INFLUENCE OF O2 AND NO2 ON ADSORPTION PRODUCTS OF SO2 BY Ca(OH)2 AT LOW TEMPERATURE
-
摘要: 在100℃的无水蒸气条件下研究以Ca(OH)2为吸收剂同时脱硫脱硝过程中SO2的固定和氧化过程,以及O2和NO2的作用。分别用原位漫反射傅里叶红外光谱和固定床反应器,研究过程中Ca(OH)2表面和气相的成分变化。结果表明:SO2吸附在Ca(OH)2表面形成的CaSO3不易被O2氧化,但可以被NO2氧化。同时脱除过程中,NO2对CaSO3的氧化具有选择性:930~936 cm-1位置的红外吸收峰在反应过程中先升高后降低,980~995 cm-1位置的红外吸收峰只升高不降低。无O2条件下,参与反应的NO2以接近1∶1的比例转化为NO,而有O2条件下Ca(OH)2同时脱除NO2和SO2时,Ca(NO3)2的含量明显增加,且反应前期CaSO4的生成速率加快。
-
关键词:
- 同时脱硫脱硝 /
- CaSO3氧化 /
- 气固反应 /
- 原位漫反射红外光谱分析 /
- 固定床实验
Abstract: In order to analyze the fixation and oxidation reaction of SO2 in simultaneous removal of SO2 and NOx by Ca(OH)2, and the influence of O2 and NO2 on this progress, DRIFTS(diffuse reflectance infrared Fourier transform spectrometry) and fixed bed reactor were used respectively for composition changes of solid and gas phase at 100 ℃ and 0% RH. The results showed that firstly SO2 was rapidly adsorbed on Ca(OH)2 to form CaSO3, which could hardly be oxidized by O2, but could be oxidized to CaSO4 by NO2. CaSO3 showed selectivity during simultaneous removal process, of which the infrared absorption peak at the position of 930~936 cm-1 first increased and then decreased, while the peak at 980~995 cm-1 monotonically increased.When SO2 and O2 coexisted in the gas, it could react with Ca(OH)2 to form CaSO4. When NO2 and SO2 were simultaneously removed by Ca(OH)2 in the absence of O2, the ratio of produced NO/consumed NO2 was around 1:1, but in the presence of O2, the content of Ca(NO3)2 increased significantly, and the formation rate of CaSO4 was accelarated in the early stage of reation. -
中华人民共和国国家统计局. 年度数据:废气中主要污染物排放[R]. 2017. http://data.stats.gov.cn. 赵雪,程茜,侯俊先.脱硫脱硝行业2017年发展综述[J].中国环保产业,2018(7):10-24. ZHENG C H, XU C R, GAO X, et al. Simultaneous absorption of NOx and SO2 in oxidant-enhanced limestone slurry[J]. Environmental Progress & Sustainable Energy, 2014, 33(4):1171-1179. 朱晓华,李鹏飞,程正霖, 等.低温烟气循环流化床同时脱硫脱硝技术在津西钢铁厂的应用[J].环境工程,2018,36(12):21-25. 陈国庆,高继慧,黄启龙, 等. 钙基脱硫工艺协同脱硝技术研究进展[J].化工进展,2015,34(10):3755-3761. TSUCHIAI H, ISHIZUKA T, NAKAMURA H, et al. Removal of sulfur dioxide from flue gas by the absorbent prepared from coal ash:effects of nitrogen oxide and water vapor[J]. Industrial & Engineering Chemistry Research, 1996, 35(3):851-855. 张虎. 常温钙基吸收剂同时脱除NOx/SO2的实验研究[D]. 北京:清华大学, 2006. SAKAI M, CAILI SU A, SASAOKA E. Simultaneous removal of SOx and NOx using slaked lime at low temperature[J]. Industrial & Engineering Chemistry Research, 2002, 41(20):5029-5033. SONG Q, KOSHI M, SADAKATA. Investigation on promising additives for simultaneous oxidation of NO and SO2 in flue gas by numerical simulation[J].Chinese Journal of Chemical Engineering,2003,11(5):45-49. LITTLEJHON D, WANG Y Z, CHANG S G. Oxidation of aqueous sulfite ion by nitrogen-dioxide[J]. Environmental Science & Technology, 1993, 27(10):2162-2167. BAUSACH M, PERA-TITUS M, FITÉ C, et al. Enhancement of gas desulfurization with hydrated lime at low temperature by the presence of NO2[J]. Industrial & Engineering Chemistry Research, 2005, 44(24):9040-9049. 