Relationship Between Hydrocarbons Reaction and Cetane Number in Diesel Hydro-Upgrading

The chemical reaction process of main hydrocarbons in refining stage was investigated with Shilian light cycle oil as feed at hydrogen partial pressure of 10.0 MPa,volume space velocity of 1.14 h-1,hydrogen-oil volume ratio of 1000,reaction temperature of 360℃ in pilot plant.The chemical reaction process of up-grading stage under different reaction temperatures at a hydrogen partial pressure of 10.0 MPa,a volume space velocity of 2.68 h-1,a hydrogen-oil volume ratio of 1000,was also investigated with a constant reaction temperature of 360℃ in refining stage.The results showed that the positive contribution of aromatics hydrogenation saturation to the cetane number was about 18.46 units,the negative contribution of cracking reaction of hydrocarbons with long side-chain to the cetane number was about 1.06 units,and the total cetane number due to the combination of positive and negative effects increased by 17.40 units in refining stage,while the positive contribution of aromatics hydrogenation saturation and ring opening of naphthenic structures to the cetane number was 3.93-6.60 units in up-grading stage,the negative contribution of cracking reactions of hydrocarbons with long side-chain was 0.33-1.19 units in the up-grading stage,and the final cetane number of up-grading product due to the integrative effect of reactions increased only 3.60-5.50 units over refining oil.