Reactor Segmentation for Foam Control in High-Pressure Gas-Liquid Reactions
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Solution Overview
Problem
In high-pressure gas/liquid biphasic reactions, foam formation impedes the optimal utilization of reaction space and contaminates downstream processes, existing measures for foam reduction increasing technical complexity and being insufficient in many cases.
Innovation Solution
A reactor design with a cylindrical shell divided into a backmixed zone and a zone of limited backmixing, featuring a riser tube and internal elements that prevent backmixing, allowing for intensive gas-liquid contact while minimizing foam entrainment into the riser tube, thus optimizing reaction space utilization and preventing contamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If foam formation occurs in high-pressure gas/liquid biphasic reactions, then gas-liquid contact is enhanced, but reaction space utilization deteriorates and downstream contamination occurs
Solution Approach 1:
The reactor interior is divided into a backmixed zone and a zone of limited backmixing using internal elements (trays, packings, or structured dividers). This segmentation allows foam to form and break in the backmixed zone while preventing it from entering the zone of limited backmixing, thus maintaining high reaction space utilization without sacrificing gas-liquid contact efficiency.
Solution Approach 2:
A riser tube is introduced as an intermediary structure that selectively transports liquid from the backmixed zone to the zone of limited backmixing while excluding foam. The riser tube acts as a mediator that separates the harmful foam phase from the useful liquid phase, allowing continuous liquid flow while preventing foam contamination.
2Object-affected harmful factors
If foam destruction measures are implemented, then foam contamination is reduced, but device complexity increases
Solution Approach 1:
The reactor is segmented into zones with different backmixing characteristics, using simple internal elements like trays or packings that naturally prevent foam transport without requiring complex foam destruction equipment. This structural segmentation achieves foam control through flow management rather than complex mechanical or chemical interventions.
Solution Approach 2:
The riser tube serves as a passive intermediary that physically blocks foam from entering the zone of limited backmixing while allowing liquid to pass through. This simple geometric constraint eliminates the need for complex foam breakers, chemical antifoam systems, or mechanical disruption devices.
3Productivity
If intensive gas-liquid commixing is achieved, then conversion is improved, but foam formation increases
Solution Approach 1:
The reactor interior is divided into a backmixed zone where intensive gas-liquid commixing occurs and a zone of limited backmixing where foam is excluded. Internal elements such as trays, packings, or structured dividers create this segmentation, allowing vigorous mixing in the first zone while preventing foam transport to the second zone.
Solution Approach 2:
The riser tube acts as an intermediary that selectively transports liquid from the backmixed zone to the zone of limited backmixing while excluding foam. This mediator structure enables intensive gas-liquid contact in the backmixed zone without transferring the harmful foam effect to subsequent reaction zones.
4Object-generated harmful factors
If flow management measures are implemented, then foam formation is reduced, but they are insufficient in many cases
Solution Approach 1:
The reactor is divided into distinct zones with internal elements (trays, packings, or structured dividers) that create physical barriers to foam transport. This segmentation provides reliable foam control by preventing foam from moving between zones, overcoming the limitations of conventional flow management alone.
Solution Approach 2:
The riser tube serves as a reliable intermediary structure that passively and consistently prevents foam from entering the zone of limited backmixing. This geometric constraint provides dependable foam control that does not depend on operating conditions or require active control systems.
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 reactor effectively reduces foam formation and contamination, allowing for optimal utilization of high-pressure reaction space and ensuring minimal foam presence in downstream processes, enhancing conversion efficiency and process simplicity.
Implementation Method 1
a riser tube whose lower end is arranged within the backmixed zone and whose upper end opens into the zone of limited backmixing so that liquid from the backmixed zone can ascend into the zone of limited backmixing via the riser tube
Implementation Method 2
the backmixed zone comprises means for introducing gas and liquid and a gas outlet and also comprises at least one mixing apparatus selected from a stirrer, a jet nozzle and means for injecting the gas
Implementation Method 3
DE 196 50 959 A1 describes a process for reducing/avoiding foam formation in chemical and physical transformations of matter in which ascending jet circulation is brought about using gas injection in a reactor which narrows in the downward direction
Data Source
AI summary
A reactor for performing a gas/liquid biphasic high-pressure reaction with a foaming medium, comprising an interior formed by a cylindrical, vertically oriented elongate shell, a bottom and a cap, wherein the interior is divided by internals into a backmixed zone and a zone of limited backmixing, wherein the backmixed zone and the zone of limited backmixing are consecutively traversable by the reaction mixture, wherein the backmixed zone comprises means for introducing gas and liquid and a gas outlet and also comprises at least one mixing apparatus selected from a stirrer, a jet nozzle and means for injecting the gas, and the zone of limited backmixing comprises a reaction product outlet, a first cylindrical internal element which in the interior extends in the longitudinal direction of the reactor and which delimits the zone of limited backmixing from the backmixed zone, backmixing-preventing second internal elements in the form of random packings, structured packings or liquid-permeable trays arranged in the zone of limited backmixing and a riser tube whose lower end is arranged within the backmixed zone and whose upper end opens into the zone of limited backmixing so that liquid from the backmixed zone can ascend into the zone of limited backmixing via the riser tube, wherein flow into the zone of limited backmixing enters from below. The reactor is configured such that the high-pressure reaction space is optimally utilized and contamination of workup steps or subsequent reactions arranged downstream of the high-pressure reaction with foam is substantially avoided. The invention further relates to a process for performing a continuous gas/liquid biphasic high-pressure reaction in the reactor.