张晓闻. 常温钙基同时脱硫脱硝机理[D].北京:清华大学, 2008. 李鹏飞. 反应条件对钙基吸收剂脱除NOx/SO2效果影响的实验研究[D].北京:清华大学, 2009. CHEN G Q, GAO J H, GAO J M, et al. Simultaneous removal of SO2 and NOx by calcium hydroxide at low temperature:effect of SO2 absorption on NO2 removal[J]. Industrial & Engineering Chemistry Research, 2010, 49(23). BALTRUSAITIS J, SCHUTTLEFIELD J, JENSEN J H, et al. FTIR spectroscopy combined with quantum chemical calculations to investigate adsorbed nitrate on aluminium oxide surfaces in the presence and absence of co-adsorbed water[J]. Physical Chemistry Chemical Physics, 2007, 9(36):4970-4980. LOW M J D, GOODSEI A J, TAKEZAW N. Reactions of gaseous pollutants with solids. i. infrared study of the sorption of SO2 on CaO[J]. Environmental Science & Technology, 1971, 5(12):1191-1195. WILDE J D, MARIN G B. Investigation of simultaneous adsorption of SO2 and NOx on Na-alumina with transient techniques[J]. Catalysis Today, 2000, 62(4):319-328. USHER C, AL-HOSNEY H, CARLOS-CUELLAR S, et al. A laboratory study of the heterogeneous uptake and oxidation of sulfur dioxide on mineral dust particles[J]. Journal of Geophysical Research:Atmospheres, 2002, 107(D23):161-169. LEE K T, BHATIA S, MOHAMED A R. Removal of sulfur dioxide using absorbent synthesized from coal fly ash:Role of oxygen and nitrogen oxide in the desulfurization reaction[J]. Chemical Engineering Science, 2005, 60(12):3419-3423. ELFVING P, PANAS I, LINDQVIST O. Model study of the first steps in the deterioration of calcareous stone. I. Initial surface sulphite formation on calcite[J]. Applied Surface Science, 1994, 74:91-98. 李天津,禚玉群,陈昌和, 等. 含水条件下多组分污染气体的FTIR同时在线测量[J]. 清华大学学报(自然科学版), 2008,48:(11):1971-1975. NAKAMOTO K. Infrared and Raman Spectra of Inorganic and Coordination Compounds[M]. Part A and Part B, Two Volume Set, 6 Edition. Wiley, 2009. KRAMMER G, BRUNNER C, KHINAST J, et al. Reaction of Ca(OH)2 with SO2 at Low Temperature[J]. Industrial & Engineering Chemistry Research, 1997, 36(5):1410-1418. NELLI C H, ROCHELLE G T. Simultaneous sulfur dioxide and nitrogen dioxide removal bycalcium hydroxide and calcium silicate solids[J]. Journal of the Air & Waste Management Association, 1998,48(9):819-828. GLEASON J F, HOWARD C J. ChemInform abstract:temperature dependence of the gas-phase reaction HOSO2+O2→HO2+SO3[J]. ChemInform, 1988, 19(37):3414-3417. CHEN G Q, GAO J H, WANG S, et al. Enhancement effects of gas components on NO removal by calcium hydroxide[J]. Industrial & Engineering Chemistry Research, 2010, 49(3):1450-1456. 李平. SO2对负载型催化剂上NO氧化过程的影响[D]. 上海:华东理工大学, 2003. WILDE J D, MARIN G B. Investigation of simultaneous adsorption of SO2 and NOx on Na-γ-alumina with transient techniques[J]. Catalysis Today, 2000, 62(4):319-328. GOODSEL A J, LOW M J D, NOBUTSUNE T. Reactions of Gaseous Pollutants with solids. Ⅱ. Sorption of SO2 on MgO[J]. Environmental Science & Technology,1972,6(3):268-273.
点击查看大图
计量
- 文章访问数: 127
- HTML全文浏览量: 8
- PDF下载量: 9
- 被引次数: 0