Fluidized-bed ash-agglomeration gasifier
Current procedure with most fluidized-bed gasifiers is to limit ash buildup by continually discharging a portion of the fluidized bed. Inasmuch as the ash content frequently cannot exceed 50% in the bed, this continuous discharge procedure can result in a carbon loss equivalent to the percentage ash in the feed. This test program has shown conclusively that high-ash-content agglomerates can be selectively removed on a steady-state, long-term basis from a dense-phase fluidized bed of high carbon content. The use of fines recycle further improves the carbon utilization, and carbon gasification efficiencies over 95% are obtainable. In general, agglomerates of 65% to 95% ash content were produced from a dense-phase fluidized bed with the average bed ash content between 22% and 28%. Higher bed temperatures produce higher ash-content agglomerates for a given feed particle size range. It appears that the average feed particle size affects the bed temperature at which aglomerates begin to form. As the particle size decreases, the required bed agglomerating temperature rises. The role of the ferrous aluminum silicate eutectic in agglomerate formation was explored. It is possible that this eutectic material is helpful in promoting the formation of ash agglomerates. The work was conducted at near atmospheric pressure. Further work at high pressures should be done to adequately define the operating conditions necessary for agglomerate production when applied to pipeline gas processes.
- Research Organization:
- Inst. of Gas Tech., Chicago
- OSTI ID:
- 6529684
- Journal Information:
- Coal Process. Technol.; (United States), Vol. 3
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ASHES
AGGLOMERATION
HYGAS PROCESS
AGGLOMERATING ASH PROCESS
ALUMINIUM SILICATES
COAL GASIFICATION
FLUIDIZED BED
IRON COMPOUNDS
RECYCLING
ALUMINIUM COMPOUNDS
GASIFICATION
OXYGEN COMPOUNDS
RESIDUES
SILICATES
SILICON COMPOUNDS
SNG PROCESSES
THERMOCHEMICAL PROCESSES
TRANSITION ELEMENT COMPOUNDS
010404* - Coal
Lignite
& Peat- Gasification