Ethyleneamine Production via MEG Amination and Ammonia Separation
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Solution Overview
Problem
The production of ethylenediamine (EDA) from monoethylene glycol (MEG) faces challenges due to the complexity of handling ethylene oxide, the need for separate distillation of by-products, and inefficiencies in energy and resource usage, particularly in the separation of ammonia and hydrogen from reaction effluents.
Innovation Solution
A process involving the reaction of MEG with ammonia in the presence of hydrogen and a heterogeneous catalyst, followed by a redesigned ammonia separation method that includes condensation and scrubbing with MEG to enrich ammonia and hydrogen, allowing for efficient separation and reuse of resources.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If MEG is reacted with ammonia in the presence of ethylene oxide to produce EDA, then the reaction can proceed, but the selectivity decreases and byproducts such as diethanolamine and triethanolamine are formed
Solution Approach 1:
The patent removes ethylene oxide from the reaction system and replaces it with MEG as the sole carbon source. This extraction of the problematic intermediate eliminates the formation of higher ethanolamine byproducts while maintaining EDA production through direct amination of MEG.
Solution Approach 2:
The patent changes the reaction parameters by using a specific catalyst system (copper-containing catalyst) and controlling temperature (150-350°C) and pressure (3-30 bar) to achieve high selectivity for EDA from MEG without forming significant amounts of byproducts.
2Reliability
If ethylene oxide is handled in the production process, then the reaction can proceed, but safety risks increase due to flammability and explosion hazards
Solution Approach 1:
The patent extracts ethylene oxide from the process entirely, using MEG instead as the reactant. This eliminates the safety hazards associated with handling and storing ethylene oxide while maintaining the ability to produce EDA through alternative reaction pathways.
3Productivity
If MEA is produced by reacting ethylene oxide with ammonia, then the reaction proceeds, but additional distillation steps are required to separate byproducts
Solution Approach 1:
The patent removes the intermediate MEA production step and the associated distillation requirements by directly converting MEG to EDA in a single reaction step, thereby simplifying the overall process flow and reducing equipment complexity.
4Reliability
If conventional ammonia and hydrogen separation methods are used, then separation can be achieved, but energy consumption increases
Solution Approach 1:
The patent employs a scrubbing system where the reaction effluent itself is used to absorb and separate ammonia and hydrogen through condensation and washing steps, eliminating the need for energy-intensive conventional separation methods and enabling resource reuse within the process.
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 enhances resource efficiency by preheating MEG and reducing energy consumption, enabling the use of MEG without fiber quality and minimizing the need for further purification of washing liquids, while achieving high selectivity and purity of EDA and other ethylene amines.
Implementation Method 1
Passing the gaseous phase from stage 2-1) over one or more condensers, yielding one or more liquid phases enriched with ammonia and a gaseous phase enriched with hydrogen
Implementation Method 2
Contacting the gaseous phase from stage 2-2) with MEG, yielding a liquid phase containing MEG and ammonia and a gaseous phase containing hydrogen and optionally ammonia
Implementation Method 3
Reaction of MEG with ammonia in the presence of hydrogen and an amination catalyst
Data Source
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AI summary
The invention relates to a method for producing ethyleneamines and/or alkanolamines, having the following steps: 1) reacting MEG with ammonia in the presence of hydrogen and an amination catalyst; and 2) separating hydrogen and ammonia from the reaction product from stage 1. The invention is characterized in that the separation of hydrogen and ammonia carried out in stage 2 has the steps of: 2-1) separating the reaction product from stage 1 into a gaseous phase, which contains ammonia and hydrogen, and a liquid phase, which contains ethyleneamines and/or alkanolamines, 2-2) passing the gaseous phase from stage 2-1) over one or more condensers, wherein one or more liquid phases are obtained in which ammonia is enriched, and a gaseous phase is obtained in which hydrogen is enriched, and 2-3) bringing the gaseous phase from stage 2-2) into contact with MEG such that a liquid phase containing MEG and ammonia is obtained and a gaseous phase containing hydrogen and optionally ammonia is obtained.