CaO-Fe_2O_3/γ-Al_2O_3再生SO_2脱硫剂的制备及脱硫再生研究
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摘要
大量从燃煤锅炉里排放出来的SO_2不仅对环境造成严重危害，还是硫资源的一种很大浪费，每年排入水气的SO_2近2370万吨。再生脱硫技术是有效控制大气污染，合理回收资源的重要手段。
作者制备了新型复合CaO-Fe_2O_3／γ-Al_2O_3负载型再生烟气脱硫剂。在600℃下对模拟烟气进行了脱硫研究，硫容达7.7％(wt)，脱硫反应后可用CH_4再生直接回收单质S。所得脱硫剂有较好的脱硫再生性能，经4次脱硫再生循环，平均再生率达81.3％。
脱硫剂中引入Fe可以通过催化SO_2氧化反应而改变了CaO／γ-Al_2O_3脱硫剂脱除SO_2的反应历程。Fe与CaO之间存在一定的交互作用，大大提高了脱硫剂对SO_2的脱除性能。脱硫剂中的活性物质氧化钙和氧化铁在脱硫过程中同烟道气中的SO_2和氧气反应转变成硫酸钙和硫酸铁，还原再生时又转变成原有结构的氧化钙和氧化铁，获得再生。
对脱硫剂制备工艺进行了研究，浸渍溶液Ca(NO_3)_2的浓度与所得脱硫剂的CaO负载量呈线性关系，在一定的浓度范围内，CaO的负载量可以根据浸渍溶液浓度进行预测估算。Ca—Fe双组分脱硫剂中Ca、Fe含量的最适宜比例为3：1。Ca、Fe分步浸渍时SO_2去除率、脱硫速率以及脱硫硫容等指标均优于同时浸渍。最佳脱硫温度为600℃，脱硫后脱硫剂最大S／(Ca+Fe)原子比为0.7。
A huge emission of SO2 from the chimneys of coal combustion boilers is not only a serious environmental problem, but also a great waste of sulfur resource. About 23,7 million tons of SO2 is emitted into atmosphere every year. Regenerative desulfurization process is an effective measure to control air pollution and recover sulfur resource.
A novel complex alumina supported calcium oxide and ferric oxide adsorbent was prepared by step wet impregnation method. The desulfurization and regeneration behaviors of this adsorbent were tested at 600C. The results indicate that the sulfur capacity of the adsorbent reaches 7.7 wt%. The adsorbent can be regenerated with CH4, and sulfur is the only regeneration product. The activity maintains as high as 81.3% of the initial activity after four desulfurization-regeneration cycles.
The mechanism of desulfurization reaction can be changed by introducing ferric oxide. The ferric oxide is a catalyst of SO2 oxidization. A strong interaction exits between calcium oxide and ferric oxide. The desulfurization behavior is greatly improved by introducing ion into adsorbent. The active components, calcium oxide and ferric oxide convert to calcium sulphate and ferric sulphate during desulfurization, then the sulfates are reduced to obtain calcium oxide and ferric oxide in regeneration.
The preparation of the adsorbent was researched. The calcium oxide loading of adsorbent is proportional to the concentration of calcium nitrate in impregnation solution. So the calcium oxide loading can be estimated according to the concentration of impregnation solution within a given concentration range. The optimal ratio of active components Ca to Fe in complex adsorbent is 3:1. The desulfurization rate and sulfur capacity of the adsorbents prepared by step impregnation method are high than those of the adsorbents prepared by mixed impregnation. The optimal temperature of desulfurization is 600 C. At this temperature, the maximal ratio of S/(Ca+Fe) is 0.7 after desulfurization.
作者制备了新型复合CaO-Fe_2O_3／γ-Al_2O_3负载型再生烟气脱硫剂。在600℃下对模拟烟气进行了脱硫研究，硫容达7.7％(wt)，脱硫反应后可用CH_4再生直接回收单质S。所得脱硫剂有较好的脱硫再生性能，经4次脱硫再生循环，平均再生率达81.3％。
脱硫剂中引入Fe可以通过催化SO_2氧化反应而改变了CaO／γ-Al_2O_3脱硫剂脱除SO_2的反应历程。Fe与CaO之间存在一定的交互作用，大大提高了脱硫剂对SO_2的脱除性能。脱硫剂中的活性物质氧化钙和氧化铁在脱硫过程中同烟道气中的SO_2和氧气反应转变成硫酸钙和硫酸铁，还原再生时又转变成原有结构的氧化钙和氧化铁，获得再生。
对脱硫剂制备工艺进行了研究，浸渍溶液Ca(NO_3)_2的浓度与所得脱硫剂的CaO负载量呈线性关系，在一定的浓度范围内，CaO的负载量可以根据浸渍溶液浓度进行预测估算。Ca—Fe双组分脱硫剂中Ca、Fe含量的最适宜比例为3：1。Ca、Fe分步浸渍时SO_2去除率、脱硫速率以及脱硫硫容等指标均优于同时浸渍。最佳脱硫温度为600℃，脱硫后脱硫剂最大S／(Ca+Fe)原子比为0.7。
A huge emission of SO2 from the chimneys of coal combustion boilers is not only a serious environmental problem, but also a great waste of sulfur resource. About 23,7 million tons of SO2 is emitted into atmosphere every year. Regenerative desulfurization process is an effective measure to control air pollution and recover sulfur resource.
