污泥CaO干化耦合蒸汽气化产气

Gas production by steam gasification coupling with CaO drying of sludge

为提高污泥干化效率并获得高品质气化合成气,研究提出污泥CaO干化耦合蒸汽气化技术。将原始污泥在不同CaO添加比例(0、5%、10%、15%、20%、25%、30%、35%,以质量分数计)下进行干化,并研究不同温度(750、800、850、900℃)下的气化效果,揭示气化机制。在750℃下,添加20%CaO的干污泥气化产生的合成气中H 2纯度最高,为63.28%,产率达154.69 mL/g,低位热值(LHV)为16.15 MJ/m 3,气化冷气效率(CGE)为58.02%。气化温度升至900℃,H 2产率达196.95 mL/g。采用红外光谱(FTIR)仪分析干污泥及其气化后固相产物,结果显示CaO通过促进含氧官能团的分解来提升气化效果。CaO对合成气中CO 2的捕获作用可以驱动水煤气转化反应,提高H 2的产率。

In order to improve the sludge drying efficiency and obtain high-quality syngas,CaO was added for drying sludge and catalyzing steam gasification in this study.The raw sludge was dried with different CaO addition ratios(0,5%,10%,15%,20%,25%,30%and 35%,mass fraction)and the gasification of dried sludge was carried out at different gasification temperatures(750,800,850 and 900℃).The gasification effects were analyzed and the mechanism was revealed under different conditions.Under the gasification temperature of 750℃,the purity of H 2 in the syngas of dried slude(CaO addition ratio was 20%)was the highest,which was 63.28%,and the yield was 154.69 mL/g,the lower heating value was 16.15 MJ/m^3,the cold gas efficiency was 58.02%.As the gasification temperature increased to 900℃,the H 2 yield increased to 196.95 mL/g.FTIR analysis of sludge and char revealed that decomposition of oxygen-function groups were promoted by CaO.Meanwhile,the capture of CO2 by CaO could drive the water-gas shift reaction to increase the yield of H2.