Patent ID: 7276150

Claim:
A process for desulfurizing a straight-run gas oil fraction, comprising: a low-boiling straight-run gas oil fraction hydrodesulfurization step (I) wherein a low-boiling straight-run gas oil fraction obtained by fractionating a straight-run gas oil fraction into two fractions at a cut point t° C. wherein the cut point satisfies the expression of 280≦t≦360 (° C.) is desulfurized under the conditions of a H 2 /Oil ratio of 70 to 200 Nm 3 /kl and a total pressure of 30 to 70 kg/cm 2 G to obtain a treated oil, a high-boiling straight-run gas oil fraction hydrodesulfurization step (II) wherein a high-boiling straight-run gas oil fraction obtained by fractionating a straight-run gas oil fraction into two fractions at a cut point t° C. is desulfurized under the conditions of a H 2 /Oil ratio of 200 to 800 Nm 3 /kl and a total pressure of 40 to 80 kg/cm 2 G to obtain a treated oil, and a step (III) wherein the treated oil obtained in the step (I) is mixed with the treated oil obtained in the step (II) to obtain the treated oil having a sulfur content of not more than 50 ppm, wherein at least a part of a gas containing unreacted hydrogen in the step (II) is used for the hydrodesulfurization of the step (I), and wherein unreacted hydrogen in the step (I) is not directly used for hydrodesulfurization of the step (II).