Reactive Stripping for FCC Yield Optimization
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Solution Overview
Problem
Existing fluid catalytic cracking (FCC) technologies face challenges in optimizing product yield and quality without reducing unit capacity, as recycling streams in the reaction zone decreases total capacity and introduces temperature increases that affect product profiles and power consumption.
Innovation Solution
A reactive stripping process is implemented in the FCC unit's stripping section, where hydrocarbon streams are introduced to react with spent FCC catalyst, allowing for selective catalytic cracking at normal operational conditions, optimizing product yield and quality without compromising the reaction zone's production capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If hydrocarbon streams are recycled to the reaction zone to optimize product yield and quality, then product quality (octane number) is improved, but unit capacity is reduced
Solution Approach 1:
The invention divides the cracking process into two distinct zones: a reaction zone for primary cracking and a stripping zone for secondary cracking of recycled hydrocarbon streams. This segmentation allows each zone to perform its specific function optimally without interfering with the other, thereby maintaining unit capacity while improving product quality through selective cracking in the stripping zone.
Solution Approach 2:
The stripping zone acts as an intermediary between the reaction zone and the product separation system. It provides a controlled environment where recycled hydrocarbon streams can undergo selective cracking with spent catalyst, optimizing product distribution without directly impacting the reaction zone's throughput capacity.
2Quantity of substance
If spent catalyst is recycled to the reaction zone to favor hydrocarbon yield, then product yield is improved, but unit capacity is reduced
Solution Approach 1:
The invention segments the catalyst circulation path into distinct functional zones: fresh catalyst enters the reaction zone for primary cracking, while spent catalyst is directed to the stripping zone for secondary cracking of hydrocarbon streams. This segmentation enables optimized hydrocarbon yield in the stripping zone without reducing the reaction zone's processing capacity.
Solution Approach 2:
The spent catalyst, after completing its primary function in the reaction zone, is reused in the stripping zone to crack recycled hydrocarbon streams. This self-service approach maximizes the utilization of catalyst activity and extends its productive life, improving overall hydrocarbon yield without requiring additional catalyst or reducing unit capacity.
3Loss of substance
If stripper temperature is increased to improve hydrocarbon recovery from catalyst surface, then desorption efficiency is improved, but power consumption and reaction severity increase
Solution Approach 1:
The stripping zone serves as an intermediary that utilizes the thermal energy of spent catalyst to drive hydrocarbon desorption and secondary cracking. This approach avoids the need for additional external heating, thereby improving hydrocarbon recovery without increasing power consumption or overall reaction severity.
Solution Approach 2:
The spent catalyst, carrying thermal energy from the reaction zone, serves as the heat source for the stripping zone. This self-service heat transfer enables efficient hydrocarbon desorption and secondary cracking without requiring external energy input, thereby improving recovery efficiency while maintaining energy balance.
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 process achieves a 40% reduction in sulfur content and improves octane numbers while maintaining conventional stripping efficiency, enhancing the yield of relevant products and meeting environmental standards without increasing power consumption or reducing unit capacity.
Implementation Method 1
reactive stripping of a fluid catalytic cracking (FCC) unit catalyst, generating products that optimize the yield and quality of fluid catalytic cracking products
Implementation Method 2
The stripping step of the catalyst used to remove the residue hydrocarbons has been considered, recently, to be relevant to improve the operation of the FCC unit
Data Source
AI summary
A process and device to optimize the yield of fluid catalytic cracking products through a reactive stripping process are disclosed. One or more hydrocarbon streams (3) are introduced in an intermediary region of the stripper (1) of a fluid catalytic cracking unit (FCC), from a device that allows a homogeneous distribution with adequate dispersion. This/these stream(s) react(s) with the catalyst of FCC, although its activity is reduced due to the adsorption of hydrocarbons in the reaction zone, generating products that improve and/or change the global distribution of products, providing a refinery profile adequate to meet quality demands and requirements.