User:Tclidandan/N2O recovery

Nitric oxide (NO), emitted from coal combustion and transportation, is hazardous to the environment and human health. To address this issue, current chemical methods such as Selective Catalytic Reduction (SCR) and Selective Non-Catalytic Reduction (SNCR) have been widely and extensively employed for NO removal. However, these methods have the disadvantages of high-temperature operation (>300 ◦C), expensive catalysts, and secondary pollution formation, which necessitate the exploration of promising alternatives. A two-step system combining chemical adsorption and biological denitrification has been developed to remove NO from flue gas. The NO is absorbed by Fe(II)EDTA and forms stable metal-nitrosyl complexes Fe(II)EDTA-NO. Denitrifying bacteria can then reduce Fe(II)EDTA-NO, resulting in the production of N2 as the end product and N2O as an intermediate. N2O is recognized as a greenhouse gas with a high global warming potential (310 times that of CO2) and is also considered an ozone-depleting gas. However, N2O is also a renewable energy source with a positive enthalpy of formation and releases 82 kJ/mol of energy when decomposed at 850 ◦C. Additionally, N2O has been used to enhance the engines of high-performance vehicles and as a powerful oxidant for hybrid rockets (Scherson et al., 2013). Furthermore, N2O is utilized in chemical synthesis, as an additive in food, and in medical care. Based on the annual consumption of fuel (5.5 billion tons) (Conti et al., 2016), the global emission of NO from coal combustion is estimated to be 18.8 million tons. Therefore, the recovery of energy from flue gas may have considerable potential