Comparison of desulfurization characteristics of lignite char-supported Fe and Fe–Mo sorbents for hot gas cleaning

• Char-supported iron sorbents showed high desulfurization efficiency.
• Addition of Mo increased the reactivity of char-supported iron sorbents.
• Sulphur capacities of char-supported Fe and Fe–Mo sorbents are compared.
• Simultaneous removal of H2S and COS using Fe–Mo is feasible.

The desulfurization behavior of novel Fe and Fe–Mo sorbents supported using Chinese lignite chars for desulfurization of hot coal gases was investigated and compared. The desulfurization experiments were carried out using a fixed-bed quartz reactor over a temperature range of 673 K to 873 K in simulated coal gas containing 0.47% H2S and 0.047% COS. The product gases composition and chemical phases of sorbents were analyzed using a gas chromatograph and X-ray diffractometer, respectively. The results show that iron and Fe–Mo sorbents supported on lignite char demonstrated high desulfurization efficiency under the present experimental conditions. The sulfur capacity of iron-based sorbents is determined by the amount of iron contained in the sorbents and the addition of Mo into the iron-based sorbents effectively improves the desulfurization efficiency of char-supported iron sorbents.