题名 | 有机钙盐高温脱硫脱硝反应研究 |
作者 | 高凤霞 |
学位类别 | 硕士 |
答辩日期 | 2000-05 |
授予单位 | 中国科学院研究生院 |
导师 | 曹竹友 |
关键词 | 混合有机钙盐 醋酸钙 脱硫 脱硝 分解 |
其他题名 | A Study of Organic Calcium Salts Characteristics for SO2 and Nox Removal |
学位专业 | 单颗粒反应 |
中文摘要 | 玉米秸秆等生物质废料快速热解产生的包含酸、酮、酚等多种有机物的热解液,与Ca(OH)_2混合可以制备比较廉价的混合有机钙盐,这种混合有机钙盐在钙硫比为1:1的条件下即可同时脱除SO_2和NO_x,是一种非常有前途的高温烟气净化剂。本文以与SO_2含量为2000~3000 ppm的模拟烟气反应1小时后的转化率来表征烟气净化剂的最大脱硫能力,利用微分固定床在730~940℃的温度范围内测定了混合有机钙盐的最大脱硫能力,并与其它净化剂进行了比较。几种净化剂1小时转化率平均值分别为:CaAc_2,91%;Ca(OH)_2, 51%; CaCO_3, 23%;钙加入量不同的混合有机钙盐在84~94%范围中。因此醋酸钙与混合有机钙盐的最大脱硫能力相当,明显高于Ca(OH))2和CaCO_3,而Ca(OH)_2的最大脱硫能力又明显高于CaCo_3。在模拟工业条件的喷雾干燥型反应器中测定了900~1100℃温度范围内上述4种烟气净化剂的快速脱硫脱硝性能。混合有机钙盐的快速脱硫的钙基利用率>CaAc_2>Ca(OH)_2>CaCO_3;混合有机钙盐各个温度下的脱硝利用率平均为6.04%,而醋酸钙为2.39%,混合有机钙盐的脱硝利用率约是CaAc_2的2.5倍;CaCO_3和Ca(OH)_2基本看不出脱硝能力。在实验条件下温度升高,净化剂的脱硫利用率略有增加,醋酸钙和混合有机钙盐在1000℃左右显示出最佳的脱硝能力。氧浓度增加,醋酸钙脱硫利用率下降,脱硝能力随着烟气中氧浓度的降低而增强。有机钙净化剂的硫酸化能提高其脱硝能力。在此基础上提出了一种合理利用混合有机钙盐的改进的炉内喷钙工艺。醋酸钙程序升温分解过程分为脱水、脱丙酮、脱二氧化碳三个阶段。快速分解时,气相产物有丙酮、乙醇、2-丁烯,固相产物的比表面积与孔隙率声速增加,并且比表面积与孔隙之间有良好的线性关系。 |
英文摘要 | Mixed organic calcium salts were obtained with reasonable cost through mixing the pyrolysate from fast pyrolysis of corn straw powder with Ca(OH)_2. It is an excellent de-contaminant for flue gas cleaning since it may remove SO_2 and NO_X simultaneously from flue gas with Ca/S molar ratio of 1:1 at high temperatures. At this paper, the maximum desulfurization capacity of various gas cleaners was represented as their conversion after 1 hour reaction with 2000~3000 ppm SO_2. The maximum desulfurization capability was determined in a differential fixed-bed reactor at the temperature range of 730~940 ℃. Within this temperature range the average 1 hour conversions are, respectively, 91% for CaAc_2, 51% for Ca(OH)_2, 23% for CaCO_3 and 84~93% for mixed organic calcium salts with different calcium contents. The sorbent utilization of mixed organic calcium salts for SO_2 removal is comparable with that of calcium acetate, both are obviously higher than those of Ca(OH)_2 and CaCO_3. Moreover, Ca(OH)_2 is much better than CaCO_3. The characteristics of these four types of gas cleaners for SO_2 removal and NO reduction were examined in a spray drying type entrained flow reactor at the range of 900~1100 ℃ with the gas composition simulating industrial boiler condition and the contacting time about 1 sec. The order of sorbent utilization for fast SO_2 removal is mixed organic calcium salts > CaAc_2 > Ca(OH)_2 > CaCO_3. Utilization of mixed organic calcium salts for fast NO removal is 6.09%, which is approximately 2.5 times higher than CaAc_2 at the same conditions, while both CaCO_3 and Ca(OH)_2 presented no NO reduction ability essentially. Within this temperature range the sorbent utilization for fast SO_2 removal increases with the increase of temperature. With respect to fast NO reduction there exists an optimal temperature for the utilization of mixed organic calcium salts and CaAc_2 which is approximately 1000 ℃ Lower O_2 concentration is beneficial to both SO_2 removal and NO reduction in the O_2 concentration range between 2% to 6%. The experiment result revealed that cleaner sulfation will promote its ability for NO reduction to some extent. At the basis of this study an improved technology of furnace injection of calcium was put forward based on the utilization of mixed organic calcium salts in order to enhance its efficiency and simplify its process. During calcination of calcium acetate, it was found from TGA spectrum that the sample experience three decomposition stages: dehydration, emissions of acetone and CO_2. The pore structures of calcined samples were analyzed and compared with CaCO_3 calcines, showing that the distinct pore structure of calcium acetate calcines allows it to accommodate more sulfated products. It might be one of the main reasons for organic calcium salts to have much better performance than traditional inorganic calcium-based sorbents. |
语种 | 中文 |
公开日期 | 2013-09-26 |
页码 | 86 |
内容类型 | 学位论文 |
源URL | [http://ir.ipe.ac.cn/handle/122111/1939] ![]() |
专题 | 过程工程研究所_研究所(批量导入) |
推荐引用方式 GB/T 7714 | 高凤霞. 有机钙盐高温脱硫脱硝反应研究[D]. 中国科学院研究生院. 2000. |
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