Study On The Combining Process Of Complex Denitrifying And Hydrofining Treating Diesel Of Low Quality

Today the clean diesel oil instead of gasoline used as the primary transportation fuels hasbecome a trend due to energy shortage and environmental pollution. Expanding use of diesel depends greatly on the deep desulfurization technology and the deep desulfurization of diesel fuels by combining technology of complex denitrifying and hydrofining which possessing the advantages of simple process routes, mild operation conditions and lower cost becomes an active research field. As the basis research for the industrialization of combining desulfurization technology, this thesis focused on the study of the preparation of a complex denitrifying agent used to treat coking diesel and modifieding the hydrogen catalyst carrier.Based on the review of the references, the complex denitrifying agent were prepared considering two aspects: solvents and the complex agent.Static denitrifying method was referred to evaluate the denitrifying agent properties.The experiment results were showed that the complex denitrifying agent which was composed of iron trichloride,phosphoric acid and propanetriol was tested to be the best. The rate of removing nitrides was 82.35% when the dose-oil ratio was 1:100.And the effects of the components of the denitrifying agent were studied. The conditions of the denitrifying process are superiored further more by the orthogonal design method.The excellentest conditions are defined.They are reaction temperature 85℃,reaction time 30min, subsidence time 60min and dose-oil ratio1:100.Meanwhile the thesis is also developed a kind of hydrofining catalyst and optimized the hydrofining process. The pore structure of the supporter is improved by an auxiliary agent A added. The hydrofining catalyst is preparared successfully .the conditions of the hydrofining process are superiored.The excellentest conditions are defined.they are reaction temperature 360℃,reaction pressure 8.0MPa,space velocity 1.0h-1 and H-oil ratio 500:1.When the denitrifying agent and process as well as the hydrofining catalyst and process are defined,the thesis is also developed the combining process of complex denitrifying and hydrofining to treat the diesel of low quality. 100ml contrasting hydrogenation experiments were accomplished to use developed catalyst.The evaluated results were indicated the foaming diesel of hydrogenation of the material of the blend of coking denitrifying diesel and catalytic diesel changed obviously that the content of sulphides, nitrides, aromatic hydrocarbons and cetane number were excellent. the sulphides amounts of the foaming diesel of hydrogenation reduced from 18.24μg/g to 7.32μg/g.It decreased 10.92μg/g.The aromatic hydrocarbons of the foaming diesel of hydrogenation reduced from 28.5% to 21.10%.It decreased 7.4%.The cetane number rose from 47.50 to 52.50.It increased 5.0.So,it further removed the sulphides and the aromatic hydrocarbons using Combining process of the complex denitrifying and hydrofining after it removed the nitrides. The foaming diesel of hydrogenation achieved the clean diesel oil of the low sulphides and aromatic hydrocarbons standard completely.