Hydroprocessing Fluidized Reactor With Internal Riser
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Solution Overview
Problem
Existing hydroprocessing methods face challenges with pressure drop limitations and diffusion issues in fixed beds, and the use of fluid catalytic cracking processes at high pressure and with hydrogen poses safety hazards and maintenance issues.
Innovation Solution
A hydroprocessing method and apparatus utilizing a fluidized reactor with an internal riser contained within a vessel, allowing for smaller catalyst sizes and the use of hydrogen and higher pressures, which reduces catalyst loading and pressure, and enables processing of difficult feeds like crude oil and coal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If a fixed bed with larger catalyst diameter is used, then pressure drop across the bed is reduced, but diffusion of oil into the catalyst is impeded
Solution Approach 1:
The patent transitions from a static fixed bed to a dynamic fluidized bed system where catalyst particles are suspended and circulated. This dynamic state allows small catalyst particles to be transported through the system without creating excessive pressure drop, as the fluidizing gas lifts the particles and maintains them in a suspended state, enabling both high diffusion efficiency and acceptable pressure characteristics.
Solution Approach 2:
The invention uses gas flow to fluidize and transport catalyst particles through the reactor. By controlling the gas velocity, the system achieves fluidization of fine catalyst particles, allowing them to behave like a fluid and flow through the reactor without clogging or creating excessive pressure drop, thus enabling the use of small catalyst particles for improved diffusion.
2Productivity
If a fluid catalytic cracking process is used with smaller catalyst size, then diffusion of oil into the catalyst is improved, but safety hazards arise from operating at high pressure with hydrogen
Solution Approach 1:
The patent changes the operating parameters by using a fluidized bed configuration that allows operation at lower pressures compared to conventional high-pressure hydrocracking. The fluidization mechanism enables efficient mass transfer with smaller catalyst particles while maintaining safer operating conditions, thus achieving both improved diffusion and enhanced safety.
3Productivity
If an external riser is used with a reaction vessel, then fluidized bed operation is achieved, but maintenance issues arise with expansion joints in high pressure equipment
Solution Approach 1:
The patent employs an internal riser design where the riser is nested within the reactor vessel. This configuration eliminates the need for external expansion joints that connect to the reactor shell, as the riser is completely contained within the pressure boundary. The internal positioning allows for simpler maintenance and eliminates the differential expansion issues between internal and external components.
4Productivity
If a fixed bed with smaller catalyst diameter is used, then catalyst activity is improved, but pressure drop across the bed increases
Solution Approach 1:
The system transitions from a static fixed bed to a dynamic fluidized bed, allowing small catalyst particles to be suspended and circulated. This dynamic operation enables the use of high-surface-area small particles for improved catalyst activity while the fluidizing gas prevents excessive pressure drop by keeping particles suspended and facilitating smooth flow through the reactor.
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 fluidized reactor design enhances catalyst activity, reduces pressure, and allows for the processing of challenging feeds by minimizing the need for expansion joints and enabling safer operation with hydrogen, while maintaining efficient hydroprocessing.
Implementation Method 1
a fluidized reactor with an internal riser contained within a vessel, allowing for smaller catalyst sizes and the use of hydrogen and higher pressures
Implementation Method 2
one or more separation devices may be positioned above the internal riser for separating a hydroprocessed product from a catalyst
Data Source
AI summary
One exemplary embodiment can be a hydroprocessing method. The hydroprocessing method can include providing a feed and a stream including hydrogen to a vessel. The vessel may have a catalyst collector and an internal riser. Generally, a catalyst circulates within the vessel by at least partially rising within the internal riser.