Fluidized Bed Reactor Cracking with Continuous Coke Regeneration
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Solution Overview
Problem
Existing Fluid Catalytic Cracking (FCC) reactor and regenerator systems are not designed for direct conversion of light hydrocarbons due to the drastically different reaction conditions, requiring high temperatures that lead to coke formation, reactor plugging, and catalyst deactivation, while also being energy-inefficient.
Innovation Solution
A fluidized bed reactor system with a riser and catalyst regeneration unit that heats light hydrocarbons and regenerated catalysts to high temperatures for cracking, followed by coke combustion to regenerate the catalyst, allowing continuous operation and energy-efficient production of hydrogen and value-added chemicals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high temperatures are used for catalytic cracking of light hydrocarbons, then conversion efficiency is improved, but coke formation increases leading to reactor plugging and catalyst deactivation
Solution Approach 1:
The patent converts the harmful coke deposits into a beneficial resource by introducing an oxygen-containing stream to oxidize and remove the coke from the catalyst surface. This regeneration process restores catalyst activity, allowing continuous operation at high temperatures without the usual deactivation issues.
Solution Approach 2:
The patent changes the chemical environment parameter by introducing oxygen-containing streams (air or oxygen) to the reaction system. This parameter change enables selective oxidation of coke deposits while maintaining the high temperature conditions necessary for efficient hydrocarbon conversion.
2Speed
If high temperatures are used for catalytic cracking, then reaction rate is improved, but energy consumption increases
Solution Approach 1:
The patent converts the energy-intensive high-temperature operation into a more efficient process by using the oxygen-containing stream to oxidize coke deposits. This oxidation process occurs at lower temperatures than the cracking reaction, reducing the overall energy consumption while maintaining high reaction rates through the regenerated catalyst.
Solution Approach 2:
The patent enables continuous operation by periodically regenerating the catalyst in-situ. The catalyst remains active throughout the process through continuous or periodic oxygen stream introduction, eliminating the need for catalyst replacement and reducing energy losses associated with process interruptions.
3Adaptability or versatility
If conventional FCC systems are used for light hydrocarbon conversion, then existing infrastructure is utilized, but the system is not designed for these conditions leading to suboptimal performance
Solution Approach 1:
The patent makes the conventional FCC system universally applicable to both heavy and light hydrocarbons by introducing the oxygen-containing stream for coke removal. This modification allows the same reactor system to efficiently convert light hydrocarbons while maintaining its original infrastructure and operational framework.
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 high conversion of light hydrocarbons to hydrogen and C2 to C10 hydrocarbons efficiently, minimizing coke formation and catalyst deactivation, while reducing energy costs and extending reactor life.
Implementation Method 1
contact with one or more heat sources to generate a first heated light hydrocarbon feed stream and a first heated regenerated catalyst
Implementation Method 2
crack the first heated light hydrocarbon feed stream in the presence of the first heated regenerated catalyst to produce a first product effluent stream comprising hydrogen and spent catalyst comprising coke deposits
Implementation Method 3
cracking the heated light hydrocarbon feed stream
Implementation Method 4
combusting, in a catalyst regeneration unit operatively connected to the fluidized bed reactor, the spent catalyst comprising the coke deposits to produce a second regenerated catalyst
Data Source
AI summary
A fluidized bed reactor system includes a riser configured to receive a light hydrocarbon feed stream and a first regenerated catalyst in a bottom portion of the riser, the riser containing one or more heat sources in the bottom portion to generate a heated light hydrocarbon feed stream and a heated regenerated catalyst, and a reaction chamber in a top portion of the riser in fluid communication with a fluidized bed reactor for cracking the heated light hydrocarbon feed stream in the presence of the heated regenerated catalyst flowing upwards from the bottom portion to produce a product effluent stream comprising hydrogen and spent catalyst comprising coke deposits, and a catalyst regeneration unit operatively connected to the fluidized bed reactor and the riser, the catalyst regeneration unit being configured to receive the spent catalyst flowing downwards and combust the coke deposits to produce a second regenerated catalyst.