Experimental study of hot gas desulphurization with limestone sorbent

Key words: 
• high-temperature desulfurization sorbent /
• limestone /
• hydrogen sulfide /
• coal gasification

Abstract: Natural limestone was adopted as a high-temperature desulfurization sorbent. Tests for removal of H2S with limestone at high temperatures were carried out in a fixed bed reactor. The effects of reaction temperature, gas velocity, particle size and H2 in hot gas on the desulfurization performance were tested. The structure and composition were also studied by thermogravimetry (TG), scanning electron microscopy (SEM) and X-ray diffraction (XRD). It is showed that the particle size has a great influence on desulfurization performance. The limestone of 0.38～0.83 mm has the best desulfurization effect; the temperature has a complicated influence on desulfurization performance, the desulfurization sorbent has the best desulfurization effect at 850℃; gas velocity also has a distinct influence on desulfurization performance, desulfurization breakthrough time becomes longer as the gas velocity decreases; H2 can inhibit the desulfurization process, it is more obvious as the gas velocity decreases.