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High temperature gas desulfurization (HTGD) is the main process for hydrogen sulphide removal from hot gases. Currently leading regenerable desulfurization sorbents are based on ZnO–TiO2 system. This work presents structural and textural modifications of ZnO–TiO2 based sorbents by Al2O3 addition in order to ensure high temperature mechanical support. Sorbents with composition Zn(2-x)Al2xTi(1-x)O4 (x = 0, 0.25, 0.5, 0.75, 1) were prepared by sol-gel process followed by thermal treatment. Nanocrystalline powderswere produced at moderate sintering conditions (500 °C, 2 h). Depending on the initial ZnO:TiO2:Al2O3 molar ratio, zincite (ZnO), brookite (TiO2) as well as gahnite(ZnAl2O4) solid solution were formed. Al2O3 induced textural modifications, rising specific surface area from 34 to 90 m2 g–1. The sorbent sulphidation performance was testedusing newly developed procedure comprising batch sulphidation process. Sorbent with composition Zn1.75Al0.5Ti0.75O4 was

High temperature gas desulfurization (HTGD) is the main process for hydrogen sulfide removal from hot gases. Thus several metal oxide materials have been studied in an attempt to develop regenerable sorbents. Many metal oxides have been evaluated as regenerative sorbents and currently, ZnO–TiO2 based sorbents appear to be leading for desulfurization. High temperature stable metal oxides such as Al2O3 can act as supports for strengthening the mechanical structure and prevent attrition or sintering of the sorbent during the regeneration process. In this work structural and textural modifications of ZnO–TiO2 based sorbents by Al2O3 addition were studied. Five samples with composition Zn(2-x)Al2xTi(1-x)O4, where x was 0, 0.25, 0.5, 0.75 and 1 were prepared. ZnO–TiO2–Al2O3 type sorbents were prepared by sol-gel process followed by calcination at 500 °C for 2 h. The thermal evolution of obtained sorbents has been investigated using differential thermal analysis (DTA) and thermogravimetric analysis (TGA). The crystallization products and structural properties were characterized using powder X-ray diffraction (XRD). The textural properties and pore size has been investigated using low temperature nitrogen adsorption. Nanocrystalline powders were produced at the low sintering temperature of 500 °C and the short sintering time of 2 h. Depending on the initial ZnO:TiO2:Al2O3 molar ratio, zincite (ZnO), brookite (TiO2) as well as gahnite (ZnAl2O4) solid solution were formed. The introduction of Al2O3 also induces textural modifications, causing changes in pore structure and the increase of specific surface area from 34 to 90 m2 g-1. The sorbent sulfidation performance was tested using newly developed procedure comprising batch sulfidation process followed by XRD and TGA analysis and the results obtained are discussed on the basis of structural and textural properties. Sorbent with composition Zn1.75Al0.5Ti0.75O4 was found to possess the highest sulfidation reactivity, i.e. sulphur removal efficiency.

High temperature gas desulfurization (HTGD) is the main process for hydrogen sulphide removal from hot gases. Currently leading regenerable desulfurization sorbents are based on ZnO–TiO2 system. This work presents structural and textural modifications of ZnO–TiO2 based sorbents by Al2O3 addition in order to ensure high temperature mechanical support. Sorbents with composition Zn(2-x)Al2xTi(1-x)O4 (x = 0, 0.25, 0.5, 0.75, 1) were prepared by sol-gel process followed by thermal treatment. Nanocrystalline powders were produced at moderate sintering conditions (500 °C, 2 h). Depending on the initial ZnO:TiO2:Al2O3 molar ratio, zincite (ZnO), brookite (TiO2) as well as gahnite (ZnAl2O4) solid solution were formed. Al2O3 induced textural modifications, rising specific surface area from 34 to 90 m2g-1. The sorbent sulphidation performance was tested using newly developed procedure comprising batch sulphidation process. Sorbent with composition Zn1.75Al0.5Ti0.75O4 was found to possess the highest sulphidation reactivity, i.e. sulphur removal efficiency.