Articles & Issues

Language: english

Conflict of Interest: In relation to this article, we declare that there is no conflict of interest.

This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/bync/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

All issues

열처리조건이 CuO/γ-Al2O3 흡수제의 탈황능에 미치는 영향

Effects of Heat Treatment Condition on Sulfur Removal Capacity of CuO/γ-Al2O3 Sorbent

유경선^† 김상돈¹ 강순국²

Kyung Seun Yoo^† Sang Done Kim¹ Soon Kook Kang²

광운대학교 환경공학과, 서울 139-701 ¹한국과학기술원 화학공학과, 대전 305-701 ²선문대학교 환경공학과, 아산 336-840

Department of Environmental Engineering, Kwangwoon University, Seoul 139-701, Korea ¹Department of Chemical Engineering, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea ²Department of Environmental Engineering, Sunmoon University, Asan 336-840, Korea

HWAHAK KONGHAK, February 2002, 40(1), 70-74(5), NONE

Download PDF

Abstract

열처리온도와 시간이 CuO/γ-Al2O3 흡수제의 탈황능에 미치는 영향을 열중량분석기에서 탈황반응온도(300 ℃, 500 ℃) 변화에 따라 결정하였다. 황산화반응온도 500 ℃(bulk sulfaction)에서는 CuO/γ-Al2O3 흡수제의 탈황능이 열처리온도 800 ℃ 까지 증가하였고 그 이상의 온도에서는 감소하였다. 그러나 탈황반응 온도 300 ℃의 경우는 열처리온도 700 ℃까지 탈황능이 일정하게 유지된 후 약간 감소하였다. 이것은 벌크 황산화 반응은 CuSO4 분해에 의하여 생성되는 SO3 가스에 의하여 진행되지만 표면 황산화 반응은 담지된 CuO의 촉매작용에 의하여 SO2의 표면전이에 의하여 진행되기 때문이다. 800 ℃에서 열처리한 흡수제의 경우 흡수제의 탈황능은 열처리 시간 12시간에서 최대값을 보인후 열처리 시간이 증가할수록 감소하였다. 이러한 결과는 초기단계에서는 담지된 Cu 이온의 표면재분산이 지배적이고 그 이후는 octahedral 자리로부터 tetrahedral 자리이동에 의한 CuAl2O4의 생성이 열처리 시간이 증가할수록 증가하기 때문이다. CuAl2O4에서의 벌크 황산화 반응은 아황산가스와 CuO/γ-Al2O3 흡수제간의 강한결합으로 인하여 일어나지 않으며 CuAl2O4의 존재를 DRS와 XRD를 이용하여 확인하였다.

Effects of heat treatment temperature and time on sulfur removal capacity of CuO/γ-Al2O3 sorbent were determined in a thermogravimetric analyzer with a variation of sulfation temperature (300 ℃, 500 ℃). At sulfation temperature of 500 ℃ (bulk sulfation), sulfur removal capacity of CuO/γ-Al2O3 sorbent increases with increasing heat treatment temperature up to 800 ℃ and then decreases. At sulfation temperature of 300 ℃ (surface sulfation), however, sulfur removal capacity of the sorbent remains constant up to 700 ℃ and then slightly decreases. This is because bulk sulfation advances by SO3 gas decomposed from the CuSO4, whereas surface sulfation goes on by surface transfer of SO2 via catalytic function of CuO. Sulfur removal capacity of sorbent heated at 800 ℃ shows a maximum value at the heat treatment time of 12 hr and then decreases with increasing heat treatment time. This is because redispersion of Cu ions is dominant at initial step and then formation of CuAl2O4 increases with increasing heat treatment time by the movement of impregnated copper ions from octahedral (Oh) to tetrahedral (Td) site. Bulk sulfation does not occur in CuAl2O4 due to the strong bonding of SO2 with CuO/γ-Al2O3 and the existence of CuAl2O4 has been confirmed using diffuse reflectance spectra (DRS) and x-ray diffractometer (XRD).

Keywords

Sorbent Calcination SO2 Desulfurization DRS

References

Kohl AL, Nielsen RB, "Gas Purification," 5th ed., Gulf, Houston, Texas (1997)
Chu KJ, Yoo KS, Kim KT, Mater. Res. Bull., 32(2), 197 (1997)
Lancia A, Musmarra D, Pepe F, Ind. Eng. Chem. Res., 36(1), 197 (1997)
Lee JB, Kim SD, Chem. Eng. J., 69(2), 99 (1998)
Wallin M, Bjerle I, Chem. Eng. Sci., 44, 61 (1989)
Yoo KS, Jeong SM, Kim SD, Park SB, Ind. Eng. Chem. Res., 35(5), 1543 (1996)
Jeong SM, Yoo KS, Kim SD, HWAHAK KONGHAK, 35(1), 116 (1997)
Jeong SM, Kim SD, Ind. Eng. Chem. Res., 36(12), 5425 (1997)
Waqif M, Saur O, Lavelley LC, Perathoner S, Centi G, J. Phys. Chem., 95, 4051 (1991)
Centi G, Riva A, Passarini N, Brambilla G, Hodnett BK, Delmon B, Ruwet M, Chem. Eng. Sci., 45, 2679 (1990)
Centi G, Passarini N, Perathoner S, Riva A, Ind. Eng. Chem. Res., 31, 1947 (1992)
Centi G, Perathoner S, Ind. Eng. Chem. Res., 36(8), 2945 (1997)
Yoo KS, Kim SD, Park SB, Ind. Eng. Chem. Res., 33(7), 1786 (1994)
Nam SW, Gavalas GR, Appl. Catal., 55, 193 (1989)
Friedman RM, Freeman JJ, J. Catal., 55, 10 (1978)
Hierl R, Knozinger H, Urbach H, J. Catal., 69, 475 (1981)
Koballa TE, Dudukovic MP, AIChE Symp. Ser., 73, 199 (1978)
Kocaefe D, Karman D, Steward FR, AIChE J., 33, 1835 (1987)