Oxidative Desulfurization via Solvent Deasphalting
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Solution Overview
Problem
Conventional methods for desulfurization and denitrogenation of hydrocarbon feedstocks face challenges such as high energy consumption, catalyst deactivation, and inefficient removal of sterically hindered sulfur compounds, leading to decreased yield and product quality, and require severe operating conditions which are costly and complex.
Innovation Solution
A method involving oxidative desulfurization and denitrogenation using a catalyst and oxidant in a mild oxidation reactor, followed by solvent extraction and deasphalting to separate and recover oxidized sulfur and nitrogen compounds, allowing for the production of high-purity hydrocarbon streams with reduced sulfur and nitrogen content.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional hydrotreating or hydrogenation is used to remove sulfur and nitrogen from hydrocarbons, then sulfur and nitrogen content is reduced, but fuel lubricity decreases and excessive wear occurs on fuel pumps and injectors
Solution Approach 1:
The patent changes the chemical state of sulfur compounds from reduced forms (sulfides) to oxidized forms (sulfones, sulfoxides) through oxidation reactions. This parameter change allows effective desulfurization while preserving fuel lubricity, as the oxidized sulfur compounds can be removed without excessive hydrogenation that would degrade lubricating components
Solution Approach 2:
The patent extracts oxidized sulfur and nitrogen compounds from the hydrocarbon stream using selective solvents or adsorbents. This extraction approach removes the harmful sulfur and nitrogen compounds while leaving the lubricating components of the fuel intact, thereby maintaining fuel lubricity
2Productivity
If severe operating conditions are used in conventional desulfurization processes, then sulfur removal efficiency is improved, but operational costs increase and process complexity increases
Solution Approach 1:
Instead of using conventional reduction-based hydrotreating under severe conditions, the patent inverts the approach by using oxidation to convert sulfur compounds to removable forms. This inversion allows milder operating conditions while achieving effective desulfurization, thereby reducing process complexity and operational costs
Solution Approach 2:
The patent replaces the mechanical/thermal severe conditions (high pressure, high temperature) of conventional hydrotreating with chemical oxidation followed by selective extraction. This substitution achieves comparable or better sulfur removal efficiency under milder conditions, reducing equipment complexity and operational costs
3Productivity
If catalysts are used in conventional hydrotreating, then sulfur removal is enhanced, but catalyst deactivation occurs and regeneration is required
Solution Approach 1:
The patent converts the harmful sulfur compounds into oxidized forms (sulfones, sulfoxides) that are more easily separated from the fuel stream. This conversion eliminates the need for catalyst regeneration, as the oxidized compounds can be removed through extraction or adsorption without deactivating the catalyst
Solution Approach 2:
The patent introduces an intermediary oxidation step that converts sulfur compounds to a form that can be easily separated. This intermediary process enhances sulfur removal efficiency while protecting the catalyst from deactivation, as the oxidized compounds do not bind strongly to the catalyst active sites
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 enables efficient removal and recovery of sulfur and nitrogen compounds under low-severity conditions, improving product quality and reducing operational costs by maintaining mild operating temperatures and pressures, while avoiding the need for extensive hydrogen use and catalyst regeneration.
Implementation Method 1
contacting the hydrocarbon feedstock with an oxidant in the presence of a catalyst under conditions sufficient to selectively oxidize sulfur-containing compounds
Implementation Method 2
extracting the treated hydrocarbon stream with a polar solvent to produce an extracted hydrocarbon stream and a mixed stream
Implementation Method 3
separating the mixed stream using a distillation column into a first recovered polar solvent stream and a first residue stream; and supplying the first residue stream to a deasphalting unit to produce a deasphalted oil stream and a pitch stream
Data Source
AI summary
Embodiments provide a method and apparatus for upgrading a hydrocarbon feedstock. According to at least one embodiment, 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 and nitrogen compounds present in the hydrocarbon feedstock; (b) separating the hydrocarbons and the oxidized sulfur and nitrogen compounds by solvent extraction; (c) collecting a first residue stream that includes the oxidized sulfur and oxidized nitrogen compounds; (d) supplying the first residue stream to a deasphalting unit; (e) supplying the hydrocarbons to an adsorption column to produce a high purity hydrocarbon product and a second residue stream; and (f) supplying spent adsorbent to the deasphalting unit to remove additional contaminants from the high purity hydrocarbon product in the deasphalting unit.