Fluidizable Sorbent Desulfurization System
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Solution Overview
Problem
Conventional sulfur removal processes from hydrocarbon fuels, such as hydrodesulfurization, often reduce the octane number of gasoline and require significant hydrogen consumption, and involve high capital and operating costs due to complex equipment designs and particle attrition in fluidized bed reactors.
Innovation Solution
A desulfurization system using fluidizable and circulatable solid particles in a closed-loop process with a fluidized bed reactor, regenerator, and reducer, minimizing equipment and vessel elevation, employing dense phase transport to reduce particle attrition and operating costs, and utilizing zinc oxide-based sorbents with a reduced-valence promoter metal component for continuous sulfur removal and regeneration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional hydrodesulfurization is used to remove sulfur from hydrocarbon fuels, then sulfur removal is achieved, but octane number is reduced and hydrogen consumption is high
Solution Approach 1:
The invention changes the chemical state of the promoter metal from oxidized to reduced-valence form, which fundamentally alters the desulfurization mechanism from hydrogenation-based to direct sulfur capture, thereby removing sulfur without saturating olefins and preserving octane number
Solution Approach 2:
The invention replaces the conventional hydrodesulfurization chemical process with a solid sorbent-based physical/chemical capture process, where reduced-valence promoter metals directly capture sulfur from hydrocarbons without requiring hydrogen addition, thus eliminating octane reduction
2Quantity of substance
If conventional hydrodesulfurization is used to remove sulfur from diesel fuel, then sulfur removal is achieved, but hydrogen consumption is significant
Solution Approach 1:
The invention replaces hydrogen-based chemical desulfurization with a solid sorbent system where reduced-valence promoter metals directly capture sulfur through chemical adsorption, eliminating the need for large amounts of hydrogen while achieving effective sulfur removal from diesel fuel
Solution Approach 2:
The solid sorbent particles act as an intermediary between sulfur in hydrocarbons and the capture mechanism, with reduced-valence promoter metals serving as the active sites that bind sulfur directly without requiring hydrogen as a mediator
3Productivity
If fluidized bed reactors are used for continuous sulfur removal, then continuous desulfurization is achieved, but particle attrition increases and operating costs rise
Solution Approach 1:
The invention changes the physical state and surface properties of the solid particles by reducing the promoter metals to lower valence states, which enhances the mechanical strength and attrition resistance of the particles, allowing them to withstand fluidized bed conditions without excessive wear
Solution Approach 2:
The invention uses composite solid particles containing metal oxide and reduced-valence promoter metals, where the combination of materials provides both the chemical functionality for sulfur capture and the mechanical durability needed for continuous circulation in fluidized bed reactors
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 system achieves continuous sulfur removal from hydrocarbon fuels while maintaining octane number and reducing hydrogen consumption, minimizing capital and operating expenses by optimizing particle circulation and equipment layout, and enhancing attrition resistance of sorbent particles.
Implementation Method 1
the promoter metal and metal oxide components of the regenerable sorbent cooperate to remove sulfur from the hydrocarbon and store the removed sulfur on/in the sorbent via the conversion of the metal oxide component (e.g., ZnO) to a metal sulfide (e.g., ZnS)
Implementation Method 2
the metal sulfide (e.g, ZnS) in the sulfur-loaded sorbent is returned to its original metal oxide form (e.g., ZnO) via reaction with the oxygen-containing regeneration stream
Implementation Method 3
the oxidized promoter metal component is reduced to thereby return the sorbent to an optimum sulfur-removing state having a metal oxide component (e.g., ZnO) and a reduced-valence promoter component (e.g., Ni)
Implementation Method 4
employing a sorbent composition that is both fluidizable and circulatable allows for substantially continuous removal of sulfur from a hydrocarbon-containing fluid stream and substantially continuous sorbent regeneration
Data Source
AI summary
A hydrocarbon desulfurization system that circulates fluidizable solid particles through a fluidized bed reactor, a fluidized bed regenerator, and a fluidized bed reducer to thereby provide for substantially continuous desulfurization of a hydrocarbon-containing fluid stream and substantially continuous regeneration of the solid particles. A novel transport system is employed for transporting the solid particles between the reactor, the regenerator, and the reducer. The transport system uses close-coupled vessels and gravity flow between various vessels to minimize equipment cost and particle attrition.