Experimental Study on the Characteristics of Self-Desulfurization during Sugarcane Leaf Combustion in a Circulating Fluidized Bed

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• 作者：Chunjiang Yu ; Jisong Bai ; Hu Nie ; Lianming Li ; Qinhui Wang ; Zhongyang Luo
• 刊名：Energy & Fuels
• 出版年：2011
• 出版时间：September 15, 2011
• 年：2011
• 卷：25
• 期：9
• 页码：3885-3891
• 全文大小：858K
• 年卷期：v.25,no.9(September 15, 2011)
• ISSN：1520-5029

文摘

During biomass combustion, the SO₂ emission would still be a problem in some cases, although the average sulfur content is relatively lower than that of coal and other fossil fuels. In this work, the characteristics of self-desulfurization during sugarcane leaf combustion in a circulating fluidized bed were experimentally investigated. First, a laboratory fixed-bed reactor was used to study how the char particles take part in the self-desulfurization process. It was observed that SO₂ can be largely captured by char in the temperature range of 700鈥?00 掳C. Most of the captured sulfur was incorporated with organic char matrix rather than directly retained by inherent alkali and alkaline-earth matters in the form of inorganic salts. During char combustion, substantial amounts of the captured sulfur could be retained in the ash, which was mainly limited by the alkali and alkali-earth matters available. At higher temperatures (>800 掳C), the sulfur retention reduced, mainly because the alkali and alkali-earth matters would give priority to form silicate compounds rather than the occurrence of sulfate reactions. Then, a pilot-scale circulating fluidized-bed experiment was performed to study SO₂ emission behaviors during sugarcane leaf combustion. It showed that there was nearly no SO₂ emission when the combustion temperature was controlled below 800 掳C. The sulfur retention calculation based on ash balance showed that about 87% of fuel S was retained in fly ash. This was mainly attributed to the intense gas鈥搒olid contact within the combustor that could largely enhance the sulfur retention reactions.