Process Of Oxidative Denitrification Of Coking Diesel

The nitrogen compounds in diesel can affect its performance and cause environment problems, furthermore, the hydrodesulfurization process can be seriously inhibited. As the inhibition is more significant when the sulfur content of diesel is less than 100 g/g, it's difficult to produce ultra-low sulfur diesel.In this paper, the influences of the different oxidation systems, the oxidation temperature, the oxidation time, the volume ratio of oxidants and oil, the different extractants, the extraction temperature, the extraction time, the volume ratio of extractants and oil, and the different extraction stages were investigated with the method of oxidative extraction. The optimum oxidative extraction process parameters were identified. Under the optimum operating conditions, the mechanism of Oxidative extraction, the cyclic utilization of used oxidants and extractants, and the influences of the different transition metal ions on the removal of nitrogen in diesel were investigated, such as iron ion, copper ion and aluminum ion. The effects of diesel oxidation stability and color were investigated by storing experiments.The optimal operation conditions are as follow: the system of hydrogen peroxide and formic acid solution as an oxidant, oxidation temperature 70℃, oxidation time 1 min, volume ratio of oxidants to coking diesel 0.24, volume ratio of hydrogen peroxide to formic acid 0.5; furfural as an extractant, volume ratio of extraction to oil 0.8, extracting at room temperature for 5 min. The results show that the yield of diesel fuel is 93.33 %, and the total denitrification rate is 94.69 %. When the extraction stage is four, the total denitrification rate is 98.19 %. Under the optimum operating conditions, the influence of iron ions on the rate of nitrogen removal is better than aluminum ions and copper ions. The Used extractant can be recycled by the distillation unit operation, with a good result. The stability and color of refined diesel are significantly improved.In this paper, we treated diesel products with the method of oxidative extraction. Experimental results show that this method has a significant effect on the removal of trace nitrogen and trace sulfur in the diesel oil under the optimal conditions. The initial nitrogen content of diesel oil is 43.81 ppm, and the initial sulfur content of diesel oil is 1.56 g/L. The results show that the total denitrification rate is 76.39 %, the total desulfurization rate is 87.38 %, and the yield of diesel oil is 93.33 %. The color and stability of diesel are significantly improved. The selectivity of carbazole and thiophene compounds, which are difficult to be removed, is very strong.