A novel complex alumina supported calcium oxide and ferric oxide adsorbent was prepared by step wet impregnation method. The desulfurization and regeneration behaviors of this adsorbent were tested at 600C. The results indicate that the sulfur capacity of the adsorbent reaches 7.7 wt%. The adsorbent can be regenerated with CH4, and sulfur is the only regeneration product. The activity maintains as high as 81.3% of the initial activity after four desulfurization-regeneration cycles.
The mechanism of desulfurization reaction can be changed by introducing ferric oxide. The ferric oxide is a catalyst of SO2 oxidization. A strong interaction exits between calcium oxide and ferric oxide. The desulfurization behavior is greatly improved by introducing ion into adsorbent. The active components, calcium oxide and ferric oxide convert to calcium sulphate and ferric sulphate during desulfurization, then the sulfates are reduced to obtain calcium oxide and ferric oxide in regeneration.
The preparation of the adsorbent was researched. The calcium oxide loading of adsorbent is proportional to the concentration of calcium nitrate in impregnation solution. So the calcium oxide loading can be estimated according to the concentration of impregnation solution within a given concentration range. The optimal ratio of active components Ca to Fe in complex adsorbent is 3:1. The desulfurization rate and sulfur capacity of the adsorbents prepared by step impregnation method are high than those of the adsorbents prepared by mixed impregnation. The optimal temperature of desulfurization is 600 C. At this temperature, the maximal ratio of S/(Ca+Fe) is 0.7 after desulfurization.
引文
1 Wieckowska J,Catal. Today, 1995,24:405～465
2 陈鹏，中国高硫煤及其排放SO_2污染控制，煤炭转化，1998,21(3)：1-6
3 王文兴，中国酸雨现状及发展趋势，科学通报．1997，42(2)：169—173 1
4 雷震东，吴创之等，我国燃煤二氧化硫污染的控制技术及其应用，煤炭转化，1998，21(4)：7—11
5 Smock. R. Power Engineering, 1990, 94 (7): 34-36
6 余嫒嫒等，燃煤锅炉烟气脱硫技术及其应用现状与对策，环境与开发，2000，15(2)：21-23
7 钱海燕等，燃煤电厂烟气脱硫技术发展现状，环境导报，1999，6：11-14
8 郝吉明，燃媒二氧化硫污染控制技术现状及综合评价(一)，环境保护，1998，4：4～6
9 冯玲等，烟气脱硫技术的发展及应用现状，环境工程，1997，15(2)：19-24
10 前泽章彦，电子线照射排力处理技术
11 Paik S C, Chung JS. Selective Catalytic Reduction of Sulfur Dioxide with Hydrogen to Elemental Sulfur over Co-Mo/Al_2O_3. Applied Catalysis B: Environmental, 1995, 5:233～243
12 李忠于，国外烟气脱硫技术，硫酸工业，1996，4：1～12
13 Tsujik, Shiraishil. Fuel, 1997,76(6):549-560,
14 邹长武，尹华强等，粘胶基活性炭纤维的脱硫性能，环境工程，2001，19(1)
15 Kwong V, Meissner R E. Chem. Eng.,1995,2:74～83
16 Armor J N ,Appl. Catal. B, 1992,1:221～256
