Effects of acidic gases and operation parameters on denitrification in oxy-fuel CO2 compression process
Effects of acidic gases and operation parameters on denitrification in oxy-fuel CO2 compression process
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DOI：
10.1016/j.fuel.2018.07.151
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发表时间：
2018-12
期刊：
影响因子：
7.4
通讯作者：
Xiaoshan Li;Qiang Huang;Cong Luo;Zewu Zhang;Yongqing Xu;Liqi Zhang;C. Zheng
中科院分区：
文献类型：
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作者：
Xiaoshan Li;Qiang Huang;Cong Luo;Zewu Zhang;Yongqing Xu;Liqi Zhang;C. Zheng
富氧燃烧技术作为一种技术上可行的方法，具有很大的潜力，以显着减少燃煤电厂的CO2排放。在富氧燃烧系统中，SO2和NOx等气体杂质会对CO2压缩和净化装置（CPU）造成潜在的腐蚀风险，因此必须在CO2回收前去除。在现有的CO2 CPU系统中同时去除SO2和NO是一个有吸引力的策略，以取代传统的烟气处理装置。由于NOx中90%以上是不溶性NO，因此NO的脱除备受关注。在加压反应系统上对CO2压缩过程中NO的脱除效率进行了实验研究。考察了酸性气体（SO2、CO2）和操作参数（压力、温度、初始O2浓度和停留时间）对反应的影响。在加压反应体系中，通过O2的存在将NO氧化为NO2，再通过水中吸收实现NO的脱除。NO转化为NO2是NO脱除的关键步骤，其转化率与压力呈正相关，与温度呈负相关。在2.0 MPa下，加入1000 ppm的SO2，NO去除率降低了8.1%。SO2与NO2的气相和液相反应表明，部分NO2在与SO2反应时转化为不溶性NO。O2/CO2气氛下的NO去除率略高于O2/N2气氛下。CO2在水中的溶解增加了水溶液的停留时间和酸度，有利于NO的氧化。
Oxy-fuel combustion technology has great potential as a technically feasible method to significantly reduce CO2emissions from coal-fired power plants. In an oxy-fuel combustion system, gas impurities such as SO2and NOxmust be removed before CO2recovery because they can cause potential corrosion risk to CO2compression and purification units (CPU). An attractive strategy is to simultaneously remove SO2and NOxin the existing CO2CPU system in place of traditional flue gas treatment device. Since NOxcontains more than 90% of insoluble NO, the removal of NO has attracted much attention. In this study, NO removal efficiency in CO2compression process were experimentally investigated on a pressurized reaction system. Effects of acidic gases (SO2, CO2) and operation parameters (pressure, temperature, initial O2concentration and residence time) were taken into consideration. NO removal was achieved in pressurized reaction system as a result of oxidation to NO2in the presence of O2and the absorption of NO2in water. NO conversion to NO2was the key step for NO removal, which was strongly and positively dependent on the pressure and negatively dependent on the temperature. With the addition of 1000 ppm SO2in simulated gases, NO removal efficiency was reduced by 8.1% at 2.0 MPa. The gas phase and liquid phase reactions between SO2and NO2suggested that partial NO2was converted to insoluble NO when reacting with SO2. It was also found that NO removal efficiency in O2/CO2atmosphere was slightly higher than that in O2/N2atmosphere. The dissolution of CO2in water increased the residence time as well as the acidity of the aqueous solution, which could facilitate the oxidation of NO.