Portland cement as a regenerable sorbent for the removal and recovery of SO/sub 2/ in the fluidized-bed combustion of coal

Conference · Sun Mar 01 04:00:00 EST 1981

OSTI ID:6155495

Steinberg, M; Yoo, H J; McGauley, P J

A sorbent which solves most of the problems for the removal of sulfur in the Fluidized Bed Combustion (FBC) of Coal has been developed. The sorbent is based on the use of calcium silicate which is contained in commercial grade Portland cement. The Portland cement is hydrated and agglomerated in a drum type pelletizer to form particles in the size range required for operating FBC units. These are subsequently cured and dried into hard durable pellets which can be directly used in the FBC. Pellet formation is a low energy process. Laboratory measurements have been obtained on the rate and capacity of absorption of SO/sub 2/ using simulated combustion gases. The sulfated cement pellets have also been regenerated to reform the sorbent and produce a concentrated SO/sub 2/ gaseous stream. In the overall process, the SO/sub 2/ will be reduced to sulfur for disposal or for market use. The cement sorbent has been put through more than 10 cycles of absorption and regeneration with little loss of reactivity. Laboratory attrition studies indicate minimal loss of sorbent (less than 3% per cycle). The sorbent is effective up to a temperature of over 1000/sup 0/C in FBC, which would significantly improve the overall power production efficiency of the plant. Portland Cement Type III (PC III) sorbent can readily remove 90% of the sulfur from a high sulfur (4%) coal. Thermodynamic and laboratory pressurized TGA tests indicate that PC III will be effective in pressurized fluidized bed combustion (PFBC) units since the sulfation rate is not decreased under higher CO/sub 2/ partial pressures compared to limestone. The equilibrium concentration of SO/sub 2/ on regeneration of PC III is much higher than for limestone. Another important advantage of Portland cement sorbent is that it is produced under quality controlled conditions and is not subject to the variability of natural deposits of limestone with respect to composition, reactivity and capacity for SO/sub 2/ removal.

• Research Organization: Brookhaven National Lab., Upton, NY (USA)
• DOE Contract Number: AC02-76CH00016
• OSTI ID: 6155495
• Report Number(s): BNL-29303; CONF-8105106-1; ON: DE81027304
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010400 -- Coal
Lignite
& Peat-- Processing
42 ENGINEERING
421000* -- Engineering-- Combustion Systems
BUILDING MATERIALS
CARBONACEOUS MATERIALS
CEMENTS
CHALCOGENIDES
CHEMICAL REACTIONS
CHEMISORPTION
COAL
COMBUSTION
COMBUSTORS
DATA
ECONOMICS
ENERGY SOURCES
EXPERIMENTAL DATA
FLUIDIZED-BED COMBUSTION
FLUIDIZED-BED COMBUSTORS
FOSSIL FUELS
FUELS
INFORMATION
MATERIALS
NUMERICAL DATA
OXIDATION
OXIDES
OXYGEN COMPOUNDS
PERFORMANCE
PORTLAND CEMENT
SEPARATION PROCESSES
SORPTION
SORPTIVE PROPERTIES
SULFUR COMPOUNDS
SULFUR DIOXIDE
SULFUR OXIDES
SURFACE PROPERTIES
THERMOCHEMICAL PROCESSES