Reactive adsorption desulfurization coupling aromatization on Ni/ZnO-Zn6Al2O9 prepared by ZnxAly(OH)2(CO3)z·xH2O precursor for FCC gasoline

Abstract

Aiming to improve the reactive adsorption desulfurization (RADS) performances of Ni/ZnO adsorbents, ZnxAly(OH)2(CO3)z•xH2O precursor is synthesized by coprecipitation of Zn2+, AlO2−, and CO32−; the ZnO-Zn6Al2O9 composite oxides are obtained by the calcination of ZnxAly(OH)2(CO3)z•xH2O precursor, and the Ni/ZnO-Zn6Al2O9 (6.0 wt% NiO) adsorbents are prepared by wetness impregnation method. The phase, acid strength, acid type and quantity, morphology, and thermal properties were characterized by X-ray diffraction, temperature-programmed desorption of ammonia, pyridine-adsorbed infrared spectrum, high-resolution transmission electron microscopy, and Thermo Gravimetry-Derivative Thermo Gravimetry (TG-DTG), respectively. The breakthrough sulfur capacities of six adsorbents are between 34.2 and 47.9 mg/gcat. The kinetic studies indicated that the active energy of RADS (49.4 kJ/mol) could reach nano-sized ZnO, the particle size of is about 12.0 nm. All the excellent RADS performances can be due to the high SBET. Also, there are some extents of aromatization reactions that occur, which can be contributed to the Bönsted acid rooted in Zn6Al2O9 composite oxide, and the octane number of products can be preserved well.