摘要
采用水洗法回收孙家壕(SJH)高铝煤焦Na_2CO_3催化气化灰渣中的钠催化剂,结合ICP和XRD表征方法,研究了高铝煤焦气化催化剂的失活规律和回收特性。在高铝煤焦催化气化过程中,Na_2CO_3与煤中矿物质发生反应生成NaAlSiO_4是造成Na_2CO_3催化剂失活的原因。以水为溶剂回收不同Na_2CO_3负载量的煤焦气化灰渣中的钠催化剂时,钠催化剂的回收率随着Na_2CO_3负载量的增大而增大。当用盐酸回收时,钠催化剂的回收率显著增加,表明相当一部分钠生成不溶于水但可溶于盐酸的NaAlSiO_4。钠催化剂的最大失活量相当于9%Na_2CO_3负载量。
The deactivation mechanism and recovery characteristics of gasification catalyst are investigated through the recovery of sodium-based catalyst from Na_2CO_3-catalyzed gasification residues of Sunjiahao(SJH) high-aluminum coal char with water leaching method combined with ICP and XRD characterization.Na_2CO_3 reacts with the minerals in coal char to form NaAlSiO_4 during the catalytic gasification process of high-aluminum coal char,leading to the deactivation of Na_2CO_3 catalyst. The recovery rate of sodium-based catalyst increases with the increment of Na_2CO_3 loading amount in gasification process when water is used as recovery solvent to recover sodium-based catalyst from ash residues generated in the catalytic gasification of SJH char with different Na_2CO_3 loading amount. The recovery rate is remarkably higher when diluted hydrochloric acid is used as extraction agent,suggesting that substantial sodium forms NaAlSiO_4 that is water insoluble but soluble in hydrochloric acid. Moreover,the deactivation amount of sodium catalyst reaches saturation level when the catalyst loading amount is 9% on the basis of the dry char mass.
引文
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