# NO Separation Characteristics in Integrated Electromigration Membrane Reactor
## 1 Introduction  
With the frequent occurrence of pollution and the aggravation of resource shortage, pollutant control technology has been investigated from pollution removal to the resource utilization of pollutants [1]. The NOx released from fossil fuel combustion causes bad environmental questions, such as acid rain, haze, and photochemical smog, which are harmful to human health and the ecological environment [2; 3]. At present, the technology of selective non-catalytic reduction denitrification (SNCR) and selective catalytic reduction denitrification (SCR), which reduces NOx emission, shows a high removal efficiency. However, they also are accompanied by some technical difficulties, such as large equipment, air preheater clog, trashy catalyst disposal, and so on [4; 5; 6]. Thus, it has been important to develop new denitrification technologies or improve the existing technology for stricter emission standards [3; 7].  
The membrane gas separation method, which takes the membrane fiber medium as the separation interface, is a new type of gas absorption process with good application prospects. It has the advantages of low-energy consumption, compact structure, simple operation, and strong selectivity, and effectively overcomes the disadvantages of flooding, channeling, and foaming in traditional wet absorption equipment by non-contact between gas and liquid [8]. In recent years, a series of experiments of membrane absorption have been carried out to separate the acid gases of hydrogen sulfide (H\({}_{2}\)S), SO\({}_{2}\), NOx. For example, [PERSON] [9; 10] studied the mass transfer process from the gas phase to liquid phase for H\({}_{2}\)S, SO\({}_{2}\), NH\({}_{3}\), and CO\({}_{2}\) in a membrane absorption reactor and measured the mass transfercoefficients of some gases. [PERSON] et al. [11] studied the removal efficiency of hydrogen sulfide in natural gas by the membrane absorption method under high pressure. [PERSON] et al. [12] researched the feasibility of SO\({}_{2}\) removal by a hollow fiber membrane using seawater as an absorbent, and studied the effect of related parameters on its mass transfer coefficient. [PERSON] et al. [13] analyzed the effect of some parameters on the SO\({}_{2}\) removal efficiency in a membrane contactor. [PERSON] et al. [14] and [PERSON] et al. [15] carried out an investigation on the characteristics of NOx removal by membrane absorption. Among these studies, the transfer of gas molecules through a membrane mainly depends on the concentration difference and the pressure difference of gas in the two sides of the membrane [16], which is accompanied by high gas driving force and large unit gas membrane area for achieving a high gas separation efficiency [8].  
Electromigration, which uses electric field force as the driving force, is an effective separation method to concentrate or separate specific components from the mixture. The method of using electric field force as the driving force has been widely used in industrial production and has shown an excellent technical and economic performance in applications such as electrodialysis, electro-ultrafiltration [17], and electrostatic precipitators [18]. However, few studies have reported enhancing the gas separation efficiency by electromigration in membrane absorption. In view of the above, this paper proposed an integrated electromigration membrane separation process which organically combined plasma technology, electromigration, membrane separation, and chemical absorption. It analyzed the separation mechanism of NO in an integrated electromigration membrane separation reactor. The effect of discharge voltage, gas flow rate, inlet concentration, and absorbents on the separation efficiency and total mass transfer coefficient of NO were discussed. It is hoped that this research can provide new ideas and references for the development of gas separation technology.