Migration and Transformation of Ash-Forming Elements during Steam Gasification of Biomass and Polyethylene

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• 作者：Tianhua Yang ; Fei Liu ; Rundong Li ; Xingping Kai ; Kai Jia ; Yang Sun
• 刊名：Energy & Fuels
• 出版年：2015
• 出版时间：July 16, 2015
• 年：2015
• 卷：29
• 期：7
• 页码：4298-4304
• 全文大小：476K
• ISSN：1520-5029

文摘

Corn straw and polyethylene were subjected to steam gasification in a tube furnace at three different temperatures to investigate the migration and transformation of ash-forming elements. Overall, 84% of the alkali metals, 52% of the alkaline earth metals, and 66% of P were water-soluble and were completely volatilized at 750 掳C in the steam gasification process. Of the alkaline earth metals, 26% were organic and were completely volatilized at 850 掳C. A portion of these volatile elements remained in the ash as (SiO₂路K₂O)(l) slag, (SiO₂路Na₂O)(l) slag, Ca₉MgK(PO₄)₇, Mg₂P₄O₁₂, Mg₂SiO₄, and CaMgSi₂O₆. When the steam gasification temperature reached 750鈥?50 掳C, 54鈥?8% of alkali metals, 45鈥?3% of alkaline earth metals, and 50鈥?8% of P were released into the gas phase. Water-soluble Cl (91%) and S (55%) as well as organic Cl (9%), S (7%), and P (10%) were completely released at 750 掳C, whereas 29鈥?2% of the insoluble S was released as gaseous sulfur. Fe and Al were relatively stable throughout the gasification process. Over 87% of Si was in the eutectic composition and was present as cristobalite. When the temperature increased, crystalline Si transformed into amorphous Si.