福建无烟粉煤纸浆黑液富氧流化床催化气化研究

福建无烟粉煤纸浆黑液富氧流化床催化气化研究

  • 摘要: 在实验室小型流化床反应器中研究了福建龙岩无烟粉煤纸浆黑液富氧催化气化的特性,考察了纸浆黑液催化剂添加量不同时氧体积分数变化对碳转化率、产气率、煤气组成与热值的影响。结果表明,纸浆黑液催化和富氧气体燃烧的双重作用明显地提高了煤的碳转化率和煤气有效组成;纸浆黑液中钠碱对煤焦气化的催化与对煤灰分中SiO2和Al2O3等氧化物的熔制反应同时发生并存在着竞争;纸浆黑液中钠碱对高温碳与气化剂之间多种反应表现出不同程度的促进。龙岩无烟粉煤在纸浆黑液富氧催化气化时适宜操作条件是氧的体积分数40%和蒸汽/富氧比为1.4kg/m3~2.0kg/m3。碳转化率94%、煤产气率为3.62m3/kg、煤气热值为7.33mJ/m3。

     

    Abstract: The experiments on the catalytic gasification of pulverized Fujian Longyan anthracite by using black liquor as the catalyst and oxygen enriched mixing gas (oxygen enriched air/steam) as the gasification medium were carried out in a bench-scale fluidized bed reactor. The effects of catalyst (black liquor) addtive on the carbon conversion, gas yield, gas composition and calorific value were evaluated under different enriched oxygen concentrations. The results show that the dual effects of the black liquor catalyst and the enriching of oxygen in feed air can greatly improve the carbon conversion and the effective composition of gas products. However, the catalytic gasification of coal by alkali in black liquor and the calcination (vitrification) reactions of SiO2 and Al2O3 in coal ash with alkali in black liquor coexist in the same process, and these reactions exhibit a certain competition at 870℃. In addition, a series reactions between carbon and gas medium at high temperature may be enhanced differently by alkali in black liquor. Based on the experimental results and above analysis the optimum operation condition for the black liquor catalyzed gasification of Fujian Longyan anthracite in enriched oxygen medium is proposed. The oxygen concentration of 40% and the ratio of steam to oxygen enriched air ranging from 1.4kg/m3 to 2.0kg/m3 will have the best results,such as 94% of carbon conversion, 3.62m3/kg of gas yield and 7.33MJ/m3 of calorific value of gas products.

     

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