Regeneration process of sulfur sorbent based on zinc alumotitanate

Visokotemperaturna desulfurizacija plinova je najvažniji proces za uklanjanje sumporovodika iz vrućih plinova. Vodeći regenerabilni sorbensi za desulfurizaciju, trenutno se temelje na sustavu cinkova titanata (ZnO – TiO2). U ovom radu sorbens na bazi cinkova titanata modificiran je dodatkom aluminijeva oksida (Al2O3) kako bi se osigurala unaprijedila visokotemperaturna mehanička svojstva. Sorbensi sastava Zn(2-x)Al2xTi(1-x)O4 (x = 0, 0,25, 0,5, 0,75, 1) su pripremljeni sol – gel procesom slijeđenim termičkom obradom. Sorbensi su sinterirani u umjerenim uvjetima (500 °C, 2h). Ovisno o početnom molarnom omjeru ZnO:TiO2:Al2O3 nastale su kristalne faze: cinkit (ZnO), brukit (TiO2) i čvrsta otopina spinelne strukture. Učinak sorbensa u sulfurizaciji je ispitan novom procedurom koja se sastoji od šaržnog sulfurizacijskog procesa. Utvrđeno je kako sorbens sa sastavom Zn1.75Al0.5Ti0.75O4 posjeduje najveću sulfurizacijsku reaktivnost, odnosno najveću učinkovitost uklanjanja sumpora.High temperature gas desulfurization is the main process for hydrogen sulphide removal from hot gases. Curently leading regenerable desulfurization sorbens are based on zinc titanate (ZnO – TiO2) system. In this work zinc tiatanate based sorbent was modifyed by aluminium oxide (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. Sorbents were sintered at moderate sintering conditions (500 °C, 2h). Depending on the initial ZnO:TiO2:Al2O3 molar ratio, Zincite (ZnO), brookite (TiO2) as well as solid solution with spinel structure were formed. The sorbent sulphidation performance was tested using newly developed procedure compriring batch sulphidation process. Sorbent with composition Zn1.75Al0.5Ti0.75O4 was found to possess the highest sulphidation reactivity, i.e. sulphur removal efficiency