Fluidized bed agglomerator

Wang Y., Wei F., Luo G., Yu H., Gu G. The large-scale production of carbon nanotubes in a nano-agglomerate fluidized-bed reactor. Chemical Physics Letters, 2002,364, 568-572. 

Figure 4.26 shows an agglomerating fluidized-bed gasifier developed by KRW. In the KRW process, limestone can be injected with the coal for sulfur capture. The KRW process is employed in a 100 MW IGCC Pinon Pine Plant near Reno, NV. Due to some difficulties in the hot gas filtering section, the plant could not be started up successfully.1... 

A good example of continuous particle separation is the industrial application in the ash-agglomerating fluidized bed gasifier. The ash remained from gasification of coal is agglomerated into bigger and denser agglomerates and is continuously removed from the fluidized... 

The current DOE CCT projects which may be built include KRW and Tampella/U-Gas coal gasification systems (64). These two similar agglomerating fluidized-bed co gasification processes are being considered for IGCC application based on air-blown operation and advanced hot gas clean-up. 

Haldipur, G., Schmidt, D and Smith, K. (1988) A 50-month gasifier mechanistic study and downstream unit process development program for the pressurized ash-agglomerating fluidized-bed gasification system, final report volume II. Technical Report, KRW Energy Systems Inc. 

Figure 6.33 Agglomerating fluidized-bed (AFB) gasifier (HP - high pressure).

A 50-Month Gasifier Mechanistic Study and Downstream Unit Process Development Program for the Pressurized Ash-Agglomerating Fluidized-Bed Gasification System, Final Report Volume II. Tech. Rep., KRW Energy Systems Inc. 

Kuwagi, K., K. Takano and M. Horio, The effect of tangential lubrication by bridge liquid on the behavior of agglomerating fluidized beds, Powder Technology, 113, pp.287-298,2000... 

Process development on fluidized-bed pyrolysis was also carried out by the ConsoHdation Coal Co., culminating in operation of a 32 t/d pilot plant (35). The CONSOL pyrolysis process incorporated a novel stirred carbonizer as the pyrolysis reactor, which made operation of the system feasible even using strongly agglomerating eastern U.S. biturninous coals. This allowed the process to bypass the normal pre-oxidation step that is often used with caking coals, and resulted in a nearly 50% increase in tar yield. Use of a sweep gas to rapidly remove volatiles from the pyrolysis reactor gave overall tar yields of nearly 25% for a coal that had Eischer assay tar yields of only 15%. 

All the foregoing pertains to sohds of approximately the same physical characteristics. There is evidence that sohds of widely different characleristics wih classify one from the other at certain gas flow rates [Geldart, Baeyens, Pope, and van de Wijer, Powder Technol., 30(2), 195 (1981)]. Two fluidized beds, one on top of the other, may be formed, or a lower static bed with a fluidized bed above may result. The latter frequently occurs when agglomeration takes place because of either fusion in the bed or poor dispersion of sticl feed solids. 

Fluidized beds 0.1 to 2 Low (agglomerated) 100-900 kg batch to scale, difficult for inorganic salts. 

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