Experimental investigation of high-temperature, short residence-time calcination and sulfation of limestone and dolostone sorbents

Conference · Sat Dec 31 04:00:00 EST 1994

OSTI ID:254705

Hu, Naiya; Miller, S F; Scaroni, A W ^[1]

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1. Penn State Univ., University Park, PA (United States)

Sulfur dioxide emissions from coal-fired utility boilers and furnaces continue to be of significant regulatory concern. One approach to reducing these emissions that has received considerable attention is the injection of dry, pulverized sorbent (limestone or dolostone) into the combustion chamber. This technology has been applied to conventional coal-fired utility boilers and is considered to be a good candidate for use in coal-fired heat engine applications. During the process, the injected limestone or dolostone particles are rapidly heated by the hot combustion gases and calcined by the reactions CaCO{sub 3} {yields} CaO + CO{sub 2} and CaMg(CO{sub 3}){sub 2} {yields} CaO + MgO + 2CO{sub 2}, respectively. The CaO produced then reacts with SO{sub 2} and excess O{sub 2} in the combustion gases to form CaSO{sub 4}. Experimental data on the rates of calcination, sintering and sulfation have been reported by Borgwardt and others. The physical structure of the calcined sorbents has also been investigated and a number of models have been developed describing the calcination and sulfation processes. The primary application of dry sorbent injection is to conventional coal-fired utility boilers. The sorbent particle size used is either small (in the range of 1 to 30 {mu}m) in pulverized coal applications or large (in the range of 0.25 to 1 mm) for fluidized-bed applications. Few investigations have been carried out using 30 to 100 {mu}m particles, which is the size range of interest for coal-fired heat engine applications. This study investigated the calcination and sulfation behavior of three different sorbents (two limestones and one dolostone) in the size range from 37 to 105 {mu}m. The time required for heating and calcination, the effect of the calcination process on sulfation behavior, and the effect of sorbent type on sulfation behavior were of primary interest.

• OSTI ID: 254705
• Report Number(s): CONF-940813--
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
20 FOSSIL-FUELED POWER PLANTS
AIR POLLUTION CONTROL
CALCINATION
CALCIUM CARBONATES
CHEMICAL PROPERTIES
COAL
COMBUSTION
FOSSIL-FUEL POWER PLANTS
LIMESTONE
PARTICLE SIZE
SINTERING
SORPTION
SORPTIVE PROPERTIES
SULFATION
SULFUR DIOXIDE
TIME DEPENDENCE