Hydroprocessing Catalyst Rejuvenation Without Post-Calcination
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Solution Overview
Problem
Conventional hydrotreating and hydrocracking catalysts become deactivated due to coke and sulfur-based compounds, leading to reduced activity and necessitating replacement, with regenerated catalysts being less active than fresh ones, and existing rejuvenation methods do not fully restore their performance.
Innovation Solution
A process involving regeneration at 300-550°C, followed by impregnation with specific amounts of group VIB and VIII metal precursors and an organic compound, then drying without calcination, to rejuvenate the catalyst, optimizing metal distribution and activity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If catalysts are regenerated by gentle calcination to remove coke and sulfur accumulation, then catalyst reuse is achieved and waste is reduced, but catalytic activity decreases compared to fresh catalysts
Solution Approach 1:
The patent changes the chemical parameters of the catalyst by introducing metal precursors (such as molybdenum, nickel, or cobalt compounds) and organic compounds during the rejuvenation process. This transforms the catalyst composition to restore activity, with metal precursor content controlled at 0.1-5% by weight and organic compound content at 1-10% by weight relative to catalyst weight
Solution Approach 2:
The patent creates a composite rejuvenation treatment combining metal precursors and organic compounds applied to the regenerated catalyst. This composite approach addresses both the structural restoration needed after calcination and the activity enhancement required for optimal performance
2Productivity
If additional metal precursors and organic compounds are introduced during rejuvenation to restore activity, then catalytic performance improves, but process complexity increases
Solution Approach 1:
The patent applies preliminary action by introducing metal precursors and organic compounds to the regenerated catalyst before it is fully deactivated. The rejuvenation treatment is applied proactively during the catalyst lifecycle, allowing restoration of activity without requiring complete catalyst replacement
Solution Approach 2:
The patent controls specific parameters to manage complexity: metal precursor content at 0.1-5% by weight, organic compound content at 1-10% by weight, and molar ratio of organic compound to metals between 0.1-10. These controlled parameter ranges standardize the rejuvenation process
3Productivity
If frequent catalyst replacement is performed to maintain high activity, then production efficiency is maintained, but cost increases and waste generation increases
Solution Approach 1:
The patent applies discarding and recovering by extending catalyst life through rejuvenation treatment. Instead of discarding deactivated catalysts, the process recovers their utility by removing coke and sulfur accumulation via gentle calcination and then restoring activity through metal precursor and organic compound introduction, allowing multiple reuse cycles
Solution Approach 2:
The patent inverts the disposable approach by making the catalyst durable through rejuvenation. Rather than treating catalysts as single-use components, the process enables repeated regeneration and reuse, reducing the frequency of replacement and associated waste
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 rejuvenated catalyst achieves catalytic performance close to that of a fresh catalyst, particularly in reducing sulfur and nitrogen content, with improved activity and efficiency.
Implementation Method 1
said regenerated catalyst is then brought into contact with an impregnation solution consisting of a mixture of water, at least one precursor of a group VIB metal, at least one precursor of a group VIII metal and at least one organic compound
Implementation Method 2
a drying step is then carried out at a temperature of less than 200° C., without subsequently calcining it
Data Source
AI summary
The invention relates to a process for rejuvenating an at least partially spent hydrotreating and/or hydrocracking catalyst, said catalyst comprising a group VIII metal, a group VIB metal and an oxide support, said process comprising the following steps:a) the catalyst is regenerated,b) said regenerated catalyst is then brought into contact with an impregnation solution consisting of a mixture of water, at least one precursor of a group VIB metal, at least one precursor of a group VIII metal and at least one organic compound, the amount of organic compound introduced into the regenerated catalyst being optimized with respect to the metals already present in the regenerated catalyst and with respect to the amount of metals introduced via the impregnation solution,c) a drying step is then carried out without subsequently calcining it.