Multi-Metallic Catalyst Macropore Distribution for Heavy Oil Hydroconversion
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Solution Overview
Problem
The petroleum industry faces challenges in upgrading heavy crudes and lower grade hydrocarbons due to the need for catalysts with optimal porosity and surface area for efficient hydroconversion, as highly porous catalysts often lack sufficient surface area and catalytic activity.
Innovation Solution
A bulk multi-metallic catalyst is developed by sulfiding a catalyst precursor comprising Group VIB and promoter metal compounds, with a monomodal pore size distribution of primarily macropores and a total pore volume of at least 0.08 g/cc, optimized through processes involving precipitation, chelation, and non-agglomerative drying to enhance porosity and surface area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of stationary object
If the catalyst is made highly porous to facilitate efficient through flow and reduce mass transfer resistance, then the pore volume increases, but the surface area decreases leading to low catalytic activity
Solution Approach 1:
The invention changes the pore size distribution parameter from a typical bimodal or multimodal distribution to an essentially monomodal distribution where at least 95% of pores are macropores. This parameter change allows the catalyst to achieve both high pore volume (at least 0.08 g/cc) and adequate surface area, resolving the contradiction between porosity and surface area by optimizing the pore size characteristics rather than simply increasing overall porosity.
2Productivity
If the catalyst has high porosity to facilitate reactant access, then mass transfer resistance decreases, but the catalyst volume shrinks and mechanical strength decreases
Solution Approach 1:
The invention optimizes the pore size distribution parameter to be essentially monomodal with at least 95% macropores, which provides sufficient pore volume (at least 0.08 g/cc) for good mass transfer while maintaining catalyst structural integrity. This specific pore structure configuration allows the catalyst to achieve both high productivity through efficient mass transfer and adequate mechanical strength to resist volume shrinkage during operation.
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 high yield conversions with low volume shrinkage and improved mechanical strength, effectively handling heavy oil feeds by overcoming diffusion limitations and maintaining high catalytic activity in hydroprocessing operations.
Implementation Method 1
a bulk multi-metallic catalyst prepared by sulfiding a catalyst precursor comprising at least a Group VIB metal compound
Implementation Method 2
The upgrading or refining of these feedstocks is accomplished by treating the feedstocks with hydrogen in the presence of catalysts to effect conversion of at least a portion of the feeds to lower molecular weight hydrocarbons
Implementation Method 3
it is desirable to employ catalyst having sufficient open volume (porosity) for low mass transfer resistance and facilitate efficient through flow of reactors
Data Source
AI summary
A method for preparing a bulk multi-metallic suitable for hydrotreating heavy oil feeds is provided. In the process of preparing the catalyst precursor which is subsequently sulfided to form the bulk catalyst, non-agglomerative drying is employed to keep the catalyst precursor from aggregating/clumping, resulting in a catalyst precursor with optimum porosity with at least 90% of the pores being macropores, and having a total pore volume of at least 0.08 g/cc.