Cold flow model of dual fluidized bed: A review

Abstract

Gasification in dual fluidized bed gasifier (DFBGs) has proven itself as a promising technology. Apart from gasification, dual fluidized bed (DFB) technology has also been utilized for CO2 capture-chemical looping combustion (CLC), calcium looping (CaL) and adsorption enhanced reforming (AER). Although pilot plants applying these technologies are available, still need improvement to be commercially viable. Fundamentally, the performance of the reactor depends upon the fluid dynamics within the reactor. So cold flow models (CFMs) are widely used in order to study the process fundamentals such as: pressure drop, solid fraction and solid circulation rate, to improve the operation and tackle the problem by troubleshooting. This paper outlines the application of scaling relationships to realize the hydrodynamic similarity among the industrial scale plant, the laboratory scale and CFMs of dual fluidized bed (DFB). Moreover, the occurring fluidization regimes and the stable operating regions in the cold model of DFB have been explored by reviewing the existing data in the literature. The pressure profiles, solid fraction profiles and the solid circulation rate obtained from the existing studies are presented and discussed together with the effect of the parameters influencing their behavior.