Hydroprocessing Catalyst Distribution for Coke Reduction
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Solution Overview
Problem
Current hydroprocessing systems face challenges in efficiently upgrading heavy oil feeds due to issues like coke formation, reduced catalyst activity, and difficulty in processing feed streams, particularly in subsequent contacting zones, which affects conversion rates and product quality.
Innovation Solution
The process involves a plurality of contacting and separation zones where a portion of the heavy oil feed and fresh catalyst are diverted to zones other than the first, allowing for a more uniform catalyst concentration and liquid dilution, reducing coke formation and improving catalytic activity, with a focus on hydrocracking conditions and hydrogen addition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If heavy oil feedstock is fed to the first contacting zone in conventional hydroprocessing systems, then the heavy oil can be processed through sequential conversion in multiple reactors, but coke formation increases and catalyst activity decreases in subsequent contacting zones
Solution Approach 1:
The invention segments the heavy oil feedstock distribution across multiple contacting zones rather than concentrating it in the first zone. Specifically, a portion of the heavy oil feed is diverted to the second and/or third contacting zones, creating a segmented feed pattern that distributes the conversion load and reduces coke formation in any single zone while maintaining overall productivity.
Solution Approach 2:
The invention applies local quality by creating different feed compositions in different contacting zones. The first zone receives a different proportion of heavy oil feed compared to subsequent zones, allowing each zone to operate under optimized conditions that balance conversion efficiency with catalyst protection and coke reduction.
2Reliability
If all fresh catalyst is fed to the first contacting zone, then the initial conversion activity is high, but catalyst concentration becomes non-uniform across subsequent zones
Solution Approach 1:
The invention segments the fresh catalyst feed distribution across multiple contacting zones. Instead of feeding all fresh catalyst to the first zone, portions are diverted to subsequent zones, creating a segmented catalyst distribution pattern that ensures uniform catalyst concentration and sustained activity throughout the reactor series.
Solution Approach 2:
The invention applies local quality by providing different catalyst concentrations to different contacting zones based on their specific needs. Subsequent zones receive fresh catalyst feeds tailored to their conversion requirements, ensuring each zone maintains optimal catalyst activity and concentration uniformity.
3Productivity
If heavy oil feedstock is concentrated in the first contacting zone, then initial conversion is efficient, but liquid dilution is insufficient in subsequent zones affecting product quality
Solution Approach 1:
The invention segments the heavy oil feed distribution to provide liquid dilution in subsequent contacting zones. By diverting portions of the heavy oil feed to the second and/or third zones, the system creates liquid dilution effects that improve product quality while maintaining overall conversion efficiency through the segmented feed pattern.
Solution Approach 2:
The invention applies local quality by creating different liquid dilution conditions in different contacting zones. Subsequent zones receive heavy oil feed portions that provide the necessary liquid dilution for optimal product quality, while the first zone maintains conditions optimized for initial conversion efficiency.
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 enhances the overall cracking efficiency, reduces coke formation, and improves the quality of upgraded products by maintaining higher catalytic activity and reducing impurities like nickel and MCR, while maintaining conversion rates and system stability.
Implementation Method 1
combining a hydrogen containing gas feed, a portion of the heavy oil feedstock, and a slurry catalyst in a first contacting zone under hydrocracking conditions to convert at least a portion of the heavy oil feedstock to upgraded products
Implementation Method 2
combining a hydrogen containing gas feed, a portion of the heavy oil feedstock, and a slurry catalyst in a first contacting zone under hydrocracking conditions
Data Source
AI summary
Systems and methods for hydroprocessing a heavy oil feedstock, the system employs a plurality of contacting zones and separation zones with at least some of the heavy oil feedstock being supplied to at least a contacting zone other than the first contacting zone. The contacting zones operate under hydrocracking conditions, employing a slurry catalyst for upgrading the heavy oil feedstock, forming upgraded products of lower boiling boiling hydrocarbons. In the separation zones, upgraded products are removed overhead and optionally, further treated in an in-line hydrotreater. At least a portion of the non-volatile fractions recovered from at least one of the separation zones is recycled back to the first contacting zone in the system.