Abstract The large amount of NOx emitted from ships causes great harm to the environment and to health. Due to the strict regulations on NOx emission, it is urgent to develop a marine NOx absorption technology with efficient NOx removal and less nitrate residue in scrubber water. This paper proposed a novel composite Na2SO3/(NH2)2CO absorption system that could efficiently absorb NOx from ships. The NOx absorption process was studied in combination with a bubble reactor. Na2SO3 could react with NOx to convert the N into nitrite and N2, and (NH2)2CO could reduce the nitrate, nitrite, and NOx to N2. The main key parameters such as Na2SO3 concentration, (NH2)2CO concentration, SO2 concentration, oxygen concentration, NOx oxidation degree, initial NOx concentration, initial pH, and temperature were investigated experimentally. The Na2SO3 concentration had great effects on the NOx absorption efficiency. The nitrate concentration was significantly affected by the absorbents concentration, the NOx oxidation degree, the temperature, and the O2 concentration (0%–8%). Acid condition was not conducive to NOx absorption. A NOx absorption efficiency of 92.3%, a nitrate content of 13.1 mg/L, and the nitrite content of 21.3 mg/L were achieved under the optimal conditions in which, Na2SO3 was 0.25 mol/L, (NH2)2CO was 0.4 mol/L, SO2 was 700 ppm, NOx oxidation degree was 20%, initial NOx was 1000 ppm, and O2 was 12%. The Na2SO3/(NH2)2CO absorption system satisfied the regulations on NOx removal efficiency and nitrate concentration of scrubber water and therefore showed excellent application prospects on ships.

中文翻译：

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在气泡反应器中使用 Na2SO3/尿素复合吸收剂从模拟气体中去除海洋 NOx 的前瞻性吸收系统

摘要 船舶排放的大量NOx对环境和健康造成极大危害。由于对NOx排放的严格规定，迫切需要开发一种高效去除NOx、洗涤器水中硝酸盐残留量少的船用NOx吸收技术。本文提出了一种新型的复合 Na2SO3/(NH2)2CO 吸收系统，可以有效地吸收船舶中的 NOx。结合气泡反应器研究了 NOx 吸收过程。Na2SO3 可以与 NOx 反应将 N 转化为亚硝酸盐和 N2，而 (NH2)2CO 可以将硝酸盐、亚硝酸盐和 NOx 还原为 N2。通过实验研究了Na2SO3浓度、(NH2)2CO浓度、SO2浓度、氧气浓度、NOx氧化度、初始NOx浓度、初始pH值和温度等主要关键参数。Na2SO3 浓度对 NOx 吸收效率有很大影响。硝酸盐浓度受吸收剂浓度、NOx 氧化程度、温度和 O2 浓度（0%–8%）的显着影响。酸性条件不利于NOx 吸收。在Na2SO3为0.25 mol/L、(NH2)2CO为0.4 mol/L的最佳条件下，NOx吸收效率为92.3%，硝酸盐含量为13.1 mg/L，亚硝酸盐含量为21.3 mg/L。 L，SO2为700ppm，NOx氧化度为20%，初始NOx为1000ppm，O2为12%。Na2SO3/(NH2)2CO吸收系统满足洗涤器水中NOx去除效率和硝酸盐浓度的规定，在船舶上具有良好的应用前景。硝酸盐浓度受吸收剂浓度、NOx 氧化程度、温度和 O2 浓度（0%–8%）的显着影响。酸性条件不利于NOx 吸收。在Na2SO3为0.25 mol/L、(NH2)2CO为0.4 mol/L的最佳条件下，NOx吸收效率为92.3%，硝酸盐含量为13.1 mg/L，亚硝酸盐含量为21.3 mg/L。 L，SO2为700ppm，NOx氧化度为20%，初始NOx为1000ppm，O2为12%。Na2SO3/(NH2)2CO吸收系统满足洗涤器水中NOx去除效率和硝酸盐浓度的规定，在船舶上具有良好的应用前景。硝酸盐浓度受吸收剂浓度、NOx 氧化程度、温度和 O2 浓度（0%–8%）的显着影响。酸性条件不利于NOx 吸收。在Na2SO3为0.25 mol/L、(NH2)2CO为0.4 mol/L的最佳条件下，NOx吸收效率为92.3%，硝酸盐含量为13.1 mg/L，亚硝酸盐含量为21.3 mg/L。 L，SO2为700ppm，NOx氧化度为20%，初始NOx为1000ppm，O2为12%。Na2SO3/(NH2)2CO吸收系统满足洗涤器水中NOx去除效率和硝酸盐浓度的规定，在船舶上具有良好的应用前景。酸性条件不利于NOx 吸收。在Na2SO3为0.25 mol/L、(NH2)2CO为0.4 mol/L的最佳条件下，NOx吸收效率为92.3%，硝酸盐含量为13.1 mg/L，亚硝酸盐含量为21.3 mg/L。 L，SO2为700ppm，NOx氧化度为20%，初始NOx为1000ppm，O2为12%。Na2SO3/(NH2)2CO吸收系统满足洗涤器水中NOx去除效率和硝酸盐浓度的规定，在船舶上具有良好的应用前景。酸性条件不利于NOx 吸收。在Na2SO3为0.25 mol/L、(NH2)2CO为0.4 mol/L的最佳条件下，NOx吸收效率为92.3%，硝酸盐含量为13.1 mg/L，亚硝酸盐含量为21.3 mg/L。 L，SO2为700ppm，NOx氧化度为20%，初始NOx为1000ppm，O2为12%。Na2SO3/(NH2)2CO吸收系统满足洗涤器水中NOx去除效率和硝酸盐浓度的规定，在船舶上具有良好的应用前景。初始 NOx 为 1000 ppm，O2 为 12%。Na2SO3/(NH2)2CO吸收系统满足洗涤器水中NOx去除效率和硝酸盐浓度的规定，在船舶上具有良好的应用前景。初始 NOx 为 1000 ppm，O2 为 12%。Na2SO3/(NH2)2CO吸收系统满足洗涤器水中NOx去除效率和硝酸盐浓度的规定，在船舶上具有良好的应用前景。