用过渡金属改性硅胶吸附剂脱除焦化柴油中的氮化物

摘要

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 x 10-3,23. 205 × 10 -3 and 18. 480 × 10-3 respectively.%将过渡金属离子(Fe<'3+>,Co<'2+>,Ni<'2+>,Cu<'2+>)负载到硅胶上,先制得过渡金属离子改性硅胶吸附剂(Fe(Ⅲ)/SiO<,2>,Co(Ⅱ)/SiO<,2>,Ni(Ⅱ)/SiO<,2>,Cu(Ⅱ)/SiO<,2>),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/SiO<,2>,Co/SiO<,2>,Ni/SiO<,2>.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)/SiO<,2>,Ni/SiO<,2>,Co(Ⅱ)/SiO<,2>,Cu(Ⅱ)/SiO<,2>,Fe/SiO<,2>,Ni(Ⅱ)/SiO<,2>,Co/SiO<,2>;分别用Fe(Ⅲ)/SiO<,2>,Ni/SiO<,2>,Co(Ⅱ)/SiO<,2>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>.