柴油催化氧化深度脱硫研究

Deep Desulfurization of Diesel Fuels by Catalytic Oxidation

以二苯并噻吩(DBT)代表柴油中的有机硫化合物,将其溶解于正辛烷配成反应原料,以30%过氧化氢溶液为氧化剂,考察了饱和吸附DBT活性炭在甲酸存在下的催化性能,并且研究了活性炭加量、甲酸浓度、过氧化氢初始浓度、DBT初始浓度及反应温度对DBT氧化的影响。实验结果表明:H2O2-HCOOH-活性炭三元体系产生的羟基自由基和过氧甲酸能将模型有机硫化合物氧化,二苯并噻吩的氧化脱硫率可达到100%;活性炭-甲酸的催化氧化性能明显优于单纯使用甲酸。甲酸浓度、活性炭加量、过氧化氢初始浓度及反应温度对二苯并噻吩的氧化脱除均有影响。随着DBT初始浓度的增加,氧化深度脱硫难度增加。

Dibenzothiophene （DBT） was selected to represent the organosulfur compounds in diesel fuel, and in the deep desulfurization experiments, the solution of DBT dissolved in n-octane was used to model the diesel fuels containing organosulfur compounds, and the 30%（wt） aqueous solution of H2O2 was used as oxidant. The catalytic performance of the activated carbon （AC） saturated with DBT was studied in the present of formic acid. The effects of different kinds of AC and its used dosage, the concentration of formic acid, the initial concentration of H2O2, initial concentration of DBT and the reaction temperature on oxidation of DBT were investigated. The experimental results show that the combination of AC with formic acid has a better catalytic performance than that of formic acid only, and the hydroxyl free radicals and the peroxyformic acid produced in the H2O2-HCOOH-AC ternary system can synergically oxidize DBT with a conversion of 100%. The results also show that the concentration of formic acid, dosage of used AC, initial concentration of H2O2 and reaction temperature affect the oxidative removal of DBT, and the higher the initial concentration of DBT in n-octane solution, the more difficult for its deep desulfurization by oxidation.