Experimental Study Mn-Ce Series Cryogenic Process Is Based On The SCR Catalyst

Nitrogen oxides(NOx) emiessions have a serious influence on atmospheric environment and human health. Selective Catalystic Reduction (SCR) of NOx is the most widely used technology to reduce NOx from stationary sources because of the higher efficiency. Recently, low temperature selective catalytic reduction technology has attracted more and more interests for its energy conservation and potential application. But the technology research of low temperature SCR are limited in laboratory which focus on the fixed characteristic and the activity of catalyst under the condition of simulating flue gas.The research of low temperature SCR denitration process test under the condition of the power plant flue gas is not yet reported. In view of the above problems, a novel co-precipitation catalyst preparation method was developed and a set of matching low temperature SCR denitration device was designed to study the performance of the Mn-Ce/TiO2in power plant flue gas.In this study, we developed a novel co-precipitation method to prepare Mn-Ce/TiO2catalysts. And compared with the conventional co-precipitation method and impregnation method, it was found that the Mn-Ce/TiO2catalysts prepared by the novel co-precipitation method had much higher activity and SO2resistance. It has obtained over92%of NO conversion when the temperature reached120℃with a gas hourly space velocity (GHSV) of40,000h"1in low temperature SCR denitration reaction.The high concentrations of SO2also caused the significant deactivation of the Mn-Ce/TiO2catalysts which prepared by the novel co-precipitation method. Characterizations of fresh and S02-poisoned Mn-Ce/TiO2catalysts were carried out by BET, XPS and X-ray. The characterized results indicated that the deposition of sulfates and nitrates on the surface made the catalyst deactivated. Water washing, thermal regeneration and reductive regeneration were used to regenerate the deactivated Mn-Ce/TiO2. And it was fonud that water washing showed best performance on the regeneration of poisoned catalysts. A set of continuous water regeneration system was designed to ensure the activity of the Mn-Ce/TiO2catalysts which prepared by the novel co-precipitation method for low-temperature selective catalytic reduction.Based on the high activity and good SO2resistance of Mn-Ce/TiO2catalysts prepared by the novel co-precipitation method,we chose the continuous water washing regeneration system and molding method to match the catalyst industrial application. So in this study we designed a set of industrial feasible denitration low temperature SCR device which was used in the coal-fired power plant at the total flow rate of200m3/h real flue gas and also achieved the expected NO removal efficiency. At the same time it accumulated a wealth of experimental data which lay the foundation for the low temperature SCR denitration technology industrial application.