Process and Apparatus for Integrated Heavy Oil Upgrading

Abstract

A process and apparatus is disclosed for converting heavy hydrocarbon feed into lighter hydrocarbon products. The heavy hydrocarbon feed is slurried with a particulate solid material to form a heavy hydrocarbon slurry and hydrocracked to produce vacuum gas oil (VGO). A light portion of the VGO may be hydrotreated and subjected to fluid catalytic cracking to produce fuels such as gasoline. A heavy portion of the VGO may be recycled to the slurry hydrocracking reactor. FCC slurry oil may be recycled to the slurry for hydrocracking.

Description

BACKGROUND OF THE INVENTION[0001]This invention relates to a process and apparatus for the treatment of crude oils and, more particularly, to the hydroconversion of heavy hydrocarbons in the presence of additives and catalysts to provide useable products and further prepare feedstock for refining in a fluid catalytic cracking (FCC) unit.[0002]Hydroconversion processes for the conversion of heavy hydrocarbon oils to light and intermediate naphthas of good quality and for reforming feedstocks, fuel oil and gas oil are well known. These heavy hydrocarbon oils can be such materials as petroleum crude oil, atmospheric tower bottoms products, vacuum tower bottoms products, heavy cycle oils, shale oils, coal derived liquids, crude oil residuum, topped crude oils and the heavy bituminous oils extracted from oil sands. Of particular interest are the oils extracted from oil sands and which contain wide boiling range materials from naphthas through kerosene, gas oil, pitch, etc., and which con...

AI Technical Summary

Benefits of technology

[0009]We have found that integration of SHC and hydrotreating with FCC results in improved performance of all three processes. Heavy VGO from the SHC reactor and / or main column bottoms from the FCC unit are combined with the feed to the SHC unit. All lighter products of the SHC are processed in a hydrotreater. The hydrotreater process conditions and catalyst type are chosen so that the light VGO product from the SHC unit is hydrogenated, desulfurized and denitrified to the extent required to maximize or optimize gasoline yield, minimize coke make, and reduce SOx emissions in the FCC unit. The hydrotreated products may be fractionated into boiling ranges which include a VGO. The lighter, lower boiling VGO portion is sent to the FCC unit optionally along with other FCC feedstocks. The FCC main column bottoms may be returned to the SHC to undergo further conversion to VGO, naphtha and distillate.

Problems solved by technology

These heavy hydrocarbon feedstocks may be characterized by low reactivity in visbreaking, high coking tendency, poor conversion in hydrocracking and difficulties in distillation.

They may have, in general, a low ratio of polar aromatics to asphaltenes and poor reactivity in a hydrocracking environment relative to aromatic feedstocks.

However, since this product VGO is hydrogen-deficient and high in sulfur and nitrogen contaminants it must be further hydroprocessed, cracked and / or reformed in order to produce useful transportation fuels.

However, a number of problems must be solved for the FCC unit to perform well with this type of feedstock.

VGO produced in a primary upgrading unit contains high amounts of coke precursors which yield an abnormally high amount of coke in the FCC unit.

The primarily upgraded VGO also contains a low amount of gasoline precursors, so that the yield of FCC gasoline is low while the yield of undesirable FCC main column bottoms is high.

In addition, the high content of nitrogen contaminants in the VGO also suppresses the cracking activity of the FCC catalyst which also lowers gasoline yield.

To meet this specification, refineries typically must dilute the heavy slurry oil with lighter, solids-free products that could otherwise be sold, thus reducing revenues.

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