Reactor System with Interstage Diverter for Propylene Yield
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for producing light olefins, such as ethylene and propylene, from non-petroleum based raw materials, like methanol, face challenges in achieving high yields of propylene, which is driven by the growth rate disparity between propylene and ethylene markets, and existing technologies struggle to efficiently convert oxygenates into propylene while minimizing by-products.
Innovation Solution
A reactor system with multiple reactors connected in fluid flow communication, featuring a diverter for interstage product removal, and utilizing dual-function catalysts like ZSM-5 or SAPO-34, along with a diluent like steam, to selectively convert oxygenates into propylene and interconvert C2 and C4+ olefins, optimizing conditions for propylene production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a single reactor system is used for converting oxygenates to light olefins, then the process is simple to operate, but the ability to independently control catalysts and conditions for optimizing propylene production is limited
Solution Approach 1:
The reactor system is divided into multiple reactor beds (first reactor bed, second reactor bed, third reactor bed) that can be independently controlled. Each bed can contain different catalysts or operate under different conditions, allowing independent optimization of propylene production while maintaining overall process simplicity through modular design.
2Ease of manufacture
If conventional single-stage conversion is used, then the process is straightforward, but propylene yield is insufficient to meet market growth demands
Solution Approach 1:
The conversion process is segmented into multiple reactor beds with different catalyst systems. The first bed uses a catalyst for initial conversion, the second bed uses a different catalyst for further conversion, and the third bed provides additional conversion capacity. This segmentation enables higher overall propylene yield while maintaining a straightforward multi-stage process configuration.
Solution Approach 2:
Different catalysts are placed in different reactor beds to create local quality variations optimized for specific conversion stages. This allows each bed to perform its specific function optimally, with the first bed optimized for initial oxygenate conversion, the second for propylene formation, and the third for final conversion and by-product management.
3Productivity
If multiple reactor beds are used with interstage product removal, then propylene yield and control are improved, but the device complexity increases
Solution Approach 1:
The reactor system is segmented into three distinct reactor beds with a diverter positioned between the first and second beds. This segmentation enables interstage product removal where propylene can be selectively diverted after the first bed, preventing over-conversion and improving overall yield. The modular segmented design manages complexity by creating distinct functional zones.
Solution Approach 2:
The diverter device extracts propylene from the product stream between the first and second reactor beds. This extraction prevents propylene from undergoing further unwanted reactions in subsequent beds, thereby improving propylene yield and selectivity. The diverter takes out the desired product at the optimal point in the conversion process.
4Device complexity
If by-products are not managed effectively, then the process is simpler, but selectivity for propylene production decreases
Solution Approach 1:
Different catalysts are used in different reactor beds to create local quality variations that manage by-product formation. The first bed uses a catalyst optimized for initial conversion with minimal by-products, the second bed uses a catalyst optimized for propylene formation with high selectivity, and the third bed handles remaining conversion. This local optimization of catalyst properties in each zone improves overall propylene selectivity while managing by-products through distributed catalyst functionality.
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 approach enhances propylene yields by allowing independent control of catalysts and conditions in each reaction zone, reducing by-product formation, and improving thermal efficiency, thereby addressing the market-driven need for increased propylene production.
Implementation Method 1
utilizing dual-function catalysts like ZSM-5 or SAPO-34, along with a diluent like steam, to selectively convert oxygenates into propylene and interconvert C2 and C4+ olefins
Data Source
AI summary
The present invention provides a reactor system having: (1) a plurality of reactors connected in fluid flow communication and having at least one pair of reactors separated by an interstage position; (2) a line for supplying a reactant feed stream separately to an inlet of more than one of the plurality of reactors; and (3) a diverter in fluid communication with the interstage position and capable of directing a first portion of a product stream exiting one reactor in said pair of reactors to a first location and a second portion of the product flow stream to an inlet of another reactor in said pair of reactors.