SMB Adsorption Chamber Segmentation for p-Xylene Recovery
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Solution Overview
Problem
Conventional aromatic compound separation processes are inefficient in p-xylene recovery due to mixing feeds with different compositions into a single adsorption chamber, limiting productivity and reaction equilibrium.
Innovation Solution
Separately injecting high and low p-xylene mixtures into different parts of an adsorption chamber using SMB operation, optimizing the SMB process with specific catalysts and processes like SULFOLANE, STDP, transalkylation, and ISOMAR to enhance p-xylene separation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If feeds with different compositions are mixed and injected into a single adsorption chamber, then the process structure is simple, but the p-xylene productivity and recovery rate are limited
Solution Approach 1:
The single adsorption chamber is segmented into multiple injection zones along the flow direction, allowing separate injection of high p-xylene mixture (first feed) and low p-xylene mixture (second feed). This segmentation enables different regions of the chamber to handle different feed compositions optimally, improving overall p-xylene productivity while maintaining a relatively simple overall process structure.
Solution Approach 2:
Different parts of the adsorption chamber are assigned different functions based on local quality principles. The first injection zone handles high p-xylene concentration feeds while the second injection zone handles low p-xylene concentration feeds. This local differentiation optimizes the separation efficiency and productivity for each feed type without requiring completely separate processing systems.
2Productivity
If all xylene mixtures from 4 sub-processes are injected into the same single part of adsorption chamber, then the injection system is simple, but the operation cannot achieve optimal productivity
Solution Approach 1:
The adsorption chamber is divided into multiple injection positions along the flow direction, with each position receiving specific feed streams from different sub-processes. This segmentation allows each injection zone to be optimized for its specific feed composition, achieving optimal productivity for the STDP process (high p-xylene) and other processes (low p-xylene) simultaneously.
Solution Approach 2:
The adsorption chamber serves multiple functions by accommodating different feed types from four different sub-processes (reformer, isomerization, transalkylation, and STDP) within a single unit. The multi-functional injection system maintains ease of operation while achieving optimal productivity for each process stream through strategic positioning of injection points.
3Manufacturing precision
If high p-xylene mixture and low p-xylene mixture are separately injected into different parts of adsorption chamber, then the p-xylene recovery rate increases significantly, but the injection system becomes more complex
Solution Approach 1:
The adsorption chamber is segmented into distinct injection zones along the flow direction, with the first injection position receiving high p-xylene mixture and the second injection position receiving low p-xylene mixture. This segmentation achieves high separation precision by creating distinct concentration zones that enhance p-xylene recovery rate to up to 98.65%, while the segmentation itself is implemented through a relatively simple multi-point injection configuration.
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
Significantly improves p-xylene productivity and recovery rate, achieving up to 98.65% recovery compared to conventional methods, with potential for increased annual production of 12,000 tons or more.
Implementation Method 1
a method for separating aromatic compounds using SMB operation for adsorptive separation
Data Source
AI summary
Disclosed is a method for separating aromatic compounds using a simulated moving bed (SMB) operation, characterized by injecting each raw material having a different composition into each different part of an adsorption chamber so as to improve the recovery rate. More specifically, the present invention provides a method for separating aromatic compounds for improving p-xylene separation in a p-xylene separation process, by injecting a high p-xylene mixture from selective toluene disproportionation process (STDP) and low p-xylene mixture from other processes (for example, processes of reformer, isomerization reactor and transalkylation of aromatics having 9 carbon atoms) into each different part of an adsorption chamber.