Hydrotreating Catalysts via Partial Organic Acid Calcination
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Solution Overview
Problem
Conventional hydrotreating catalysts are insufficient in achieving high reactivity and effectiveness for removing sulfur and nitrogen from hydrocarbon streams, necessitating the development of more advanced catalysts for efficient hydrotreating processes.
Innovation Solution
A method involving the preparation of a catalyst composition by impregnating an inorganic support with a Group VIB metal salt, a Group VIII metal salt, and an organic acid, followed by calcination to achieve a partially oxidized state with a specific carbon-as-carboxyl to total carbon ratio, and subsequent sulfiding to enhance hydrotreating performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional hydrotreating catalysts are used, then the catalyst structure is simple and easy to manufacture, but the reactivity and effectiveness for removing sulfur and nitrogen are insufficient
Solution Approach 1:
The patent applies preliminary action by performing a controlled calcination treatment before sulfiding to partially decompose the organic acid and create carboxyl groups on the catalyst surface. This pre-treatment step modifies the catalyst precursor structure in advance, creating favorable conditions for subsequent sulfiding and enhancing the final catalyst's hydrodesulfurization and hydrodenitrogenation activities without complicating the overall manufacturing process
Solution Approach 2:
The patent employs parameter changes by precisely controlling the calcination temperature, time, and atmosphere to achieve partial decomposition of the organic acid. By adjusting these parameters, the catalyst develops an optimal carbon-as-carboxyl to total carbon ratio, which significantly enhances its reactivity and effectiveness for heteroatom removal while maintaining a straightforward preparation methodology
2Reliability
If the organic acid is completely decomposed during calcination, then the catalyst is fully activated, but the carbon-as-carboxyl to total carbon ratio becomes too low, reducing catalyst activity
Solution Approach 1:
The patent applies partial action by intentionally limiting the calcination process to achieve only partial decomposition of the organic acid rather than complete decomposition. This controlled partial treatment preserves a significant portion of the organic acid, which then converts to carboxyl groups that provide high catalytic activity. The approach of doing 'less than complete' decomposition actually yields superior catalyst performance
Solution Approach 2:
The patent uses parameter changes to control the extent of organic acid decomposition during calcination. By adjusting calcination temperature, time, and atmospheric conditions, the process achieves an optimal balance where sufficient decomposition creates active carboxyl sites while maintaining a high carbon-as-carboxyl to total carbon ratio, thereby maximizing catalyst activity
3Productivity
If conventional sulfiding is performed without prior controlled calcination, then the process is simpler, but the resulting catalyst has lower hydrodesulfurization and hydrodenitrogenation activities
Solution Approach 1:
The patent applies preliminary action by implementing a controlled calcination step before sulfiding to modify the catalyst precursor structure. This pre-treatment creates carboxyl groups and optimizes the surface chemistry, which significantly enhances the subsequent sulfiding effectiveness and the final catalyst's productivity for removing sulfur and nitrogen from hydrocarbon streams
Solution Approach 2:
The patent ensures continuity of useful action by integrating the calcination step seamlessly into the catalyst preparation sequence, where the partial decomposition of organic acid creates favorable conditions that carry through to the sulfiding step and ultimately to the catalyst's performance in hydrotreating operations, maintaining enhanced activity throughout the process
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 resulting catalysts demonstrate improved hydrodesulfurization and hydrodenitrogenation activities, achieving higher desulfurization and denitrogenation levels in hydrocarbon feedstocks, addressing the limitations of conventional catalysts.
Implementation Method 1
impregnating an inorganic catalyst support with an aqueous solution containing (i) a salt of a Group VIB metal, (ii) a salt of a Group VIII metal, and (iii) an organic acid
Implementation Method 2
calcining the dried catalyst precursor in an oxygen-containing atmosphere for a time and temperature sufficient to oxidize some but not all of the organic portion of the metal-organic component
Implementation Method 3
sulfiding the partially oxidized catalyst precursor at sulfiding conditions in the presence of a sulfiding agent, thereby resulting in a sulfided catalyst composition
Data Source
AI summary
This disclosure relates to supported multi-metallic catalysts for use in the hydrotreating of hydrocarbon feeds. The catalysts are prepared from a catalyst precursor comprised of at least one Group VIB metal, at least one Group VIII metal and an organic acid. The catalyst precursor is thermally treated to partially decompose the organic acid, then sulfided. The catalysts have a high carbon-as-carboxyl to total carbon ratio (Ccarboxy/Ctotal) as a result of a unique post-metal calcination method employed during the manufacture of the catalyst.