New & Renewable Energy (신재생에너지)

Korean Society for New and Renewable Energy (한국신·재생에너지학회)
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A Study on Prevention of Fouling Formation by Reduction Reaction of CaSO4 in a Biomass Circulating Fluidized Bed Combustion

바이오매스 순환유동층 연소에서 CaSO4 환원반응에 의한 파울링 발생 방지 연구

  • Seong-Ju Kim (Climate Change Research Division,Korea Institute of Energy Research (KIER)) ;
  • Sung-Jin Park (Climate Change Research Division, Korea Institute of Energy Research (KIER)) ;
  • Sung-Ho Jo (Climate Change Research Division, Korea Institute of Energy Research (KIER)) ;
  • Se-Hwa Hong (Biomass Maintenance Team #2, GS Electric Power Solution (GS EPS)) ;
  • Yong-Il Mun (Biomass Maintenance Team #2, GS Electric Power Solution (GSEPS)) ;
  • Tae-Young Mun (Climate Change Research Division, Korea Institute of Energy Research (KIER))
  • Received : 2023.01.02
  • Accepted : 2023.02.09
  • Published : 2023.03.25
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Abstract

A large amount of carbon monoxide (CO) is generated in circulating fluidized bed combustion, the process whereby a hot cyclone separates unburned fuel. However, calcium sulfate (CaSO4), when combined with a high CO content, can cause fouling on the surface of the steam tube installed inside the integrated recycle heat exchangers (INTREX). In this study, CaSO4 decomposition was investigated using 0.2-3.2 vol.% CO and 1-3 vol.% oxygen (O2) at 850℃ for 20 min in a lab-scale fluidized bed reactor. The results show that CaSO4 decomposes into CaS and CaO when CO gas is supplied, and SO2 emissions increase from 135 ppm to 1021 ppm with increasing CO concentration. However, the O2 supply delayed SO2 emissions because the reaction between CO and O2 is faster than that of CaSO4; nevertheless, when supplied with CaCO3, the intermediate product, SO2 was significantly released, regardless of the CO and O2 supply. In addition, agglomerated solids and yellow sulfur power were observed after solid recovery, and the reactor distributor was corroded. Consequently, a sufficient O2 supply is important and can prevent fouling formation on the INTREX surface by suppressing CaSO4 degradation.

Keywords

Acknowledgement

이 연구는 2019년도 산업통상자원부 및 산업기술평가관리원(KEIT) 연구비 지원에 의한 연구임('20005788').

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