Regeneration of Used Alkali Carbonates for Gaseous Sulfur Removal in a Gasification System

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• 作者：Slamet Raharjo ; Yasuaki Ueki ; Ryo Yoshiie ; Ichiro Naruse
• 刊名：Energy & Fuels
• 出版年：2013
• 出版时间：May 16, 2013
• 年：2013
• 卷：27
• 期：5
• 页码：2762-2766
• 全文大小：356K
• 年卷期：v.27,no.5(May 16, 2013)
• ISSN：1520-5029

文摘

Integrated coal gasification combined cycle is expected to play an important role as one of a number of highly efficient conversion technologies for carbonaceous resources. However, it is vital to remove as much H₂S and COS as possible. Our previous study suggested that the molten alkali carbonates of 43 mol of Na₂CO₃ + 57 mol of K₂CO₃ can completely adsorb them at 1173 K to form alkali sulfides. Furthermore, to enhance the overall efficiency in the gasification system, the regeneration characteristics of the used alkali carbonates should be studied. Therefore, the current study works on that issue. The optimum regeneration condition for experiments was estimated by chemical equilibrium software, FactSage 6.2, prior to the regeneration experiments. Chemical equilibrium calculations suggested that a mixture of carbon dioxide and steam could regenerate the used alkali carbonates. The experiments were conducted in an electrically heated tube reactor using a mixture of CO₂ and steam as the regeneration agent. As a result, the remaining sulfur in solid after regeneration experiments was around 5 mass % of the total sulfur content in the raw sample at an optimum temperature range of 650鈥?73 K. It is expected that around 95% of alkali sulfides was converted back to alkali carbonates.