Soft-templating pathway to create nanostructured Mg–Al spinel as high-temperature absorbent for SO2

Interest in reducing SO2 emission from the fluid catalytic cracking (FCC) crude oil has been encouraging the development of new materials to achieve such goal. The nanostructured Mg–Al spinel (MgAl2O4) was prepared by co-precipitation and post hydrothermal treatment in the presence of glucose and followed by elimination of the organic components by calcination at 700 °C for 3 h. Physical and chemical properties were characterized by XRD, N2 sorption, TG, FTIR, SEM, and TEM methods. Mesoporous nanostructured MgAl2O4 with a high surface area of 324 m2 g−1 were obtained. The organic components contributed to the development of mesoporosity, functioning as a soft template. SO2 adsorption tests showed that the nanostructured MgAl2O4 had a 51.58 % increase of SO2 sorption capacity than MgAl2O4 prepared without glucose. These results showed that the nanostructured MgAl2O4 is a promising candidate as catalyst for flue gas desulfurization in FCC process. Three kinetic models were also applied to analyze the SO2 adsorption kinetics; the pseudo-second order kinetic model fit well with a correlation coefficient (R2) of 0.991 for nanostructured MgAl2O4.