Improving simultaneous removal efficiency of SO2 and NOx from flue gas by surface modification of MgO with organic component

Abstract

Using glucose and polyvinylpyrrolidone as raw materials, MgO-organic component materials were prepared by a one-step hydrothermal method. The material is used to improve the efficiency of simultaneous removal of SO2 and NOx, and to reduce the competitive adsorption of both. In the experiments, the adsorption of SO2 and NOx in simulated coal-fired flue gas was tested with MgO-organic component/pure MgO/MgO (PVP modified)/MgO (glucose modified), and the test results were compared. It is very noteworthy that the SO2 dynamic adsorption capacity of the MgO-organic component (the glucose/polyvinylpyrrolidone ratio is 1:3) was 0.3627 mmol/g; while that of NOx was 0.2176 mmol/g, and the adsorption breakthrough time (time taken when the NOx removal rate was 50%) was as long as 60 min (the total flow rate of simulated flue gas is 200 ml/min, the space velocity is 24000 h-1, the reaction temperature is 100 °C, the concentration of SO2 and NOx is 500 ppm and 300 ppm, respectively). In this study, the organic component enhances the simultaneous desulfurization and denitration performance of MgO from three aspects and is verified by different characterization tests. There are an increase in specific surface area, an increase in surface energy and the insert of active functional groups. In particular, the insert of –CO can greatly improve the adsorption efficiency of NOx. Meanwhile, the adsorption process under different operating conditions is discussed in order to provide theoretical support for industrial practice. The work presented here has profound implications for future studies of simultaneous desulfurization and denitration field. Moreover, the economy and sustainability of the technology meet the basic requirements of waste reduction in cleaner production.