High Viscosity Group I Base Stock via Radical Coupling

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Solution Overview

Problem

Conventional methods for producing high viscosity lubricant base stocks, such as solvent processing and catalytic processing, face challenges in reducing sulfur and nitrogen content while maintaining viscosity, with catalytic processing limiting viscosities to around 10 cSt at 100°C and being costly for specialty polymeric materials.

Innovation Solution

A method involving radical coupling using a peroxide catalyst on a feedstock with specific properties, followed by fractionation, to produce a base stock with increased viscosity and desirable molecular weights, sulfur content, and aromatics content, achieving viscosities greater than 35 cSt at 100°C and 600 cSt at 40°C.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If solvent processing is used to produce high viscosity base stocks, then viscosity is improved, but sulfur and nitrogen content reduction is insufficient

Engineering Contradiction:
ImproveviscosityVSAvoidsulfur and nitrogen content
Core Design Contradiction:
TemperatureVSObject-generated harmful factors

Solution Approach 1:

The patent combines solvent processing with selective hydroprocessing to integrate the viscosity-preserving benefits of solvent processing with the heteroatom removal capabilities of hydroprocessing, creating a hybrid process that achieves both high viscosity and low sulfur/nitrogen content

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent modifies hydroprocessing parameters (catalyst selection, temperature, pressure, residence time) to reduce sulfur and nitrogen content while minimizing viscosity loss, using optimized processing conditions to achieve selective removal of heteroatoms without excessive cracking

Inventive Principle:
Principle #35Parameter changes

2Object-generated harmful factors

If hydrotreating and hydrocracking processes are used for heteroatom removal, then sulfur and nitrogen content is reduced, but viscosity is significantly reduced

Engineering Contradiction:
Improvesulfur and nitrogen contentVSAvoidviscosity
Core Design Contradiction:
Object-generated harmful factorsVSTemperature

Solution Approach 1:

The patent applies partial hydroprocessing rather than severe hydrocracking, using controlled treatment levels that remove sufficient heteroatoms while preserving the bulk of the viscosity, avoiding excessive cracking that would lead to unacceptable viscosity loss

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The patent optimizes hydroprocessing parameters including using milder catalysts, lower temperatures, reduced pressures, and shorter residence times to achieve heteroatom removal with minimal viscosity impact

Inventive Principle:
Principle #35Parameter changes

3Productivity

If catalytic processing is used to produce base stocks, then production efficiency is improved, but maximum viscosity is limited to about 10 cSt at 100°C

Engineering Contradiction:
Improveproduction efficiencyVSAvoidviscosity
Core Design Contradiction:
ProductivityVSTemperature

Solution Approach 1:

The patent merges catalytic processing with solvent processing steps, using catalysis for efficient feedstock conversion followed by solvent processing to concentrate and isolate the high viscosity components that would otherwise be limited by catalytic cracking

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent segments the processing into distinct stages: catalytic conversion followed by solvent extraction and fractionation, allowing each process to operate in its optimal range and preserve the high viscosity components through selective separation

Inventive Principle:
Principle #1Segmentation

4Temperature

If specialty polymeric materials are used to achieve high viscosity, then viscosity is improved, but production cost increases

Engineering Contradiction:
ImproveviscosityVSAvoidproduction cost
Core Design Contradiction:
TemperatureVSEase of manufacture

Solution Approach 1:

The patent uses conventional, readily available feedstocks and standard processing equipment rather than expensive specialty polymers, achieving high viscosity through physical processing of common materials rather than costly chemical synthesis of specialized compounds

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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

The method effectively produces high viscosity base stocks with improved properties, including a viscosity index of 50 to 150, polydispersity of at least 1.4, and a pour point of 0°C or less, while minimizing viscosity loss due to hydroprocessing, and retaining desirable characteristics of conventional low molecular weight Group I base stocks.

Implementation Method 1

radical coupling using a peroxide catalyst of a feedstock having a viscosity index of 50 to 120, a kinematic viscosity at 100°C of 12 cSt or less

Methodology Applied
Scientific EffectRadical coupling:

Implementation Method 2

radical coupling using a peroxide catalyst under effective coupling conditions to form a coupled effluent

Methodology Applied
Scientific EffectPeroxide catalysis: Catalysis

Implementation Method 3

fractionating at least a portion of the coupled effluent to form at least a first product fraction

Methodology Applied
Scientific EffectFractionation: Fractionation

Data Source

PatentEP3374473B1High viscosity base stock compositions
Publication Date: 2024.05.01 EXXONMOBIL TECHNOLOGY & ENGINEERING CO
  • EP3374473B1 patent drawingFigure 1~2
  • EP3374473B1 patent drawingFigure 3~4
  • EP3374473B1 patent drawingFigure 5~6

AI summary

Methods are provided for producing Group I base stocks having high viscosity and also having one or more properties indicative of a high quality base stock. The resulting Group I base stocks can have a viscosity at 100°C and/or a viscosity at 40°C that is greater than the corresponding viscosity for a conventional Group I bright stock formed by solvent processing. Additionally, the resulting Group I base stocks can have one or more properties that are indicative of a high quality base stock.