Pre-fractionation concept in the scheme of straight—naphtha fractionation

DOI: 10.32758/2071-5951-2021-0-1-24-29

УДК 665.6

Ivanova K.N., Kharlamova M.A., Zuykov A.V.

(OAO «VNIPIneft», Moscow)

Принцип предфракционирования в схеме разделения бензиновой фракции

Keywords: straight-run naphtha distillation, sharpness of separation, benzene content reduction, prefractionation, optimization of separation scheme.

Abstract

The requirements to motor fuels are tightened, in particular, restrictions on the content of hydrocarbons and benzene, with the adoption of new emission standards in the modern oil refining industry.

At many Russian refineries problem of benzene content decreasing in reformate, which is the main component of gasolines, and, consequently, problem of benzene content decreasing in commercial gasoline, is solved by increasing the initial boiling point of the feedstock for catalytic reforming units to 100°C. At the same time, the main benzene-forming components have boiling points up to 85˚С. This approach is explained by the limitations of technological equipment and a significant increase in energy consumption when creating proper sharpness of rectification at CDU units, while it has a negative impact on the refinery economic efficiency.

The article is devoted to approach to modernization of the typical straight-run naphtha distillation unit, configured to the maximum extraction of feedstock for catalytic reforming unit while meeting the requirements imposed on the content of benzene and benzene precursors in it. The proposed solutions can be implemented in the unit current configuration and do not require replacement of main process equipment. Changes in material balance and utility consumption of the unit after described modernization are presented.