Oxidative Desulfurization via Solvent Deasphalting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for desulfurization and denitrogenation of hydrocarbon feedstocks face inefficiencies, particularly at low severity conditions, and require costly severe operating conditions, high hydrogen usage, and energy-intensive processes, which lead to decreased yield and catalyst deactivation, and the subsequent disposal of sulfur and nitrogen compounds poses environmental and economic challenges.
Innovation Solution
A method and apparatus for oxidative desulfurization involving an oxidation reactor with a catalyst and oxidant, followed by solvent extraction and deasphalting, allowing for the selective oxidation of sulfur and nitrogen compounds, their separation, and subsequent recovery and disposal as usable products, reducing the need for external hydrogen and severe conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional hydrodesulfurization is used to remove sulfur from hydrocarbon feedstocks, then sulfur content is reduced, but severe operating conditions (high temperature, high pressure) are required which decrease yield and catalyst life
Solution Approach 1:
The patent changes the fundamental reaction parameters from reduction (hydrodesulfurization requiring high T, P, H2) to oxidation (odesulfurization at mild conditions). This parameter change enables sulfur removal under ambient or near-ambient conditions, preserving yield and catalyst life while achieving the same desulfurization goal.
Solution Approach 2:
The patent replaces the mechanical/thermal intensity of conventional hydrodesulfurization (high temperature, high pressure equipment) with a chemical oxidation approach using oxidants and catalysts that operate under mild conditions. This substitution eliminates the need for severe operating conditions and their associated equipment complexity.
2Manufacturing precision
If severe operating conditions are applied to remove sterically hindered sulfur compounds, then sulfur removal efficiency improves, but catalyst deactivation increases and yield decreases
Solution Approach 1:
The patent changes the reaction mechanism from thermal/catalytic reduction requiring severe conditions to oxidation chemistry that proceeds efficiently under mild conditions. This parameter change specifically addresses sterically hindered compounds by using oxidants that can access and react with sulfur atoms regardless of steric hindrance, maintaining high removal efficiency without catalyst deactivation.
3Quantity of substance
If hydrogenation is used to reduce sulfur and aromatic compounds, then sulfur content decreases, but fuel lubricity is reduced causing excessive wear
Solution Approach 1:
The patent replaces hydrogenation (a reduction process requiring H2 and severe conditions) with oxidation. This substitution removes sulfur through oxidation to sulfones/sulfonic acids that can be separated, rather than through hydrogenation to H2S. The hydrocarbon structure and lubricity properties are preserved because oxidation selectively targets sulfur without altering the hydrocarbon backbone.
Solution Approach 2:
The patent converts the harmful sulfur compounds into oxidized forms (sulfones, sulfonic acids) that have different properties - they become more polar and easier to separate via extraction or deasphalting. This conversion maintains the beneficial hydrocarbon structure while removing the harmful sulfur, avoiding the lubricity loss associated with hydrogenation.
4Quantity of substance
If oxidative desulfurization is used to remove sulfur under mild conditions, then sulfur content is reduced and catalyst life is extended, but oxidized sulfur compounds require separation and disposal
Solution Approach 1:
The oxidation process changes the chemical parameters of sulfur compounds, converting them from nonpolar to polar forms (sulfones, sulfonic acids). This parameter change enables separation through polarity-based methods like solvent extraction or deasphalting, which are simpler and operate under milder conditions than the severe separation requirements of conventional hydrodesulfurization.
Solution Approach 2:
The patent employs extraction or deasphalting to take out the oxidized sulfur compounds from the hydrocarbon stream. These separation methods exploit the polarity difference between oxidized sulfur compounds and hydrocarbons, allowing selective removal through solvent extraction or selective precipitation during deasphalting, simplifying the overall separation 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
This approach effectively reduces sulfur and nitrogen content in hydrocarbon feedstocks under mild conditions, enhancing product quality, extending catalyst life, and providing a means for the recovery and utilization of oxidized sulfur and nitrogen compounds, thus addressing environmental and economic concerns.
Implementation Method 1
contacting the hydrocarbon feedstock in the oxidation reactor with an oxidant in the presence of a catalyst and under conditions sufficient to selectively oxidize sulfur containing compounds
Implementation Method 2
contacting the hydrocarbon feedstock in the oxidation reactor with an oxidant in the presence of a catalyst
Implementation Method 3
separating the hydrocarbons and the oxidized sulfur compounds in the oxidized hydrocarbon stream by solvent extraction with a polar solvent
Implementation Method 4
supplying the first residue stream to a deasphalting unit to produce a deasphalted oil stream and a pitch stream, wherein the pitch stream includes a substantial portion of the oxidized sulfur containing compounds
Data Source
AI summary
A method and apparatus for upgrading a hydrocarbon feedstock is provided. The method includes the steps of (a) supplying a hydrocarbon feedstock to an oxidation reactor, wherein the hydrocarbon feedstock is oxidized in the presence of a catalyst under conditions sufficient to selectively oxidize sulfur compounds present in the hydrocarbon feedstock; (c) separating the hydrocarbons and the oxidized sulfur compounds by solvent extraction; (d) collecting a residue stream that includes the oxidized sulfur compounds; and (e) supplying the residue stream to a deasphalting unit.