Bimodal Porous Mo Catalyst for Hydrodeoxygenation
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Solution Overview
Problem
The existing hydroprocessing technologies face challenges in controlling reaction conditions in the top part of the reactor during the conversion of vegetable and animal oils with hydrogen, leading to rapid temperature increases, hydrogen partial pressure reduction, coke formation, and catalyst deactivation, resulting in high pressure drops and reduced catalyst lifespan.
Innovation Solution
A hydrodeoxygenation process using a supported Mo catalyst with a bimodal porous structure, where the catalyst is impregnated with Mo and has a support made of alumina, silica, or titania, with a macropore volume of at least 2% and a metal content of 0.1-20 wt%, which slows down the reaction rate to prevent coke formation and maintain hydrogen partial pressure, allowing for better temperature control and extended catalyst life.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional hydroprocessing catalysts are used to convert vegetable and animal oils with hydrogen, then conversion of renewable organic material into hydrocarbons is achieved, but rapid temperature increase and hydrogen partial pressure reduction occur leading to coke formation and catalyst deactivation
Solution Approach 1:
The patent employs a support material with a bimodal pore size distribution (containing both small pores <2 nm and large pores >50 nm) to optimize catalyst performance. The large pores facilitate mass transport of bulky triglyceride molecules and prevent coke accumulation, while the small pores provide high surface area for active sites, thereby maintaining high conversion rates without catalyst deactivation
Solution Approach 2:
The patent modifies the physical and chemical parameters of the catalyst support, specifically the pore size distribution, surface area, and acidity. By controlling the pore size bimodality and adjusting the basicity/acidity balance of the support, the reaction conditions are optimized to prevent rapid temperature increases and hydrogen pressure drops, thus avoiding coke formation while maintaining high productivity
2Productivity
If conventional hydroprocessing conditions are applied, then conversion of oils into hydrocarbons occurs, but coke formation leads to high pressure drops and reduced catalyst activity
Solution Approach 1:
The bimodal pore structure with large pores (>50 nm) provides channels for efficient mass transport and prevents coke accumulation by facilitating the removal of heavy intermediates and products. The small pores (<2 nm) provide high surface area for catalytic activity, creating a synergistic effect that maintains high hydrocarbon production while minimizing coke formation
Solution Approach 2:
The patent utilizes the basicity of the support material to promote selective reactions that avoid coke-forming pathways. The basic sites facilitate triglyceride decomposition and fatty acid formation while suppressing polymerization and condensation reactions that lead to coke, thus converting the support's chemical properties into a beneficial anti-coking mechanism
3Productivity
If high metal content catalyst is used to increase conversion rate, then productivity improves, but catalyst cost and susceptibility to deactivation increase
Solution Approach 1:
The patent optimizes the metal content parameter within a specific range (0.1-20 wt%) and combines it with controlled support properties (pore size, surface area, basicity). This parameter optimization achieves high conversion efficiency without requiring excessive metal loading, thereby reducing catalyst complexity and deactivation susceptibility 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
This approach enables efficient conversion of renewable organic materials into diesel-range hydrocarbons with reduced catalyst deactivation and pressure drops, minimizing coke formation and maintaining reactor stability, while achieving high conversion rates and meeting fuel specifications.
Implementation Method 1
a supported hydrodeoxygenation catalyst, wherein the metal component of the hydrodeoxygenation catalyst is Mo only
Implementation Method 2
said support having a bimodal porous structure with pores with a diameter as measured by mercury intrusion porosimetry larger than 50 nm that constitute at least 2 vol% of the total pore volume
Implementation Method 3
reacted with hydrogen at elevated temperature and pressure in a catalytic reactor
Implementation Method 4
hydrodeoxygenation process using a supported Mo catalyst
Data Source
AI summary
The invention relates to a process and hydrodeoxygenation catalyst for producing high-quality diesel and naphtha fuels from a feedstock that contains oxygen containing components derived from renewable organic material in which the hydrodeoxygenation catalyst is a supported Mo catalyst and in which the support has a bimodal porous structure.