Lubricant Feed Hydrotreating Before Extraction to Cut Impurities
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Solution Overview
Problem
Existing lubricant production methods result in high aromatic content products with elevated levels of sulfur, nitrogen, and metals, posing difficulties in certain applications where these impurities are undesirable.
Innovation Solution
A method involving hydrotreating a feedstock under specific conditions to reduce sulfur, nitrogen, and metals, followed by solvent extraction and dewaxing to produce a raffinate and extract with minimized impurities, including catalytic dewaxing using molecular sieves and solvent dewaxing to achieve desired properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If aromatic extraction is performed prior to hydrotreating to produce high aromatic content extract product, then the extract product has increased aromatic content, but the extract product has elevated levels of sulfur, nitrogen, and metals
Solution Approach 1:
The patent applies preliminary hydrotreating action before aromatic extraction. The feedstock is first subjected to hydrotreating under controlled conditions (less than 15% conversion) to remove sulfur, nitrogen, and metals, and then aromatic extraction is performed. This sequence resolves the contradiction by eliminating harmful impurities before they can contaminate the high aromatic content extract product.
Solution Approach 2:
The patent changes the process parameters by controlling hydrotreating conversion to less than 15% (and in some embodiments less than 10%), maintaining specific temperature (300°C to 450°C) and pressure (3.4 MPa to 8.2 MPa) ranges. These parameter changes ensure sufficient removal of sulfur, nitrogen, and metals while preserving aromatic content for subsequent extraction, thus resolving the contradiction between aromatic enrichment and impurity removal.
2Object-generated harmful factors
If conventional hydrotreating is used to reduce sulfur, nitrogen, and metals, then impurity levels are reduced, but hydrogen consumption increases
Solution Approach 1:
The patent applies partial action by limiting hydrotreating conversion to less than 15% (and in some embodiments less than 10%). This partial treatment is sufficient to reduce sulfur, nitrogen, and metals to acceptable levels for the extract product while avoiding excessive hydrogen consumption that would occur with complete conversion. The controlled partial treatment optimizes the balance between impurity removal and hydrogen usage.
Solution Approach 2:
The patent optimizes hydrotreating parameters including temperature (300°C to 450°C), pressure (3.4 MPa to 8.2 MPa), and LHSV (0.1 to 5.0 hr-1) to achieve efficient impurity removal at reduced hydrogen consumption. These parameter changes enable the process to remove sulfur, nitrogen, and metals effectively while maintaining lower hydrogen requirements compared to conventional high-conversion hydrotreating.
3Object-generated harmful factors
If high conversion hydrotreating is used to maximize impurity removal, then sulfur, nitrogen, and metals are minimized, but feed conversion exceeds 15% reducing process efficiency
Solution Approach 1:
The patent deliberately applies partial action by limiting hydrotreating conversion to less than 15% (and in some embodiments less than 10%). This partial conversion is sufficient to remove impurities to levels suitable for the intended application, while avoiding excessive conversion that would reduce feed efficiency and overall process productivity. The approach optimizes the trade-off between impurity removal and feed utilization.
Solution Approach 2:
The patent performs preliminary hydrotreating at controlled low conversion levels before aromatic extraction. This preliminary action removes the necessary amount of impurities to enable effective extraction without over-processing the feed, thereby maintaining high feed conversion efficiency and productivity while achieving the required purity levels for the extract product.
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 produces dewaxed raffinate and extract products with reduced sulfur, nitrogen, and metals, suitable for high-quality lubricant base oils and other applications, while minimizing hydrogen consumption.
Implementation Method 1
The hydrotreating conditions comprise exposing the feedstock to a hydrotreating catalyst at a pressure of 3.4 MPa to 8.2 MPa (500 psig to 1200 psig), a temperature of 300°C to 450°C
Implementation Method 2
hydrotreating a feedstock under specific conditions to reduce sulfur, nitrogen, and metals
Implementation Method 3
A solvent extraction is performed on the hydrotreated effluent fraction to form at least a raffinate product and an extract product
Implementation Method 4
catalytic dewaxing using molecular sieves
Data Source
Figure 1
AI summary
Systems and methods are provided for producing upgraded raffinate and extract products from lubricant boiling range feeds and/or other feeds having a boiling range of 400°F (204°C) to 1500°F (816°C) or more. The upgraded raffinate and/or extract products can have a reduced or minimized concentration of sulfur, nitrogen, metals, or a combination thereof. The reduced or minimized concentration of sulfur, nitrogen, and/or metals can be achieved by hydrotreating a suitable feed under hydrotreatment conditions corresponding to relatively low levels of feed conversion. Optionally, the feed can also dewaxed, such as by catalytic dewaxing or by solvent dewaxing. Because excessive aromatic saturation is not desired, the pressure for hydrotreatment (and optional dewaxing) can be 500 psig (∼3.4 MPa) to 1200 psig (∼8.2 MPa).