Oxidative Desulfurization of Oil Fractions Using FCC Unit
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for desulfurization and denitrogenation of hydrocarbon feedstocks face challenges such as inefficiency in removing sulfur from sterically hindered compounds, high energy consumption, catalyst deactivation, and production of coke byproducts, which complicates the process and increases costs.
Innovation Solution
A method involving oxidative desulfurization and denitrogenation using a fluid catalytic cracking (FCC) unit, where a hydrocarbon feedstock is contacted with an oxidizing agent and a catalyst in a mild oxidation reactor, followed by solvent extraction and subsequent processing in a fluid catalytic cracking unit to recover and recycle hydrocarbons, oxidized sulfur, and nitrogen compounds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional hydrodesulfurization or hydrogenation is used to reduce sulfur content, then sulfur removal efficiency improves, but fuel lubricity deteriorates and excessive wear of fuel pumps and injectors occurs
Solution Approach 1:
The patent changes the chemical approach from hydrogenation to oxidative desulfurization, altering the reaction mechanism from adding hydrogen to oxidizing sulfur compounds. This parameter change allows sulfur removal while preserving the hydrocarbon structure that provides lubricity, thus resolving the contradiction between sulfur content reduction and fuel lubricity maintenance
2Manufacturing precision
If severe operating conditions (high hydrogen partial pressure, high temperature, high catalyst volume) are used to remove sterically hindered sulfur compounds, then sulfur removal efficiency improves, but energy consumption increases and catalyst life cycle decreases
Solution Approach 1:
The patent employs strong oxidants such as peracetic acid, m-chloroperbenzoic acid, or hydrogen peroxide to accelerate the oxidation of sterically hindered sulfur compounds. This allows the reaction to proceed under mild conditions (low temperature and pressure) while maintaining high sulfur removal efficiency, thereby resolving the contradiction between sulfur removal effectiveness and energy consumption
Solution Approach 2:
The patent replaces the mechanical/thermal approach (high temperature and pressure) with a chemical approach (oxidative desulfurization using strong oxidants and selective catalysts). This substitution enables sulfur removal from hindered compounds under mild conditions, resolving the contradiction between sulfur content reduction and energy consumption
3Manufacturing precision
If oxidative desulfurization is used to remove sulfur compounds, then sulfur removal efficiency improves, but oxidized sulfur compounds (sulfones) are produced as byproducts that require disposal
Solution Approach 1:
The patent converts the harmful oxidized sulfur compounds (sulfones) into a beneficial resource by using them as feedstock for hydrocracking to produce diesel fuel. This transforms the waste disposal problem into a value-added process, resolving the contradiction between sulfur removal efficiency and harmful byproduct generation
4Manufacturing precision
If chemical hydrotreating is used to reduce sulfur and aromatics contents, then sulfur content improves, but fuel lubricity deteriorates
Solution Approach 1:
The patent changes the chemical approach from hydrotreating (hydrogenation) to oxidative desulfurization, altering the reaction mechanism. This parameter change allows sulfur removal while preserving the hydrocarbon structure that provides lubricity, thus resolving the contradiction between sulfur content reduction and fuel lubricity maintenance
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 method effectively reduces sulfur and nitrogen content in hydrocarbon feedstocks under low-severity conditions, allowing for the recovery and disposal of usable compounds, improving process efficiency and reducing environmental impact.
Implementation Method 1
contacting the hydrocarbon feedstock with an oxidizing agent in the oxidation reactor under conditions sufficient to selectively oxidize sulfur compounds and nitrogen compounds present in the hydrocarbon feedstock
Implementation Method 2
separating the hydrocarbons, the oxidized sulfur compounds, and the oxidized nitrogen compounds in the oxidized hydrocarbon stream by solvent extraction with a polar solvent
Implementation Method 3
supplying the first residue stream to a fluid catalytic cracking unit, wherein the fluid catalytic cracking unit is operative to catalytically crack the oxidized sulfur and the oxidized nitrogen
Data Source
AI summary
Embodiments provide a method and apparatus for recovering components from a hydrocarbon feedstock. According to at least one embodiment, the method includes 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 and nitrogen compounds present in the hydrocarbon feedstock, separating the hydrocarbons, the oxidized sulfur compounds, and the oxidized nitrogen compounds by solvent extraction, collecting a residue stream that includes the oxidized sulfur compounds and the oxidized nitrogen compound, supplying the residue stream to a fluid catalytic cracking unit, and recycling liquid products produced by the fluid catalytic cracking unit to the oxidation reactor to selectively oxidize sulfur compounds in the liquid products, the portion of the liquids products including at least one of light cycle oils and heavy cycle oils.