二硫化碳对Ni/Al2O3加氢催化剂中毒机理的研究

Study on the Mechanism of Ni/Al2O3 Catalyst Poisoning Caused by CS2

在温度180℃、氢分压2.1 MPa、质量空速2.0 h-1、氢油体积比为300的条件下,考察了二硫化碳对Ni/Al2O3催化剂苯加氢性能的影响,并与二甲基二硫醚、乙基硫醇和噻吩等有机硫毒性进行比较,结果表明,二硫化碳毒性远大于其他三种硫化物。失活催化剂表征结果表明二硫化碳中毒催化剂碳含量为0.21%,远高于其他硫化物中毒催化剂;红外光谱表明催化剂上存在化学吸附的二硫化碳分子;热重-质谱结果表明碳元素至少有两种不同的存在形式。表征结果表明,积碳和硫中毒是造成二硫化碳毒性远大于其他三种硫化物的主要原因。

The poisonousness of CS2 on the Ni/Al2O3 catalyst for preparing low aromatics solvent was studied at180℃,2.1 MPa in a fixed-bed reactor.And its poisonousness was compared with those of organic sulfurs of CH3CH2SH,CH3SSCH3 and C4H4S.The results showed that the sulfur species had a great negative influence to the hydrogenation of benzene and the conversion dropped rapidly with the sulfur accumulation.The poisonousness of CS2was much higher than the others.The deactivated catalysts were characterized by N2 adsorption-desorption,XRD,EA,IR and TG-MS.The results showed that the carbon content of CS2-poinsoned catalyst was 2.1%,which was much higher than the others.IR result showed that partial CS2 was adsorbed on Ni/Al2O3 catalyst in the form of CS2molecule.TG-MS result showed that there were at least two kinds of carbon species on Ni/Al2O3 catalyst.Carbon accumulation and sulfur poisoning were the main reason why CS2 was more poisonous than the others.