| Selective catalytic reduction(SCR)denitration technology is the most widely used technology for flue gas denitrification at present,but it has some defects such as high price and poor denitrification performance at low temperature.So,it is necessary to develop SCR denitrification catalysts with low-cost and high efficient at low-temperature.Metakaolin and water glass were taken as the main materials,geopolyer was prepared,and the regulation of pore structure were studied by cetyltrimethylammonium bromide(CTAB),H2O/Na2O and ultrasound.The suspension polymerization method was used to prepare geopolymers microspheres carrier.Then,the metal oxide modified geopolymer denitration catalyst microspheres(MOGC)was prepared by Mnand Ceion replacement and calcination.The samples were characterized by XRD,SEM,BET,XRF,TEM,etc.,and the catalytic performance of the catalysts was evaluated by simulating the environmental conditions of flue gas emission in the industry.The main results were as follows:1)the increase of H2O/Na2O is propitious to the formation of macropores in the samples,the addition of CTAB is propitious to the formation of 3?5 nm pores.Compared with the sample with a later ultrasound starting time,the large pores size is reduced at 1/2initial setting time,and the longer the ultrasonic duration,the more 3?5 nm gel pores.2)When stirring speed?800 rpm or H2O/Na2O?7.87,the geopolymer had better spherical properties.3)Mnmodified MOGC sample,with the increase of Mnloading,the denitration efficiency increased.The denitration efficiency reaches its maximum value at 160?.At this time,the denitration rate of Mn0.178/MOGC was 62.63%.4)The Mn-Cecomposite modified MOGC has rough surface morphology,Mn2O3and CeO2 can distributed in the geopolymer matrix and inside the pore.With the increase of Celoading,the denitration efficiency increased.Under the experimental conditions of80?240°C,the maximum denitrification efficiency of Ce0.084-Mn0.084/MOGC can reach75.26%.33 pictures;10 tables;71 references. |
PDF Full Text Request