用过渡金属改性硅胶吸附剂脱除焦化柴油中的氮化物

Experimental study on nitride removal from coker diesel by transition metal modified silica gel

将过渡金属离子(Fe3+,Co2+,Ni2+,Cu2+)负载到硅胶上,先制得过渡金属离子改性硅胶吸附剂(Fe(Ⅲ)/SiO2,Co(Ⅱ)/SiO2,Ni(Ⅱ)/SiO2,Cu(Ⅱ)/SiO2),后在氢气环境中和500℃下对过渡金属离子改性硅胶吸附剂进行还原处理,制备出过渡金属改性硅胶吸附剂Fe/SiO2,Co/SiO2,Ni/SiO2。分别在间歇式和连续固定床吸附装置上,以焦化柴油(氮质量分数为2.1×10-3)为原料,在常压下研究了吸附条件对吸附剂脱氮效果的影响。结果表明,最佳吸附温度为120℃,最佳油剂比[m(焦化柴油)/m(吸附剂)]为60;平衡吸附量[m(氮)/m(吸附剂)]由小到大顺序为Fe(Ⅲ)/SiO2,Ni/SiO2,Co(Ⅱ)/SiO2,Cu(Ⅱ)/SiO2,Fe/SiO2,Ni(Ⅱ)/SiO2,Co/SiO2;分别用Fe(Ⅲ)/SiO2,Ni/SiO2,Co(Ⅱ)/SiO2处理焦化柴油,吸附剂的平衡吸附量分别为22.713×10-3,23.305×10-3,18.480×10-3。

The transition metal ions modified silica gel adsorbents Fe（Ⅲ）/SiO2,Co（Ⅱ）/SiO2,Ni（Ⅱ）/SiO2,Cu（Ⅱ）/SiO2 were prepared by loading Fe3＋,Co2＋,Ni2＋ and Cu2＋ on silica gel,and then the transition metal modified adsorbents of Fe/SiO2,Co/SiO2 and Ni/SiO2 were obtained by reducing the metal ion modified species in pure hydrogen at 500℃.The effect of adsorption condition on the nitride removal was investigated using coker diesel with nitrogen mass fraction 2.1×10-3 as feedstock separately in an intermittent absorber and a fixed bed absorber at atmospheric pressure.The results showed that the optimal adsorption condition was temperature 120℃,mass ratio of coker diesel to adsorbent 60.The order of equilibrium adsorption capacity from small to big was：Fe（Ⅲ）/SiO2,Ni/SiO2,Co（Ⅱ）/SiO2,Cu（Ⅱ）/SiO2,Fe/SiO2,Ni（Ⅱ）/SiO2,Co/SiO2.When the coker diesel was treated by Fe（Ⅲ）/SiO2,Ni/SiO2,Co（Ⅱ）/SiO2,the equiblibrium adsorption capacity（mass ratio of coker diesel to adsorbent）was 22.713×10-3,23.205×10-3 and 18.480×10-3 respectively.