foster Wheeler’s circulating fluidized bed (CFB) boiler technology meets today’s market demand for utility-size boilers with capability to fire broad range of fuel qualities from low-grade high-ash fuels, good quality bituminous and anthracite coals to various biomass and waste fuels. The high efficiency CFB boilers are designed for firm emission performance and high reliability.

The proven high efficiency circulating fluidized-bed (CFB) technology offers a good solution for CO₂ reduction both in repowering of coal fired power plants and in greenfield power plants. CFB technology with its excellent fuel flexibility offers the opportunity to further reduce CO₂ emissions by co-combusting coal with biomass. FW has also developed CFB gasification technology for biomass applications. An example of this technology is gasification of biomass with a pressurized gasifier to produce syngas, which can be used for biodiesel production to address the reduction of CO₂ emissions from vehicles.

Carbon capture and storage (CCS) offers the potential for major cuts in CO₂ emissions of fossil fuel-based power generation in the fairly short term, provided that it gains public acceptance, the required regulatory framework is created and emission trading mechanisms or other incentives can provide solid return on the major investments required. Oxy-fuel combustion is one of the identified main CCS technology options, and Foster Wheeler is developing its CFB combustion technology for oxy fuel combustion to provide a CCS-ready solution. Foster Wheeler is currently developing Flexi-Burn™ CFB concept, which enables the plant to be operated either with or without carbon capture. This paper presents the existing status of CFB technology in respect of boiler efficiency and fuel flexibility. The main advantages of the CFB technology for oxyfuel combustion and a development plan for the Flexi-Burn™ CFB will be presented.