FCC硫转移剂MgAlCuFe复合氧化物的结构与性能：Fe和Cu含量的影响

Structure and Properties of MgAlCuFe Complex Oxide for FCC Desulfurization:Effect of Fe and Cu Contents

采用共沉淀法合成MgAlCuFe水滑石前驱体,经过700℃焙烧6h后,制备了一系列不同Fe和Cu含量的FCC硫转移剂.利用X射线衍射、氮气吸附和X射线荧光光谱对硫转移剂的结构和组成进行了表征,采用改装的WRP-3热重天平分析了其氧化吸硫和还原脱硫的性能.结果表明,在一定范围内调变Fe和Cu含量均可以得到结构规整的类水滑石前驱体,经过焙烧后得到MgAlCuFe-LDOs复合氧化物.最佳的Fe和Cu含量分别为8%和1%,其吸硫速度较快,仅6min即达到吸附饱和1.57g/g,还原脱硫的效果也较好.在MgAlCuFe-LDOs复合氧化物中Fe是氧化SO2和还原MgSO4的促进剂,Cu具有促进催化氧化SO2的能力.

A series of MgAlCuFe complex oxides with various Fe and Cu contents used for the removal of SOx from FCC flue gas were prepared by calcination of MgAICuFe hydrotalcite precursors at 700 ℃ for 6 h. The influence of metal contents in the sulfur transfer catalyst was investigated by X-ray diffraction, N2 adsorption, and X-ray fluorescence spectrometer analysis. The results show that all the sulfur transfer catalysts exhibited a better dispersion of metal oxides in the matrix. The results of SO2 adsorption-reduction tests indicate that the catalyst Cu1 % Fe8 %-LDOs had a total saturation adsorption capacity of 1.57 g/g in 6 min and a large reductive capacity under the conditions similar to those of a typical FCC. In the MgAlCuFe-LDOs, Fe played a dual role as an oxidizing and a reducing promoter, and Cu was an efficient promoter for oxidizing SO2 to SO3.