Lubricant Base Stock Production via Low Severity Deasphalting
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Solution Overview
Problem
Conventional methods for producing lubricant base stocks from deasphalted oils result in low yields and haze formation over time, limiting the production of high-quality lubricant base stocks, especially when using low severity deasphalting processes.
Innovation Solution
The use of low severity deasphalting followed by a combination of catalytic processing, hydrotreatment, and solvent dewaxing to produce Group I and Group II lubricant base stocks, which includes hydroprocessing and fractionation to separate boiling ranges, and subsequent solvent dewaxing to reduce haze formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If severe propane deasphalting is used to produce suitable feed for lubricant base stock, then the quality of deasphalted oil is improved, but the yield decreases to only about 30 wt%
Solution Approach 1:
The patent changes the operating parameters of the deasphalting process from severe conditions to low severity conditions, specifically adjusting the solvent-to-feed ratio, temperature, and pressure to achieve a yield of at least 50 wt% while maintaining adequate feed quality for subsequent catalytic processing
Solution Approach 2:
The patent introduces catalytic processing as an intermediary step between deasphalting and lubricant base stock production. This intermediate catalytic treatment modifies the deasphalted oil to enable it to serve as suitable feedstock even when produced under low severity conditions, thus bridging the gap between high yield and adequate quality
2Device complexity
If conventional deasphalting methods are used, then the process is simple, but haze formation occurs over time in the produced lubricant base stock
Solution Approach 1:
The patent applies preliminary catalytic processing and hydrotreatment to the deasphalted oil before final lubricant base stock production. These preliminary actions remove impurities and stabilize the oil composition in advance, preventing haze formation during storage and use without requiring complex post-processing steps
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 approach increases the yield of deasphalted oil to at least 50 wt% and produces lubricant base stocks with reduced haze formation, achieving desired compositional properties such as high viscosity index and saturates content, while maintaining stability over extended periods.
Implementation Method 1
deasphalted oils produced by low severity deasphalting of resid fractions
Implementation Method 2
hydrotreating, followed by solvent extraction to perform sufficient VI uplift to form lubricating oils
Implementation Method 3
subsequent solvent dewaxing to reduce haze formation
Implementation Method 4
The hydroprocessed stream is then fractionated to form a heavier fraction and a lighter fraction at a cut point between 1150°F - 1300°F
Data Source
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AI summary
Compositions are provided for lubricant base stocks produced from feeds such as vacuum resid or other 510°C+ feeds. A feed can be deasphalted and then catalytically and/or solvent processed to form lubricant base stocks, including bright stocks that are resistant to haze formation.