Hydroconversion Catalyst with Low Volumetric Shrinkage
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Solution Overview
Problem
Catalysts used in hydroconversion processes for heavy hydrocarbon feedstocks experience significant volume shrinkage under severe conditions, leading to reduced effectiveness and increased pressure drop, which compromises reactor performance and yield.
Innovation Solution
A stable bulk multi-metallic catalyst with low volume shrinkage is developed, formed from a catalyst precursor comprising Group VIB and promoter metal compounds, with optional ligating agents and diluents, using a method that includes precipitation, liquid removal, and thermal treatment to minimize shrinkage to less than 10% even at high temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional catalysts are used in hydroconversion processes under severe conditions, then catalytic activity is achieved, but significant volume shrinkage occurs leading to reduced effectiveness and increased pressure drop
Solution Approach 1:
The patent applies parameter changes by modifying the physical and chemical properties of the catalyst support through controlled pore formation, density adjustment, and mechanical strength enhancement. The support is designed with specific pore size distributions and density values that remain stable under hydroconversion conditions, preventing the volume shrinkage that plagues conventional catalysts while maintaining catalytic activity.
Solution Approach 2:
The patent employs composite materials by combining catalytically active components with a specially designed porous support structure. The support comprises multiple phases including crystalline and amorphous regions, creating a composite material that provides both mechanical stability to prevent shrinkage and appropriate porosity to maintain catalytic function under severe hydroconversion conditions.
2Productivity
If catalysts undergo volume shrinkage in fixed bed reactors, then catalytic conversion occurs, but unoccupied channels form causing reactant channeling and reduced bed utilization
Solution Approach 1:
The patent applies preliminary action by pre-forming the catalyst support with a stable porous structure and appropriate mechanical strength before introducing the catalytic active phases. The support is prepared in advance with controlled pore architecture and density that resist shrinkage under reaction conditions, ensuring that the catalyst bed maintains its structural integrity and prevents channeling from the outset rather than degrading over time.
3Power
If catalysts are exposed to high reaction temperatures, then hydroconversion activity is enhanced, but pressure drop across the reactor increases due to volumetric shrinkage
Solution Approach 1:
The patent applies parameter changes by optimizing the thermal stability parameters of the catalyst support through controlled pore formation and density adjustment. The support is designed to maintain its physical dimensions and porosity structure at elevated temperatures, preventing the volumetric shrinkage that would otherwise increase pressure drop while allowing the catalytic reactions to proceed at high temperatures with enhanced activity.
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 catalyst exhibits high mechanical strength and improved performance with minimal shrinkage, maintaining high yield conversions and reducing pressure drop across the reactor, thus enhancing hydroconversion process efficiency.
Implementation Method 1
drying the shaped catalyst precursor at a temperature ranging from 50° C. to 200° C. for about 15 minutes to 12 hours
Implementation Method 2
sulfiding the shaped catalyst precursor forming the bulk multi-metallic catalyst
Implementation Method 3
removing at least 50% of liquid from the precipitate forming a filter cake
Implementation Method 4
forming a precipitate comprising at least a promoter metal precursor, at least a Group VIB metal precursor
Data Source
AI summary
A stable catalyst with low volumetric shrinkage and a process for making the stable catalyst with low volumetric shrinkage is disclosed. The catalyst is made by sulfiding a catalyst precursor containing at least a Group VIB metal compound; at least a promoter metal compound selected from Group VIII, Group IIB, Group IIA, Group IVA and combinations thereof, having an oxidation state of either +2 or +4; optionally at least a ligating agent; optionally at least a diluent. In the process of making the catalyst, the catalyst precursor is first shaped then heat treated at a temperature of 50° C. to 200° C. for about 15 minutes to 12 hours, wherein the catalyst precursor still has a low (less than 12%) volumetric shrinkage after exposure to a temperature of at least 100° C. for at least 30 minutes, e.g., in sulfidation or in a hydrotreating reactor.