Hydroprocessing Catalytic Slurry Oil to Reduce Coke Formation
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Solution Overview
Problem
Conventional FCC processes struggle to effectively process catalytic slurry oil, a high-boiling fraction from FCC units, due to its high aromatic content and asphaltenes, which leads to coke formation and incompatibility issues during hydroprocessing, limiting the conversion of valuable products and resulting in low-value fuel oil.
Innovation Solution
Hydroprocessing of catalytic slurry oil under fixed bed conditions to convert asphaltenes substantially and minimize coke formation, followed by FCC processing at low temperature and high conversion conditions to produce high-value naphtha and distillate boiling range fuels with reduced sulfur content.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional FCC processes are used to process catalytic slurry oil, then the process is simple and well-established, but coke formation occurs and conversion is limited due to high aromatic content and asphaltenes
Solution Approach 1:
The patent applies preliminary hydroprocessing treatment to the catalytic slurry oil before FCC processing. This preliminary action removes asphaltenes and reduces aromatic content through hydroconversion reactions, preventing coke formation during subsequent FCC operations while enabling higher conversion rates of valuable products
Solution Approach 2:
The patent converts the harmful high aromatic content and asphaltenes in catalytic slurry oil into beneficial effects by using hydroprocessing to transform these problematic components. The hydroconversion process converts aromatics to more saturated compounds and removes asphaltenes, turning the originally harmful composition into a feedstock suitable for high-efficiency FCC processing
2Productivity
If hydroprocessing is applied to convert asphaltenes, then conversion efficiency improves, but process complexity increases due to additional processing steps
Solution Approach 1:
The patent segments the overall processing into two distinct stages: (1) hydroprocessing stage for asphaltene conversion and aromatic reduction, and (2) FCC stage for high-value product formation. This segmentation allows each process to be optimized independently while maintaining overall efficiency and managing complexity through modular design
3Productivity
If FCC processing operates at conventional conditions, then operating conditions are stable and well-controlled, but product value is limited due to low conversion of valuable fractions
Solution Approach 1:
The patent changes key operating parameters of the FCC process by feeding hydroprocessed material with reduced asphaltene and aromatic content. This parameter change in feed composition enables operation at conditions that maximize conversion to high-value naphtha and distillate products while maintaining operational stability through the improved feed quality
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 allows for the conversion of catalytic slurry oil into low sulfur diesel and naphtha fuels with increased product volume, minimizing coke formation and achieving high conversion rates, thereby overcoming the limitations of conventional FCC processing.
Implementation Method 1
Hydroprocessing of catalytic slurry oil under fixed bed conditions to convert asphaltenes substantially and minimize coke formation
Implementation Method 2
FCC processing at low temperature and high conversion conditions to produce high-value naphtha and distillate boiling range fuels
Data Source
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AI summary
Systems and methods are provided for upgrading catalytic slurry oil to form naphtha boiling range and/or distillate boiling range fuel products. It has been unexpectedly discovered that catalytic slurry oil can be separately hydroprocessed under fixed bed conditions to achieve substantial conversion of asphaltenes within the slurry oil (such as substantially complete conversion) while reducing or minimizing the amount of coke formation on the hydroprocessing catalyst. After hydroprocessing, the hydroprocessed effluent can be processed under fluid catalytic cracking conditions to form various products, including distillate boiling range fuels and/or naphtha boiling range fuels. Another portion of the effluent can be suitable for use as a low sulfur fuel oil, such as a fuel oil having a sulfur content of 0.1 wt% or less.