Membrane Reactor for Continuous Solvent Recycling
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Solution Overview
Problem
Chemical reactions requiring low substrate concentrations often result in high solvent usage and inefficient yield due to the formation of unwanted side products, especially when the reaction product is unstable, leading to increased reactor volumes and reduced product purity.
Innovation Solution
A continuous process involving simultaneous addition of a substrate feed and solvent to form a diluted reaction mixture, followed by filtration through a membrane permeable to solvent but impermeable to the reaction product, with recycling of solvent to maintain low substrate concentrations and separate the reaction product from the reactor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If substrate concentration is reduced to avoid side reactions, then product purity is improved, but reactor volume and solvent consumption increase
Solution Approach 1:
The harmful factor (excess solvent) is extracted from the system by using a membrane reactor that separates reaction products from the reaction medium continuously. This allows the reaction to proceed at high dilution without requiring proportionally large solvent volumes, as the solvent is recycled and only the necessary amount remains in the reactor at any given time.
Solution Approach 2:
The membrane reactor enables continuous separation and recycling of solvent, creating a continuous cycle where solvent is reused multiple times. This continuous action maintains high dilution conditions for product purity while reducing total solvent consumption compared to batch processes where solvent must be present throughout the entire reaction duration.
2Manufacturing precision
If high dilution is used to prevent intermolecular side reactions, then product purity is improved, but reactor volume increases
Solution Approach 1:
The membrane reactor extracts and removes reaction products continuously from the reaction zone, allowing the reaction to be conducted at high dilution in a compact reactor volume. The products are taken out as they form, preventing back-reactions and side reactions that would require larger reactor volumes to accommodate.
Solution Approach 2:
The system transitions from a single-phase batch reaction to a two-phase continuous system with separation. By adding the dimension of continuous separation and recycling, the reactor volume can be reduced while maintaining the high dilution conditions necessary for product purity.
3Quantity of substance
If fed-batch process is used to reduce solvent amount, then solvent consumption is reduced, but reaction reversibility leads to high substrate concentration and side products
Solution Approach 1:
The membrane reactor continuously extracts reaction products from the reaction mixture, preventing the reverse reaction by removing products as they form. This allows the use of reduced solvent amounts (similar to fed-batch) while avoiding the accumulation of substrate that leads to side reactions, thus maintaining product purity.
Solution Approach 2:
The system implements feedback control where reaction products are continuously monitored and removed via the membrane separator. This feedback mechanism prevents product accumulation that would drive reverse reactions, allowing efficient use of solvent while maintaining high product purity.
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 significantly reduces solvent consumption and maintains high reaction product yield and purity compared to batch processes, while minimizing the formation of unwanted side products, thus enhancing sustainability in chemical production.
Implementation Method 1
filtration through a membrane permeable to solvent but impermeable to the reaction product
Implementation Method 2
filtration through a membrane permeable to solvent but impermeable to the reaction product
Data Source
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AI summary
Provided herein are processes for carrying out a chemical reaction of a substrate in a diluted reaction mixture. The processes comprise the conducting the reaction mixture comprising reaction product and solvent to a filtration membrane which is permeable to the solvent impermeable to the reaction product; and recycling solvent which permeates the filtration membrane for dilution of the substrate feed.