Two-Reactor Glycol Process Segmentation
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Solution Overview
Problem
Current continuous flow processes for producing ethylene and propylene glycols from saccharide feedstocks face challenges such as decomposition due to high reactant concentrations in plug flow reactors and incomplete reaction in stirred tank reactors, leading to reduced yields and by-product formation.
Innovation Solution
A two-reactor system is employed, where the first reactor operates with mixing to achieve substantial conversion of saccharides, and the second reactor operates in plug flow to further react the product stream with hydrogen, minimizing by-product formation and ensuring complete conversion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a plug flow reactor is used for continuous flow process, then productivity is improved, but decomposition and by-product formation increase due to high reactant concentrations
Solution Approach 1:
The reaction system is divided into two separate reactors: a first reactor operating with mixing to prevent decomposition, and a second reactor operating in plug flow mode to achieve complete conversion. This segmentation allows each reactor to optimize for its specific function, resolving the contradiction between productivity and by-product formation.
2Object-generated harmful factors
If a continuous flow stirred tank reactor is used, then decomposition is prevented due to reduced reactant concentrations, but conversion is incomplete resulting in reduced yield
Solution Approach 1:
The system segments the reaction into two stages: the first reactor (stirred tank) prevents decomposition through mixing, while the second reactor (plug flow) ensures complete conversion. This segmentation allows both benefits to be achieved in sequence.
Solution Approach 2:
The first reactor performs preliminary conversion of saccharides to intermediates under mixing conditions that prevent decomposition. This preliminary action prepares the reaction mixture for the second reactor, where complete conversion occurs without the risk of decomposition from high concentrations.
3Productivity
If a single reactor operates with mixing, then conversion is improved, but by-product formation increases due to high reactant concentrations at the start of reaction
Solution Approach 1:
The reaction is segmented into two reactors with different flow patterns. The first reactor handles the initial conversion with mixing to prevent by-products, while the second reactor completes the reaction in plug flow mode, achieving both high conversion and low by-product formation.
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 enables nearly complete conversion of starting materials to ethylene and propylene glycols, reducing by-product formation and improving overall yield by maintaining consistent reactant concentrations and optimizing reaction conditions in each reactor.
Implementation Method 1
providing the starting material and hydrogen to a first reactor, which first reactor operates with mixing
Implementation Method 2
supplying at least a portion of the first reactor product stream to a second reactor, which reactor operates essentially in a plug flow manner
Implementation Method 3
reacting said starting material and hydrogen in the presence of solvent and a catalyst system
Implementation Method 4
reacting said starting material and hydrogen in the presence of solvent and a catalyst system
Data Source
AI summary
The invention provides a process for the preparation of ethylene glycol and 1, 2-propylene glycol from starting material comprising one or more saccharides, wherein the process comprises the steps of i) providing the starting material and hydrogen to a first reactor, which first reactor operates with mixing; ii) reacting said starting material and hydrogen in the first reactor in the presence of solvent and a catalyst system; iii) continuously removing a first reactor product stream from the first reactor; iv) supplying at least a portion of the first reactor product stream to a second reactor, which reactor operates essentially in a plug flow manner; and v) further reacting the first reactor product stream with hydrogen in the presence of a solvent and optionally a catalyst system in the second reactor.