Journal of the Korean Industrial and Engineering Chemistry, Vol.13, No.5, 468-475, August, 2002
Dibasic Acid에 의한 석회석 슬러리의 탈황반응성과 석고 결정화에 관한 연구
Study of Desulfurization of Limestone and Crystal Habit of Gypsum by adding Dibasic Acid as Buffer Additives
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초록
화력발전소에서 화석 연료 연소 후 발생하는 SO2를 제거하는 방법으로 널리 사용되고 있는 배연탈황설비는 석회석을 알칼리 흡수제로 사용하여 탈황 반응 후 부산물로 석고를 얻는 방법이다. 이와 관련된 연구는 오랫동안 지속되어왔으며 현재는 SO2 제거효율 향상과 고순도 석고를 얻기 위한 첨가제 연구가 활발히 진행되고 있다. 본 연구는 SO2 제거 효율향상을 위하여 섞어주는 여러 가지 첨가제 중 아디프산 제조 공정에서 발생하는 부산물 (Dibasic acid, DBA)을 완충 첨가제로 선정하였고, 아디프산, 글루타르산, 말론산, 숙신산과 같은 다른 유기산과 비교실험을 수행하였다. 본 실험을 통하여, 첨가해준 DBA는 반응 생성물인 석고 결정에 영향을 주지 않으나 석회석의 용해와 SO2흡수 계면사이의 완충 역할을 함으로써 석회석의 용해도와 SO2제거 효율을 증가시키는 효과를 가지고 있음을 알 수 있었다.
The flue gas desulfurization (FGD) systems are commonly utilized to remove sulfur dioxide from stack gases of coal-fired or diesel-fired plants. These FGD plants use a lot of limestones as alkali absorbent and produce a lot of gypsum as a byproduct. Nowadays, research and development of buffering additives have been lively studied to increase efficiency of SO2 removal and to produce high-quality gypsum as a byproduct. In this work, DBA which is produced as byproduct from adipic acid process of Rhodia company was selected as a test additive. The SO2 removal efficiency of the samples, glutaric acid, malonic acid, succinic acid and DBA, was compared with those of adipic acid such as buffer additives. The addition of organic acid increased CaCO3 dissolution rate and SO2 removal efficiency. It was found that DBA has a buffering effect in the phase boundaries between solubility of CaCO3 and SO2 absorption. There was no effect of crystal habit for DBA and organic acid, but the addition of DBA may increase a conversion rate of sulfite into sulfate and the SO2 removal efficiency. DBA was identified to be a good buffer additive in this work.
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