Use of High-Pressure Impregnation in Preparing Zn-Based Sorbents for Deep Desulfurization of Hot Coal Gas

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• 作者：Xianrong Zheng ; Weiren Bao ; Qingmai Jin ; Liping Chang ; Kechang Xie
• 刊名：Energy & Fuels
• 出版年：2011
• 出版时间：July 21, 2011
• 年：2011
• 卷：25
• 期：7
• 页码：2997-3001
• 全文大小：816K
• 年卷期：v.25,no.7(July 21, 2011)
• ISSN：1520-5029

文摘

A new preparation method of zinc oxide (ZnO) sorbents for removing H₂S from hot coal gas was explored. High-pressure impregnation with semi-coke as the support and zinc nitrate as the active component precursor was used to prepare Zn-based sorbents (HZnSC). The desulfurization activity of the sorbents was studied in a fixed-bed reactor under the simulated coal gas mixture of CO (33 vol%), H₂ (39 vol %), H₂O (5 vol %), H₂S (300 ppmv), and N₂ (balance) at 300鈥?50 掳C. The results show that the desulfurization activity of the HZnSC sorbents is higher than that of the sorbents prepared using atmospheric pressure impregnation. The surface area of the semi-coke expanded from 16.65 to 272.59 m²/g. Nanoscale ZnO was acquired, and the active component was uniformly dispersed on the support with the high-pressure impregnation method, which afforded H₂S removal from hot coal gas. HZn20SC (prepared with 20 wt % zinc nitrate solution) reduced H₂S from 300 to less than 0.1 ppmv at 300鈥?50 掳C, and its sulfur capacity was 4.5 g of S/100 g of sorbent at 500 掳C. It also maintained good heat stability during three desulfurization/regeneration cycles. The findings suggest that semi-coke with a low surface area can be used as a support of sorbents to remove H₂S from hot coal gas using high-pressure impregnation.