中孔硅胶负载浓硝酸脱除柴油中的硫化物

采取中孔硅胶负载浓硝酸脱除1 000×10~(-6)的4,6-二甲基二苯并噻吩模型柴油中的硫化物,考察反应温度、酸负载量、剂油质量比和吸附剂目数对脱硫效果的影响,并通过红外光谱分析和N_2等温吸附法对硅胶进行表征。结果表明,中孔硅胶具有较大的比表面积、孔体积和合适的孔径;浓硝酸可以负载于中孔硅胶上并将4,6-二甲基二苯并噻吩氧化为砜后吸附在硅胶上。在反应温度45℃、(40~60)目硅胶和硅胶与浓硝酸质量比为1∶0.75条件下脱硫效果最好,剂油质量比为1∶7.5时,脱硫率达93.7%,脱硫后的模型柴油硫含量达到国Ⅴ标准。

Desulfurization of diesel oil over mesoporous silica gel supported concentrated nitric acid

The mesoporous silica gel loaded with dense nitric acid was employed to remove the sulfur in model diesel oil which contained 1 000×10^-6 4,6-dimethyldibenzothiophene.The influence of reaction tempretures,acid loading,mass ratios of catalyst to oil and partical size of the adsorbent on desulfurization effect was investigated.The silica gel was characterized by IR and N₂ adsorption-desorption.The results showed that the mesoporous silica gel possessed larger porous volume,greater specific surface area and suitable porous diameter.Dense nitric acid could be loaded on the mesoporous silica gel and oxidize 4,6-dimethyl dibenzothiophene to sulphone which was adsorbed on silica gel.The desulfurization effect of mesoporous silica gel loaded with dense nitric acid was the best and the sulfur removal efficiency reached 93.7% under the condition of reaction temperature 45 ℃,silica gel (40-60) mesh,mass ratio of silica gel to nitric acid 1∶0.75 and mass ratio of catalyst to oil 1∶7.5.The sulfur content of model diesel oil after desulfurization met the national standard Ⅴ.