COS和H_2S毒化F-T合成催化剂热力学分析

Thermodynamics of COS and H_2S poisoning on F-T synthesis catalyst

利用热力学基础数据和相关软件对F-T合成催化剂COS和H_2S中毒的热力学进行了计算。在热力学上,Ru、Fe、Co的COS中毒在F-T合成反应可以发生的条件下均是自发过程。F-T合成反应体系中10^(-9)级的COS即可使Ru基催化剂中的金属Ru生成RuS_2而中毒。Fe和Co毒化后生成的硫化物种类较多,对这些反应的热力学计算结果表明,对于不同的反应,其平衡常数的差异很大,对应中毒反应发生时,所需的COS和H_2S的浓度也不同,对COS的要求更为严格。由于Fe基F-T合成催化剂活性相的复杂性,利用对催化剂相关性质的修饰开发具有一定抗硫性的铁基F-T合成催化剂是可行的;对于Co催化剂,利用F-T合成的反应特点和催化剂改性开发具有一定抗硫性催化剂是可能的。

The thermodynamics of poisoning on F-T synthesis catalyst with carbonyl sulfide and hydrogen sulfide were calculated according to some thermodynamic data and related software. Poisoning of Ru, Fe and Co can occur spontaneously under the conditions of F-T synthesis reaction because of the low negative value of AG thermodynamically. Ruthenium in Ru-based F-T synthesis catalyst can be poisoned by the COS even on 10-9 level. There are many types of Fe and Co sulfide generated in the poisoning reactions. Their equilibrium constants are much different for different reactions, so their necessary concentrations of COS are also different and more stringent requirements on the COS than H2S. As the active phases of the Fe-based F-T synthesis catalyst are complex, it is feasible to develop some sulfur resistant catalysts. And for the Co catalyst, the characteristics of F-T synthesis reaction and the modification of catalysts may contribute to the development of sulfur tolerant catalyst possibly.