Soft-templating pathway to create nanostructured Mg–Al spinel as high-temperature absorbent for SO 2

Interest in reducing SO 2 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 (MgAl 2 O 4 ) 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, N 2 sorption, TG, FTIR, SEM, and TEM methods. Mesoporous nanostructured MgAl 2 O 4 with a high surface area of 324 m 2 g −1 were obtained. The organic components contributed to the development of mesoporosity, functioning as a soft template. SO 2 adsorption tests showed that the nanostructured MgAl 2 O 4 had a 51.58 % increase of SO 2 sorption capacity than MgAl 2 O 4 prepared without glucose. These results showed that the nanostructured MgAl 2 O 4 is a promising candidate as catalyst for flue gas desulfurization in FCC process. Three kinetic models were also applied to analyze the SO 2 adsorption kinetics; the pseudo-second order kinetic model fit well with a correlation coefficient (R 2 ) of 0.991 for nanostructured MgAl 2 O 4 .