Oxidative Desulfurization of Diesel Using Cage Catalyst
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Solution Overview
Problem
Current oxidative desulfurization processes for hydrocarbon mixtures, such as diesel oil, face limitations in selectivity and scalability due to the use of biphasic reaction systems, which hinder their effectiveness in large-scale commercial applications.
Innovation Solution
The process involves using a cage structure catalyst and a co-catalyst with an aqueous oxidizing agent to oxidize sulfur species in hydrocarbon mixtures, followed by solvent extraction and subsequent steps like solvent stripping and polishing to achieve high selectivity and efficiency in sulfur removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If biphasic reaction systems are used for oxidative desulfurization, then sulfur removal capability is achieved, but selectivity and scalability are limited
Solution Approach 1:
A phase transfer catalyst is introduced as an intermediary substance to facilitate the reaction between the aqueous oxidizing agent and organosulfur compounds in the hydrocarbon phase. The phase transfer catalyst mediates mass transfer across the liquid-liquid interface, enabling selective oxidation of sulfur compounds while maintaining biphasic system advantages.
Solution Approach 2:
The patent modifies reaction parameters including oxidizing agent concentration, phase transfer catalyst dosage, temperature, and contact time to optimize both sulfur removal efficiency and selectivity. By carefully controlling these parameters, the process achieves high selectivity for sulfur compounds over hydrocarbon components.
2Quantity of substance
If biphasic reaction systems are used for oxidative desulfurization, then sulfur removal capability is achieved, but scalability to large-scale commercial applications is hindered
Solution Approach 1:
The phase transfer catalyst serves as a scalable intermediary that facilitates rapid mass transfer and reaction kinetics. This mediator enables the process to be scaled from laboratory to commercial dimensions by maintaining efficient interfacial reaction rates throughout the larger reactor volume.
Solution Approach 2:
The patent optimizes reaction conditions including temperature, oxidizing agent dosage, and phase ratio to enable scalable operation. These parameter adjustments ensure that reaction efficiency and sulfur removal capability are maintained across different scales of operation.
3Manufacturing precision
If oxidized sulfur compounds are removed by solvent extraction, then sulfur content is reduced to below 10 ppm, but process complexity increases
Solution Approach 1:
The patent employs liquid-liquid extraction to separate oxidized sulfur compounds from the hydrocarbon phase. A selective solvent extracts the polar oxidized sulfur species (sulfones, sulfoxides) from the non-polar hydrocarbon phase, achieving sulfur content reduction to below 10 ppm through selective phase separation.
Solution Approach 2:
The process utilizes phase separation between immiscible liquid phases to remove sulfur compounds. The oxidized sulfur compounds preferentially partition into the aqueous or solvent phase, which is then separated from the hydrocarbon phase, achieving high purity fuel without complex separation equipment.
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 effectively reduces sulfur content in diesel oil to below 10 ppm, utilizing catalysts like polyoxometalates and porphyrins, and solvent extraction with polar solvents like acetonitrile and methanol, ensuring high selectivity and recyclability of solvents, thereby enhancing the desulfurization process.
Implementation Method 1
treating a hydrocarbon mixture with an aqueous oxidizing agent in the presence of a cage structure catalyst and a co-catalyst
Implementation Method 2
oxidative conversion of organosulfur compounds in liquid hydrocarbon mixtures
Implementation Method 3
selectively removing the oxidized compounds by solvent extraction
Data Source
AI summary
The process for the desulfurization of a sulfur-containing hydrocarbon mixture, such as a full-range, hydrotreated diesel oil, is accomplished with an aqueous oxidizing agent in the presence of a catalyst and a co-catalyst, and thereafter selectively removing the oxidized compounds by solvent extraction. Optionally, the foregoing steps are followed by solvent stripping and recovery, and a final polishing step.