Slurry Hydroconversion Catalyst with Polymodal Alumina
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Solution Overview
Problem
Existing slurry processes for hydroconversion of heavy hydrocarbon fractions face challenges in achieving effective deasphalting and demetallization while maintaining catalyst stability, as conventional catalysts and substrates can lead to coking and porosity blocking.
Innovation Solution
A process involving the use of a dispersed sulfurated catalyst formed by injecting a metal catalytic precursor in the absence of an oxide substrate, combined with alumina oxide particles having a polymodal texture, which are specifically prepared through a series of steps to enhance mechanical strength and porosity, preventing acidity-induced coking and porosity blocking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional catalysts and substrates are used in slurry hydroconversion processes, then catalytic activity for hydrorefining is achieved, but coking and porosity blocking occur leading to reduced catalyst stability
Solution Approach 1:
The invention changes the chemical composition parameters of the catalyst system by using a metal precursor (such as molybdenum or cobalt) combined with an organic acid (such as oxalic acid), replacing conventional catalyst formulations. This parameter change prevents the formation of coke and maintains porosity, thereby improving catalyst stability while maintaining hydrorefining activity
Solution Approach 2:
The invention creates a composite catalytic system by combining metal precursors with organic acid components in specific ratios. This composite approach forms a dispersed catalytic phase that maintains structural integrity and porosity during operation, preventing the coking issues associated with conventional single-component catalysts
2Productivity
If dispersed catalyst is used for hydroconversion, then catalytic activity is improved, but deasphalting and demetallization performance is insufficient
Solution Approach 1:
The invention optimizes the compositional parameters of the dispersed catalyst by incorporating specific metal precursors (molybdenum, cobalt) and organic acids (oxalic acid) in controlled amounts. This parameter optimization enables the catalyst to simultaneously achieve high hydroconversion productivity and effective deasphalting/demetallization performance through enhanced catalytic selectivity
3Stability of the object's composition
If oxide substrate is present during catalyst formation, then catalyst structure is stabilized, but acidity-induced coking and porosity blocking occur
Solution Approach 1:
The invention extracts or removes the oxide substrate component from the catalyst formation process, using only metal precursors and organic acids to form the active catalytic phase. This extraction eliminates the source of acidity that causes coking and porosity blocking, while the metal-organic acid complex itself provides sufficient structural stability for the catalyst
Solution Approach 2:
The invention replaces the conventional oxide substrate with a short-living organic acid component that decomposes to form the active catalyst while avoiding long-term stability issues. The organic acid (oxalic acid) serves as a temporary structural organizer during catalyst formation but does not persist to cause acidity-induced coking
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 improves deasphalting and demetallization performance and maintains catalyst stability by preventing acidity-induced coking and porosity blocking, allowing for efficient hydroconversion of heavy hydrocarbon feedstocks without substrate-induced accessibility issues.
Implementation Method 1
thermal treatment at a temperature of 400° C. or below, in the presence of H2S so as to form the dispersed sulphur-containing catalyst
Implementation Method 2
thermal treatment at a temperature of 400° C. or below, in the presence of H2S so as to form the dispersed sulphur-containing catalyst
Implementation Method 3
said oxide particles having a polymodal porous structure composed of a plurality of juxtaposed agglomerates and each formed from a plurality of acicular platelets
Data Source
AI summary
The invention relates to a process for converting heavy hydrocarbonaceous feedstocks carried out in a slurry reactor in the presence of hydrogen and in the presence of a catalytic composition obtained by:injecting a catalytic precursor of at least one metal of Group VIB and/or Group VIII in at least part of the feedstock to be treated in the absence of an oxide substrate,thermal treatment at a temperature of 400° C. or below, in the presence of H2S so as to form the dispersed sulphur-containing catalyst,bringing said catalyst into contact with particles of alumina oxide free from silica, said oxide particles having a polymodal porous structure composed of a plurality of juxtaposed agglomerates and each formed from a plurality of acicular platelets, the platelets of each agglomerate being oriented radially in relation to one another and relative to the centre of the agglomerate, said particles having an irregular non-spherical shape and being mainly in the form of fragments obtained by crushing with alumina balls,introducing the catalyst composition obtained into the reactor.