17 斯克莱A V．废气脱硫，上海市轻工设计院技术情报组，上海同济大学供热通风教研室译，中国建筑工业出版社，1977。
18 Uysal B Z. Sorption of SO_2 on metal oxides in a fluidized bed. Ind. Eng. Chem. Res.,1988, 27:434～439
19 Waqif M, et al. Nature and Mechanism of Formation of Sulfate Species on Copper/Alumina Sorbent-Catalysts for SO_2 Removal, J. Phys. Chem., 1991, 95:4051～4058
20 Kartheuser B, Hodnett B K., Ind. Chem. Res., 1991, 30:2105～2113
21 Centi G..,Combined DeSQx/DeNOx Reactions on a copper on Alumina Sorbent-Catalyst,
Ind.Eng. Res., 1992, 31(8): 1947～1955
22 GarBowski E., Primet M. J., Chem. Soc., Chem. Commun., 1991
23 陈银飞，葛忠华等，不同制备方法对MgFe氧化物催化吸附SO_2性能的影响，化工学报，2001，52(5)：429～433
24 陈银飞，卓广澜等，MgAIFe复合氧化物高温下脱除低浓度SO_2的性能，高校化学工程学报，2000，14(4)：346～351
25 阮桂色，负载型金属氧化物烟气脱硫剂的研究，矿冶，2000，9(1)：99～102
26 Pollack S S, Chisholm W P, Obermyer R T et Al. Properties of Copper/Alumina Sorbents Used for the Removal of Sulfur Dioxide. Ind Eng Chem Res, 1988, 27(12) :2276～2282
27 Sidney S. Pollack, William P. Chisholm, Properties of Copper/Alumina Sorbents Used for the Removal of Sulfur Dioxide, Ind. Eng. Chem. Res. 1988, 27(12): 2276～2282
28 沈德树、甘海明，以CuO为主要活性组分同时脱硫脱硝催化剂的研究，湖南大学学报，1994，21(1)：103～108
29 刘守军、刘振宇等，高活性活性炭载金属脱硫剂的制备与筛选，煤炭转化，2000，23(2)：53～58
30 Friedman R. M., Characterization of Cu/Al_2O_3 Catalysts, J. Catal. 1978,55,10～28
31 Strohmier B. R., Leyden D. E., Surface Spectroscopic Characterization of Cu/Al_2O_3 Catalysts, J. Catal. 1985, 94, 541～530
32 梁斌，汪涛，吴潘，Hn／γ—Al_2O_3高温脱硫剂的制备，四川大学学报(工程科学版)，2002，34(1)：11～15
33 B.Liang, R.Korbee, Preparation of the Mn/Al_2O_3 Acceptor for high temperature regeneration H_2S removal, Canadian Journal of Chemical Engineering, 1999,77(6):483～488
34 张金昌，吴迪镛，Hn—Fe／γ—Al2O_3高温脱除H_2S是实验研究Ⅱ，燃料化学学报，1999，27(6)：505～509
35 李玉敏，工业催化，天津大学出版社，1996。
36 叶大伦编，适用无机物热力学数据物手册，冶金工业出版社，1981，北京
37 Philip R W., Eviron. Sci. Tachnol, 1977,11:448
38 E.H.P Wolff, Regenerative sulfur capture in fiuidized bed combustion of coal:affixed bed sorption study. Dlft University Press, 1991
39 Koballa, T.E.;Dudukovic, M.P.AICHE Symp. Set 1970,73(165): 199～
40 Best R.J., Yate J.G,Ind. Eng. Chem. Process Des .Dev. 1977,16(3):347
41 Cho M. H., Lee,V.K., SO_2 removal by CuO on γ-Al_2O_3, J.Chem. Eng. Jpn., 1983,16(2):127
42 Bekir Zuhtu Uysal et al, Ind. eng. Chem. Res., 1988,27(3):434～439
43 李彦旭，李春虎，铁钙氧化物高温煤气脱硫剂的制备，燃料化学学报，1999，27(6)；529～534
44 刘守军，刘振宇等，新型低温CuO／AC脱硫剂制备及表征载铜量对脱硫活性的影响，燃料化学学报，1999，27(增刊)：186～194
45 Wakker J. P, Development of a high temperature steam regenerative H_2S removal process based On Alumina supported MnO and FeO, Ph.D. Thesis, Delft University Of Technology,1985.
