Gas phase-liquid phase mixed hydrogenation method

The invention discloses a gas phase-liquid phase circulating mixed hydrogenation method. The gas phase-liquid phase circulating mixed hydrogenation method comprises following steps: inferior diesel oil and hydrogen are subjected to gas phase counter current hydrogenation reaction; obtained liquid oil is mixed with straight-run diesel oil, and an obtained mixture is subjected to saturated hydrogen dissolving, and then is delivered into a liquid phase circulating hydrogenation reactor for reaction; a liquid hydrogenation effluent is divided into two parts, one part is discharged so as to obtain a low-sulfur diesel oil product, and the other part is circulated to a hydrogen mixing tank. According to the gas phase-liquid phase circulating mixed hydrogenation method, after gas phase hydrogenation reaction, aromatic hydrocarbons of the inferior diesel oil are saturated, hydrogen consumption of further reactions is relatively low, and saturated dissolved hydrogen content is increased; and at the same time, a large amount of hydrogen, which is not reacted, is dissolved in the obtained liquid oil, enough dissolved hydrogen is provided for deep desulphurization reaction in the liquid phase circulating hydrogenation reactor, and it is beneficial for performing of deep hydrodesulfurization reaction. The invention provides the novel method used for producing ultra-low sulphur diesel oil by taking inferior diesel oil and straight-run diesel oil as raw materials.