Fluidized-bed ash-agglomeration gasifier

Journal Article · Sat Jan 01 04:00:00 EST 1977 · Coal Process. Technol.; (United States)

OSTI ID:6529684

Sandstrom, W A; Rehmat, A G; Bair, W G

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), Journal Name: Coal Process. Technol.; (United States) Vol. 3; ISSN CPRTD
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010404* -- Coal
Lignite
& Peat-- Gasification
AGGLOMERATING ASH PROCESS
AGGLOMERATION
ALUMINIUM COMPOUNDS
ALUMINIUM SILICATES
ASHES
COAL GASIFICATION
FLUIDIZED BED
GASIFICATION
HYGAS PROCESS
IRON COMPOUNDS
OXYGEN COMPOUNDS
RECYCLING
RESIDUES
SILICATES
SILICON COMPOUNDS
SNG PROCESSES
THERMOCHEMICAL PROCESSES
TRANSITION ELEMENT COMPOUNDS