【作者】 郑显玉；

【导师】 陈昌和；

【作者基本信息】 清华大学 ， 热能工程， 2002， 硕士

【摘要】 为了减少酸雨、温室效应及臭氧层破坏等造成的危害，有必要对化石燃料燃烧以后产生的气态污染物排放进行控制，实现可持续发展。氨(NH3)在脱除烟气中的气态污染物方面已经显示出了其有效性。本论文研究内容分成两大部分：一. 氨法脱除二氧化硫的试验研究；二. 氨法脱除二氧化碳的试验研究。作者设计完成了利用氨法脱除电厂烟气中多种气态污染物的试验装置，在该装置上可以分别实现对SO2以及CO2连续脱除的试验研究。在脱硫试验中，我们采用气态氨加水蒸气对人工烟气中的SO2进行脱除，分析影响脱除率的因素，特别是主导制约因素，并对脱硫反应做了初步的反应动力学分析。试验结果显示：在所有的操作温度下，对SO2的脱除率都大于60%；温度越高，达到稳定的脱硫率所需的综合反应时间越长；当温度超过80℃时，氨对SO2仍有很高的脱除率；在40℃ ~85℃温度窗口内，脱硫反应所需的反应时间基本相同。并根据试验结果建议，在实际氨法脱硫工程中，脱硫反应宜控制在60℃或以下的温度下进行。第二部分中，为达到充分脱除CO2的目标，我们将已配好设定浓度的稀氨水从吸收塔顶部喷淋，与塔底上升的人工烟气充分混合。试验结果证明：氨法相对于传统的脱碳方法，比如物理吸收法，化学吸收法，膜分离法，低温法具有很大优势，只要反应条件控制在合理的范围内可以实现很高的脱碳效率(95%～99%) 及脱除速度。氨水的吸收能力为0.34mol CO2/mol NH3，相应的质量比为0.87，高于传统的MEA方法的0.36。结果显示，温度对CO2的脱除率具有很大影响，在 33℃左右脱碳效率最高。增大稀氨水的浓度，减小进口气体CO2浓度也有利于提高脱除率。反应产物经X光衍射分析证明为碳酸氢铵，是在国内应用很广泛的化肥，具有商业价值。更多还原

【Abstract】 The gaseous pollutants emission control in coal combustion process is the essential requirement for the harmfulness mitigation from acid rain, greenhouse effect, and ozone depleting, and also for the sustainable development. Ammonia (NH3) has shown its effectiveness and advantage in pollutants reduction.The research work includes two parts: 1.experimental study of sulfur dioxide removal from flue gases by ammonia injection; 2.experimental study of carbon dioxide removal from flues gases by ammonia scrubbing. A set of experimental equipment was designed to remove several gas pollutants in power plant by ammonia. By this experimental equipment, we can have experimental study of CO2 and SO2 removal respectively.In the desulfuration experiment, we removed SO2 from the artificial flue gases by ammonia and water vapor injection. The factors, especially the key one which affects the removal efficiency and reaction dynamics were collected and analyzed. The results show: that the method of ammonia injection is effective to control SO2 emission. At all the operating temperature, the SO2 reduction ratio was more than 60%. The more chemical reaction time was needed for reaching a steady ratio at higher temperature. The reduction ratio was still high when the temperature was higher than 80℃. The reaction time for SO2 removal was almost the same in the temperature window of 40℃~85℃. On the basis of experimental results, the suggestion was given in this report that the process temperature should be controlled below 60℃ or even lower in the actual installation for SO2 reduction by NH3 injection.In the second part, in order to remove CO2 thoroughly, the diluent ammonia solution was sprayed from the top of the absorption column, fully mixing with the artificial flue gases from the bottom. The results demonstrate: the method of ammonia excels the traditional ones including physical absorption, chemical absorption, membrane separation and cryogenics method for it can reach a high removal efficiency (from 95% to 98%) and a rapid removal rate under a proper reaction condition. The ammonia scrubbing capacity can be calculated to be 0.34mol CO2/1mol NH3 or 0.87kg CO2/1kg NH3, which is higher than that of MEA method. Results also indicate that temperature plays a key role in the CO2 removal and at<WP=6>about 33℃,the efficiency reaches its highest. The CO2 removal efficiency will improve with decreasing of the CO2 concentration and increasing of ammonia solution concentration. It is proved that ammonium bicarbonate is the main product of the CO2 -NH3 reaction in this study. Ammonium bicarbonate is a cheap, widely used fertilizer in China and has business value.更多还原