Two-Stage Hydrocracking for Heavy Lubricating Base Oil Production

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional two-stage hydrocracking processes are unable to effectively process heavy coker gas oil and other disadvantaged streams due to high concentrations of nitrogen, sulfur, and polycyclic aromatics, which shorten catalyst life and limit the production of valuable lubricating base oils.

Innovation Solution

A refined two-stage hydrocracking process that fractionates the product stream into fuels and residuum, with further hydroprocessing and fractionation to produce heavy lubricating base oils, allowing for the removal of deleterious components and extending catalyst life.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional two-stage hydrocracking processes are used to process heavy coker gas oil, then the feedstock can be converted to products, but the high concentrations of nitrogen, sulfur, and polycyclic aromatics shorten catalyst life and limit production

Engineering Contradiction:

Improveproduction of heavy lubricating base oilsVSAvoidcatalyst life

Core Design Contradiction:

ProductivityVSDuration of action of stationary object

Solution Approach 1:

The process divides the conversion into two distinct stages: first stage hydrocracking at severe conditions to remove contaminants (N, S, PNAs) and convert heavy fractions, followed by second stage hydrocracking at mild conditions to produce lubricating base oils. This segmentation allows the severe contaminant removal function and the mild product formation function to be separated, protecting the catalysts from premature deactivation while maintaining productivity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The first stage hydrocracking performs preliminary action by removing deleterious components (nitrogen, sulfur, polycyclic aromatics) before the second stage processing. This preliminary contaminant removal prevents catalyst poisoning in subsequent stages, extending catalyst life while enabling continuous production of heavy lubricating base oils.

Inventive Principle:

Principle #10Preliminary action

2Quantity of substance

If vacuum distillation operates at higher cut-points to yield more HVGO, then the volume of feedstock for processing increases, but the feedstock becomes more disadvantaged with higher particulates, sulfur, and nitrogen species

Engineering Contradiction:

Improvevolume of HVGOVSAvoidparticulates, sulfur, nitrogen species

Core Design Contradiction:

Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

The process changes the operating parameters of the first stage hydrocracker to severe conditions (high temperature, high pressure, high hydrogen partial pressure, low LHSV) specifically tailored to handle disadvantaged feedstocks with high sulfur and nitrogen content. This parameter adjustment enables the unit to process higher cut-point HVGO with more contaminants, converting the quantity increase into viable lubricating base oil production.

Inventive Principle:

Principle #35Parameter changes

3Productivity

If conventional two-stage hydrocracking units process disadvantaged feedstocks, then conversion to products occurs, but the units require closed loop configuration with recycle to extinction which limits feedstock types

Engineering Contradiction:

Improveconversion to productsVSAvoidfeedstock types

Core Design Contradiction:

ProductivityVSAdaptability or versatility

Solution Approach 1:

The process segments the conversion function into two stages with different objectives: first stage for contaminant removal and partial conversion, second stage for final product formation. This segmentation allows the system to handle diverse disadvantaged feedstocks (heavy coker gas oils, visbroken gas oils, gas oils from residue hydrocracking) by adjusting operating parameters while maintaining the closed loop configuration, thereby improving feedstock versatility without sacrificing productivity.

Inventive Principle:

Principle #1Segmentation

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This process enables the production of higher quantities of profitable heavy lubricating base oils while maintaining catalyst efficiency, overcoming the limitations of conventional methods by operating at milder conditions and removing harmful impurities.

Implementation Method 1

Hydrocracking is an important refining process used to produce valuable products such as turbine fuel, diesel fuel and lube oil fractions as well as lower boiling hydrocarbonaceous liquids such as naphtha and gasoline, by hydrocracking a hydrocarbon feedstock derived from crude oil.

Methodology Applied

Scientific EffectHydrocracking: Chemical Bonding

Implementation Method 2

The hydrotreated HVGO 7 is then subjected to hydrocracking conditions in a first stage hydrocracker unit 8

Methodology Applied

Scientific EffectHydrotreating: Chemical Bonding

Implementation Method 3

a desalted crude oil feedstock 1 is distilled in an atmospheric crude distillation unit 2. The bottoms or residuum 3 from the atmospheric distillation process is then distilled in a vacuum distillation unit 4.

Methodology Applied

Scientific EffectDistillation: Distillation

Data Source

PatentUS9914887B2Two-stage hydrocracking process for making heavy lubricating base oil from a heavy coker gas oil blended feedstock

Publication Date: 2018.03.13 CHEVRON USA INC

AI summary

The present invention is directed to a refining process for producing heavy lubricating base oils (LBO) from a blended hydrocarbonaceous feedstock containing a heavy coker gas oil, a visbroken gas oil, heavy cycle oil, oils from residue hydrocracking, aromatic extract or any other feedstock normally not conducive to lube oil basestock production, using a two-stage hydrocracking process.