Hydroprocessing Catalyst Pore Structure for Heavy Feed Demetallization
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Solution Overview
Problem
Existing hydroprocessing catalysts struggle with inadequate sulfur and metals removal, particularly nickel, in processing heavier crudes, leading to complications in downstream processing and catalyst degradation.
Innovation Solution
A hydroprocessing catalyst with a three-metal formulation of molybdenum, cobalt (or rhodium/iridium), and nickel (or palladium/platinum) on a peptized alumina carrier, featuring a specific pore size distribution for enhanced sulfur and metals removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional hydroprocessing catalysts are used, then basic sulfur and metals removal is achieved, but removal efficiency is insufficient particularly for nickel in heavy feeds
Solution Approach 1:
The patent changes the chemical composition parameters by introducing a three-metal formulation (molybdenum, cobalt/nickel, and zinc oxide) with specific weight ratios (Mo: 4-12 wt%, Co/Ni: 1-3 wt%, ZnO: 5-15 wt%). This compositional parameter change enhances the catalyst's demetallization activity and sulfur removal efficiency, particularly for nickel removal in heavy feeds, resolving the contradiction between basic removal capability and removal efficiency.
Solution Approach 2:
The patent creates a composite catalyst material combining three different metal components (molybdenum, cobalt/nickel, and zinc oxide) on an alumina support. This composite structure synergistically enhances the catalyst's performance: molybdenum provides hydrodesulfurization activity, cobalt/nickel enhances demetallization, and zinc oxide prevents pore blockage. The composite material approach resolves the contradiction by achieving both high removal efficiency and sustained productivity.
2Productivity
If catalyst activity is increased for sulfur and metals removal, then removal efficiency improves, but catalyst deactivation and pore blockage occur faster
Solution Approach 1:
The patent introduces zinc oxide as an intermediary component that mediates between the high-activity metal sites and the alumina support structure. Zinc oxide acts as a structural promoter that prevents sintering of the active metal particles and blocks pore closure, thereby maintaining catalyst porosity and activity retention over time. This intermediary role resolves the contradiction between high initial activity and long-term durability.
Solution Approach 2:
The patent incorporates zinc oxide beforehand as a protective component that cushions against deactivation mechanisms. The zinc oxide preemptively prevents pore blockage by maintaining pore structure integrity and protects metal particles from sintering during high-temperature operation. This prior cushioning effect ensures the catalyst maintains its activity over extended periods, resolving the contradiction between high productivity and duration of action.
3Reliability
If conventional two-metal catalysts are used, then manufacturing is simpler, but sulfur and metals removal activity is insufficient
Solution Approach 1:
The patent implements multi-functionality by designing a three-metal catalyst where each component performs multiple roles: molybdenum provides hydrodesulfurization and hydrodemetallization activity, cobalt/nickel enhances demetallization specifically, and zinc oxide provides structural support and prevents deactivation. This multi-functional design achieves superior sulfur and metals removal capability while the components can be impregnated using standard procedures, managing the complexity through functional integration rather than procedural complexity.
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 demonstrates superior sulfur and metals removal capabilities, especially for nickel, maintaining high activity and preventing pore blockage under wide-ranging reaction conditions.
Implementation Method 1
a catalyst comprising a carrier and a metals component impregnated in the carrier... superior sulfur and metals removal capabilities
Implementation Method 2
a metals component impregnated in the carrier... comprising alumina
Data Source
AI summary
A catalyst comprising a carrier and a metals component impregnated in the carrier, the carrier comprising alumina; and the metals component comprising a first metals fraction and a second metals fraction, the first metals fraction comprising at least one metal selected from chromium, molybdenum, or tungsten, and the second metals fraction comprising at least two metals selected from cobalt, rhodium, iridium, nickel, palladium, or platinum, wherein the catalyst has a first pore volume of 0.28 to 0.45 mL/g for pores having a pore diameter of 12 nm to less than 16 nm, and a second pore volume of 0.15 to 0.28 mL/g for pores of 2.0 nm to less than 12.0 nm.