skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Low temperature SO{sub 2} removal with solid sorbents in a circulating fluidized bed absorber. Final report

Abstract

A novel flue gas desulfurization technology has been developed at the University of Cincinnati incorporating a circulating fluidized bed absorber (CFBA) reactor with dry sorbent. The main features of CFBA are high sorbent/gas mixing ratios, excellent heat and mass transfer characteristics, and the ability to recycle partially utilized sorbent. Subsequently, higher SO{sub 2} removal efficiencies with higher overall sorbent utilization can be realized compared with other dry sorbent injection scrubber systems.

Authors:
;
Publication Date:
Research Org.:
Cincinnati Univ., OH (United States). Dept. of Civil and Environmental Engineering
Sponsoring Org.:
USDOE, Washington, DC (United States)
OSTI Identifier:
39135
Report Number(s):
DOE/PC/91336-T6
ON: DE95009347; TRN: 95:003399
DOE Contract Number:
FG22-91PC91336
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: 10 Oct 1994
Country of Publication:
United States
Language:
English
Subject:
01 COAL, LIGNITE, AND PEAT; 20 FOSSIL-FUELED POWER PLANTS; 42 ENGINEERING NOT INCLUDED IN OTHER CATEGORIES; SULFUR DIOXIDE; REMOVAL; FLUE GAS; DESULFURIZATION; ADSORBENTS; DESIGN

Citation Formats

Lee, S.K., and Keener, T.C. Low temperature SO{sub 2} removal with solid sorbents in a circulating fluidized bed absorber. Final report. United States: N. p., 1994. Web. doi:10.2172/39135.
Copy to clipboard
Lee, S.K., & Keener, T.C. Low temperature SO{sub 2} removal with solid sorbents in a circulating fluidized bed absorber. Final report. United States. doi:10.2172/39135.
Copy to clipboard
Lee, S.K., and Keener, T.C. Mon . "Low temperature SO{sub 2} removal with solid sorbents in a circulating fluidized bed absorber. Final report". United States. doi:10.2172/39135. https://www.osti.gov/servlets/purl/39135.
Copy to clipboard
@article{osti_39135,
title = {Low temperature SO{sub 2} removal with solid sorbents in a circulating fluidized bed absorber. Final report},
author = {Lee, S.K. and Keener, T.C.},
abstractNote = {A novel flue gas desulfurization technology has been developed at the University of Cincinnati incorporating a circulating fluidized bed absorber (CFBA) reactor with dry sorbent. The main features of CFBA are high sorbent/gas mixing ratios, excellent heat and mass transfer characteristics, and the ability to recycle partially utilized sorbent. Subsequently, higher SO{sub 2} removal efficiencies with higher overall sorbent utilization can be realized compared with other dry sorbent injection scrubber systems.},
doi = {10.2172/39135},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Mon Oct 10 00:00:00 EDT 1994},
month = {Mon Oct 10 00:00:00 EDT 1994}
}
Copy to clipboard
Technical Report:
View Technical Report (8.54 MB)
DOI:  10.2172/39135
Save / Share:
Export Metadata
Save to My Library
You must Sign In or Create an Account in order to save documents to your library.

  • ;
    The construction of a bench-scale Circulating Fluidized Bed Absorber (CFBA) unit has been completed, and system calibrations have already been performed. In addition, as a novel method injecting water into CFBA, a toroidal-shaped nozzle was designed and installed in a bed reactor to increase the wetting efficiency of solid sorbents. The experimental set up for low temperature SO{sub 2} removal consists of a bed reactor of 3 inches in diameter and 10 feet in length, two high efficiency cyclones for gas/solid separation, sorbent injection and recycling system, water injection system, gas heating system, and gas flow, concentration, temperature and pressuremore » monitoring system. The toroidal shaped nozzle located at the base of the bed has 12 holes placed symmetrically around the ring at an angle of 50{degrees} with the horizontal, and is made of copper tube.« less

