Integrated hydrotreating, solvent deasphalting and steam pyrolysis process for direct processing of a crude oil

Abstract

A process is provided that is directed to a steam pyrolysis zone integrated with a hydrotreating zone and a solvent deasphalting zone to permit direct processing of crude oil feedstocks to produce petrochemicals including olefins and aromatics. The integrated hydrotreating, solvent deasphalting and steam pyrolysis process comprises charging the crude oil to a hydroprocessing zone operating under conditions effective to produce a hydroprocessed effluent reduced having a reduced content of contaminants, an increased paraffinicity, reduced Bureau of Mines Correlation Index, and an increased American Petroleum Institute gravity; charging the hydroprocessed effluent to a solvent deasphalting zone with an effective amount of solvent to produce a deasphalted and demetalized oil stream and a bottom asphalt phase; thermally cracking the deasphalted and demetalized oil stream in the presence of steam to produce a mixed product stream; separating the mixed product stream; purifying hydrogen recovered from the mixed product stream and recycling it to the hydroprocessing zone; recovering olefins and aromatics from the separated mixed product stream; and recovering pyrolysis fuel oil from the separated mixed product stream.

Description

RELATED APPLICATIONS[0001]This application claims the benefit of U.S. Provisional Patent Application No. 61 / 591,776 filed Jan. 27, 2012, the disclosure of which is hereby incorporated by reference in its entirety.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates to an integrated hydrotreating, solvent deasphalting and steam pyrolysis process for direct processing of a crude oil to produce petrochemicals such as olefins and aromatics.[0004]2. Description of Related Art[0005]The lower olefins (i.e., ethylene, propylene, butylene and butadiene) and aromatics (i.e., benzene, toluene and xylene) are basic intermediates which are widely used in the petrochemical and chemical industries. Thermal cracking, or steam pyrolysis, is a major type of process for forming these materials, typically in the presence of steam, and in the absence of oxygen. Feedstocks for steam pyrolysis can include petroleum gases and distillates such as naphtha, kerosene an...

AI Technical Summary

Benefits of technology

The present invention is a system and process that integrates steam pyrolysis, hydrotreating and solvent deasphalting to directly process crude oil to produce petrochemicals like olefins and aromatics. The process involves charging crude oil to a hydroprocessing zone to produce a reduced content of contaminants, higher paraffinicity, lower Bureau of Mines Correlation Index, and higher American Petroleum Institute gravity. The hydroprocessed effluent is then sent to a solvent deasphalting zone to produce a deasphalted and demetalized oil stream, which is then thermally cracked in the presence of steam to produce a mixed product stream. The mixed product stream is then separated and purified to recover hydrogen and olefins. The recovered hydrogen is recycled back to the hydroprocessing zone while the separated mixed product stream is used to recover pyrolysis fuel oil. The integrated process provides a more efficient way to produce valuable chemicals from crude oil.

Problems solved by technology

The availability of these feedstocks is usually limited and requires costly and energy-intensive process steps in a crude oil refinery.

A major drawback in conventional heavy hydrocarbon pyrolysis operations is coke formation.

In a comparative example without the addition of molten salt, the steam cracking reactor became clogged and inoperable after just 5 hours because of the formation of coke in the reactor.

While the steam pyrolysis process is well developed and suitable for its intended purposes, the choice of feedstocks has been very limited.

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