钙基碱对粉煤灰中氨脱附的影响  

Effect of calcium alkali on ammonia desorption in fly ash

作　　者：唐潇 徐仁博 马云龙 张发捷 赵宏 王乐乐[3] 于洁[1] 孙路石[1] TANG Xiao;XU Renbo;MA Yunlong;ZHANG Fajie;ZHAO Hong;WANG Lele;YU Jie;SUN Lushi(State Key Laboratory of Coal Combustion,Huazhong University of Science and Technology,Wuhan 430074,China;Huaneng Dalian Power Plant,Dalian 116033,China;Suzhou Branch of Xi′an Thermal Power Research Institute Co.,Ltd.,Suzhou 215153,China)

机构地区：[1]华中科技大学煤燃烧国家重点实验室,湖北武汉430074 [2]华能大连电厂,辽宁大连116033 [3]西安热工研究院有限公司苏州分公司,江苏苏州215153

出　　处：《洁净煤技术》2022年第2期152-159,共8页Clean Coal Technology

基　　金：华能集团众创资助项目(SK-461021010)。

摘　　要：为解决我国目前广泛存在的SCR后飞灰残存硫酸氢铵(ABS)的技术难题,选取碱性、酸性2种粉煤灰为试验原料,对2种飞灰加水脱ABS,研究飞灰中内在碱/碱土金属对ABS的脱除影响;在此基础上,分别向飞灰中加入一定量钙基碱与水,研究钙基碱对粉煤灰中氨脱附的影响。结果表明,对于碱性灰,不加入额外的碱,只加入少量水并搅拌就可促进灰中部分氨释放。而向酸性灰中加入等量的水并搅拌,释放出的氨很少。向灰中加入1%Ca(OH)_(2)和2%H_(2)O,搅拌5 min,灰中95%以上ABS可被有效脱除。在相同条件下,CaO对灰中氨脱除效果略差于Ca(OH)_(2)。相较加热法,加碱法在常温下进行,且加入少量水,灰易干燥。基于加碱法原理的灰中氨脱除装置对含氨灰有很好的脱氨效果。对于氨平均质量分数近300×10^(-6)的粉煤灰,向灰中加入1%Ca(OH)_(2)、2%H_(2)O,不经加热处理,只使用搅拌混合器搅拌便可去除灰中75%以上的氨,加热处理后,灰中氨进一步被脱除,氨脱除率可达90%以上,可保证处理后粉煤灰中氨质量分数低于100 mg/kg,对后续利用无不利影响。In order to solve the technical problem of residual ammonium bisulfate(ABS) in SCR fly ash in China, alkaline and acidic fly ash were selected as the test materials, and the two kinds of fly ash were added with water to remove ABS,and the effect of internal alkali/alkaline earth metals in fly ash on the removal of ABS was studied;on this basis, a certain amount of calcium-based alkali and water were added to explore the effect of this method on ammonia desorption in fly ash. The results show that adding a small amount of water to the ash and stirring at room temperature can promote the release of part of the ammonia in the alkaline ash, while the acid ash releases very little ammonia. Adding 1% Ca(OH)_(2),2% H_(2)O to acid and alkaline ash, more than 95% of the ammonia in the ash is removed after stirring 5 minutes. Under the same conditions, the effect of CaO on ammonia removal in fly ash is slightly worse than Ca(OH)_(2). Compared with the heating method, the alkali addition method is carried out at room temperature, and little water is added, so the ash is easy to dry. The test device for ammonia removal in ash based on the alkali addition method has a good deamination effect. For fly ash containing 300×10^(-6)ABS,the addition of 1% Ca(OH)_(2)and 2% H_(2)O can remove 75% ABS from fly ash by mixing with a mixer without heating treatment. After heating treatment, the ammonia in the ash is further removed, and the ammonia removal rate can reach more than 90%,which can ensure that that the content of ammonia in ash is less than 100 mg/kg after treatment, and will not have an adverse impact on subsequent utilization.

关 键 词：粉煤灰 硫酸氢铵(ABS) 钙基碱 氨脱附 加热法 加碱法 

分 类 号：X773[环境科学与工程—环境工程]