46 Scholten J J, Katalyse en Katalysatoren[R], The Netherlands: Delft University Of Technology, 1989.
2 陈鹏，中国高硫煤及其排放SO_2污染控制，煤炭转化，1998,21(3)：1-6
3 王文兴，中国酸雨现状及发展趋势，科学通报．1997，42(2)：169—173 1
4 雷震东，吴创之等，我国燃煤二氧化硫污染的控制技术及其应用，煤炭转化，1998，21(4)：7—11
5 Smock. R. Power Engineering, 1990, 94 (7): 34-36
6 余嫒嫒等，燃煤锅炉烟气脱硫技术及其应用现状与对策，环境与开发，2000，15(2)：21-23
7 钱海燕等，燃煤电厂烟气脱硫技术发展现状，环境导报，1999，6：11-14
8 郝吉明，燃媒二氧化硫污染控制技术现状及综合评价(一)，环境保护，1998，4：4～6
9 冯玲等，烟气脱硫技术的发展及应用现状，环境工程，1997，15(2)：19-24
10 前泽章彦，电子线照射排力处理技术
11 Paik S C, Chung JS. Selective Catalytic Reduction of Sulfur Dioxide with Hydrogen to Elemental Sulfur over Co-Mo/Al_2O_3. Applied Catalysis B: Environmental, 1995, 5:233～243
12 李忠于，国外烟气脱硫技术，硫酸工业，1996，4：1～12
13 Tsujik, Shiraishil. Fuel, 1997,76(6):549-560,
14 邹长武，尹华强等，粘胶基活性炭纤维的脱硫性能，环境工程，2001，19(1)
15 Kwong V, Meissner R E. Chem. Eng.,1995,2:74～83
16 Armor J N ,Appl. Catal. B, 1992,1:221～256
17 斯克莱A V．废气脱硫，上海市轻工设计院技术情报组，上海同济大学供热通风教研室译，中国建筑工业出版社，1977。
18 Uysal B Z. Sorption of SO_2 on metal oxides in a fluidized bed. Ind. Eng. Chem. Res.,1988, 27:434～439
19 Waqif M, et al. Nature and Mechanism of Formation of Sulfate Species on Copper/Alumina Sorbent-Catalysts for SO_2 Removal, J. Phys. Chem., 1991, 95:4051～4058
20 Kartheuser B, Hodnett B K., Ind. Chem. Res., 1991, 30:2105～2113
21 Centi G..,Combined DeSQx/DeNOx Reactions on a copper on Alumina Sorbent-Catalyst,
Ind.Eng. Res., 1992, 31(8): 1947～1955
22 GarBowski E., Primet M. J., Chem. Soc., Chem. Commun., 1991
23 陈银飞，葛忠华等，不同制备方法对MgFe氧化物催化吸附SO_2性能的影响，化工学报，2001，52(5)：429～433
24 陈银飞，卓广澜等，MgAIFe复合氧化物高温下脱除低浓度SO_2的性能，高校化学工程学报，2000，14(4)：346～351
25 阮桂色，负载型金属氧化物烟气脱硫剂的研究，矿冶，2000，9(1)：99～102
26 Pollack S S, Chisholm W P, Obermyer R T et Al. Properties of Copper/Alumina Sorbents Used for the Removal of Sulfur Dioxide. Ind Eng Chem Res, 1988, 27(12) :2276～2282
27 Sidney S. Pollack, William P. Chisholm, Properties of Copper/Alumina Sorbents Used for the Removal of Sulfur Dioxide, Ind. Eng. Chem. Res. 1988, 27(12): 2276～2282
28 沈德树、甘海明，以CuO为主要活性组分同时脱硫脱硝催化剂的研究，湖南大学学报，1994，21(1)：103～108
29 刘守军、刘振宇等，高活性活性炭载金属脱硫剂的制备与筛选，煤炭转化，2000，23(2)：53～58
30 Friedman R. M., Characterization of Cu/Al_2O_3 Catalysts, J. Catal. 1978,55,10～28
31 Strohmier B. R., Leyden D. E., Surface Spectroscopic Characterization of Cu/Al_2O_3 Catalysts, J. Catal. 1985, 94, 541～530
32 梁斌，汪涛，吴潘，Hn／γ—Al_2O_3高温脱硫剂的制备，四川大学学报(工程科学版)，2002，34(1)：11～15
33 B.Liang, R.Korbee, Preparation of the Mn/Al_2O_3 Acceptor for high temperature regeneration H_2S removal, Canadian Journal of Chemical Engineering, 1999,77(6):483～488
34 张金昌，吴迪镛，Hn—Fe／γ—Al2O_3高温脱除H_2S是实验研究Ⅱ，燃料化学学报，1999，27(6)：505～509
35 李玉敏，工业催化，天津大学出版社，1996。
36 叶大伦编，适用无机物热力学数据物手册，冶金工业出版社，1981，北京
37 Philip R W., Eviron. Sci. Tachnol, 1977,11:448
38 E.H.P Wolff, Regenerative sulfur capture in fiuidized bed combustion of coal:affixed bed sorption study. Dlft University Press, 1991
39 Koballa, T.E.;Dudukovic, M.P.AICHE Symp. Set 1970,73(165): 199～
40 Best R.J., Yate J.G,Ind. Eng. Chem. Process Des .Dev. 1977,16(3):347
41 Cho M. H., Lee,V.K., SO_2 removal by CuO on γ-Al_2O_3, J.Chem. Eng. Jpn., 1983,16(2):127
42 Bekir Zuhtu Uysal et al, Ind. eng. Chem. Res., 1988,27(3):434～439
43 李彦旭，李春虎，铁钙氧化物高温煤气脱硫剂的制备，燃料化学学报，1999，27(6)；529～534
44 刘守军，刘振宇等，新型低温CuO／AC脱硫剂制备及表征载铜量对脱硫活性的影响，燃料化学学报，1999，27(增刊)：186～194
45 Wakker J. P, Development of a high temperature steam regenerative H_2S removal process based On Alumina supported MnO and FeO, Ph.D. Thesis, Delft University Of Technology,1985.
46 Scholten J J, Katalyse en Katalysatoren[R], The Netherlands: Delft University Of Technology, 1989.