  • ;
    The construction of a bench-scale Circulating Fluidized Bed Absorber (CFBA) unit has been completed, and system calibrations have already been performed. In addition, as a novel method injecting water into CFBA, a toroidal-shaped nozzle was designed and installed in a bed reactor to increase the wetting efficiency of solid sorbents. The experimental set up for low temperature SO{sub 2} removal consists of a bed reactor of 3 inches in diameter and 10 feet in length, two high efficiency cyclones for gas/solid separation, sorbent injection and recycling system, water injection system, gas heating system, and gas flow, concentration, temperature and pressuremore » monitoring system. The toroidal shaped nozzle located at the base of the bed has 12 holes placed symmetrically around the ring at an angle of 50{degrees} with the horizontal, and is made of copper tube.« less

  • ;
    Water injection in dry lime injection FGD processes plays a very important role for the SO{sub 2} removal efficiency. The experimental data obtained from circulating fluidized bed absorber (CFBA) operations under water injection through the newly designed toroidal ring nozzle were represented. The results suggest the removal efficiency is a strong function of the water injection rate. In addition. those indicate that the height of water spray is more significant in wetting efficiency during fluidization in CFBA instead of the number of holes. The height should be adjusted depending on the reaction zone in order to improve the wetting efficiencymore » of lime. The effect of gas velocity appeared not significant, resulting from that the wetting efficiency may increase at higher velocities. The loading of sorbents strongly affects on the SO{sub 2} removal as the lime becomes hydrated and attrited, while its effect appears not significant before hydration occurs. As the lime continuously contacts with water droplets, it becomes hydrated and its attrition is significantly taking place. Since the hydration causes the high reactivity and attrition provides the fresh surface of lime, an effective wetting to allow the gradual attrition and hydration can increase the SO{sub 2} removal efficiency and sorbent utilization. Such effective wetting may be obtained by means of spraying with smaller droplets.« less

  • ;
    The nozzle installed in the circulating fluidized bed absorber (CFBA) was slightly modified because of a technical difficulty in making the small holes less than 100 {mu}m. The holes were punctured with a very tiny drill bits in diameter of 275 {mu}m, and the number of holes were adjusted. The 951 TGA (Du Pont Co.) was also modified for the kinetic information on the hydration and sulfation of limes under low temperatures. The modified thermalgravimetric analyzer (TGA) includes a syringe in order to simulate the water sprayings in a CFBA. Water droplets through the needle attached to the syringe aremore » added onto the lime sample in a TGA. Two discrete ranges of Dravo limes were prepared as solid sorbents for sulfation tests. One ranged between 1095 {mu}m (16 mesh) and 2380 {mu}m (8 mesh) in diameter and the other ranged between 595 {mu}m (30 mesh) and 1095 {mu}m (16 mesh). The experimental methods for kinetic studies with TGA and for CFBA operation were established through the pre-operation of CFBA.« less

  • ;
    This project has been proposed to offer a low capital cost flue gas desulfurization (FGD) system which provides high sorbent utilization with operational simplicity. The system would be applicable to either an industrial or utility boiler and could be easily retrofitted in order to meet any changes in SO{sub 2} emission regulations. The results given in this report indicate the effectiveness of the approach. Basically, the circulating fluidized bed absorber (CFBA) consists of a reactor where the solid sorbent is contacted with the high velocity flue gas and the solids are entrained. A dense phase and entrained phase fluidization regionmore » exists (dependent on the particle size and density, and the gas velocity) which promote good gas/solid recycle. A gas/solid separator (cyclone) concentrates the sorbent for subsequent recycle. A pilot scale CFBA unit has been constructed and was evaluated on a number of commercially available sorbents. The reactor consists of 6 inch diameter by 21 foot fluidized bed with two recycle cyclones. Gas flow rate in the experiments was nominally 70 scfm and temperatures ranged from 250{degree}F--900{degree}F. Variables tested included the sorbent loading, recycle rate, sorbent particle size, gas velocity and temperature, and (for calcium oxide sorbent) particle wetting. The results have indicated that over 90% of the inlet sulfur dioxide concentration may be removed at inlet stoichiometric conditions by the use of a sodium bicarbonate sorbent with a solids loading of 6 in-H{sub 2}O. The efficiency of SO{sub 2} removal increases with decreasing particle size for sodium bicarbonate, and decreases with increasing temperature after an optimum of around 400{degree}F inlet gas temperature.« less