AN ALSTOM VISION OF FUTURE CFB TECHNOLOGY BASED POWER PLANT CONCEPTS

摘要

ALSTOM is actively working to develop circulating fluidized bed (CFB) based technologies to continue to reduce costs and mitigate CO_2. Advanced ALSTOM concepts include "the oxygen-fired CFB," which uses pure oxygen plus recirculated flue gas (mainly CO_2) as a combustion medium, resulting in a flue gas stream with a high CO_2 concentration. Consequently, CO_2 can be separated from the flue gas stream relatively easily. As such, this technology is geared toward CO_2 mitigation. Another advancement, "the circulating moving bed (CMB™)" system, uses a novel heat exchanger design that heats the energy cycle working fluid to the high temperature levels required for advanced power generation systems. The CMB™ combustion system is also an enabling technology for hydrogen production and CO_2 capture from combustion systems utilizing innovative chemical looping gasification and syngas decarbonization. Chemical looping is another development path towards CO_2 mitigation. In ALSTOM''s processes, oxygen (from air) is transported by a solid oxygen carrier for combustion or gasification of the fuel. CO_2 is captured in a separate chemical loop in the gasification process. The process can be used to produce nearly pure CO_2 and steam for a Rankine cycle; or synthesis gas or hydrogen with CO_2 capture for IGCC''s, fuel cells, or industrial use. This paper will discuss ALSTOM''s latest work and the technical and economic implications of these advanced CFB-based systems. These advanced power generation units can be built from proven fluid bed design features and systems and the same processes supporting current-state technology enable rational development of future-state power generation and CO_2 capture.