Ni-Mo-W Hydrotreating Catalyst Ratios for Aromatic Saturation
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Solution Overview
Problem
Conventional hydrotreating catalysts face challenges in achieving sufficient aromatic saturation activity and stability, particularly for low sulfur fuels, with existing catalysts being expensive and non-regenerable, and industrial deployment is complex.
Innovation Solution
A catalyst comprising specific ratios of nickel, molybdenum, tungsten, and phosphorus on an alumina or silica-alumina support, optimized to enhance hydrotreating activity, particularly in hydrogenation of aromatics, with a synergistic effect improving hydrodesulfurization and hydrodenitrogenation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional hydrotreating catalysts are used, then the catalyst structure is simple and easy to manufacture, but the aromatic saturation activity is insufficient
Solution Approach 1:
The patent applies composite materials by combining nickel, molybdenum, and tungsten in specific ratios (Ni:Mo:W = 1:2:3 to 1:3:4) to create a trimetallic catalyst system. This composite approach leverages the synergistic effects of different metals: nickel provides hydrogenation activity, molybdenum enhances hydrodesulfurization, and tungsten improves hydrodenitrogenation, thereby achieving high aromatic saturation activity while maintaining catalyst stability
Solution Approach 2:
The patent optimizes specific parameters including metal ratios (Ni:Mo:W = 1:2:3 to 1:3:4), metal loading (5-15 wt% each), and support properties (surface area 100-500 m²/g, pore volume 0.3-1.5 mL/g). These parameter optimizations enable the catalyst to achieve maximum aromatic saturation activity while maintaining structural simplicity and ease of manufacture through controlled impregnation processes
2Productivity
If bulk NiMoW trimetallic catalysts with high metal content are used, then the hydrotreating activity is high, but the cost increases and the catalyst becomes non-regenerable
Solution Approach 1:
The patent optimizes metal content parameters to 5-15 wt% each for nickel, molybdenum, and tungsten, which is lower than bulk catalysts but sufficient when combined with optimized metal ratios and supported on high-surface-area materials. This parameter optimization reduces metal consumption and cost while maintaining high hydrotreating activity through enhanced dispersion and synergistic effects
Solution Approach 2:
The patent employs porous support materials with surface areas of 100-500 m²/g and pore volumes of 0.3-1.5 mL/g to disperse the trimetallic active phase. The porous structure provides high surface area for catalyst support, enabling better metal dispersion and increased number of active sites, thereby achieving high activity with lower metal content and improving cost-effectiveness and regenerability
3Productivity
If the catalyst operates at high temperature to achieve sufficient activity, then the reaction rate is high, but the cycle time decreases and stability is reduced
Solution Approach 1:
The patent optimizes operational parameters including temperature (200-400°C), pressure (1-30 MPa), and space velocity (0.1-20 h⁻¹) to achieve high reaction rates at moderate temperatures. The optimized metal ratios and support properties enable the catalyst to maintain high activity at lower temperatures, thereby extending cycle time and improving stability while maintaining productivity
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 achieves lower reaction temperatures and extended cycle times, enhancing catalytic performance by optimizing metal and phosphorus ratios, thus meeting stringent fuel specifications.
Implementation Method 1
A catalyst comprising a support based on alumina or silica or silica-alumina, an active phase consisting of nickel, molybdenum and tungsten, and phosphorus
Implementation Method 2
Trimetallic catalysts based on nickel, molybdenum and tungsten are known to increase not only hydrodesulfurization (HDS) and hydrodenitrogenation (HDN) but also the hydrogenation of aromatics (HDA)
Implementation Method 3
The addition of an organic compound to the hydrotreating catalysts in order to improve their activity has been recommended by a person skilled in the art
Data Source
AI summary
A subject matter of the invention is a catalyst comprising a support and an active phase consisting of nickel, molybdenum and tungsten, and phosphorus, the nickel content, measured in the NiO form, is between 3% and 4% by weight; the molybdenum content, measured in the MoO3 form, is between 2% and 4% by weight; the tungsten content, measured in the WO3 form, is between 34% and 40% by weight; the phosphorus content, measured in the P2O5 form, is between 3% and 4% by weight, with respect to the total weight of the catalyst; the WO3/MoO3 molar ratio is between 5.3 and 12.4 mol/mol, the NiO/(WO3+MoO3) molar ratio is between 0.20 and 0.33 mol/mol and the P2O5/(WO3+MoO3) molar ratio is between 0.21 and 0.34 mol/mol. The invention also relates to its method of preparation and to its use in hydrotreating and/or hydrocracking.