Two-Step Alkyleneurea Conversion to Amines
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Solution Overview
Problem
Existing processes for converting cyclic alkyleneureas into alkyleneamines are inefficient, requiring large excesses of strong inorganic bases, leading to low product selectivities, salt formation, corrosion issues, and decreased storage stability due to the use of caustic bases.
Innovation Solution
A two-step process involving the reaction of cyclic alkyleneureas with water to remove CO2, followed by the addition of an inorganic base to convert remaining alkyleneureas into alkyleneamines, reducing the amount of inorganic base used and minimizing salt formation and corrosion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If large excesses of strong inorganic bases are used to convert cyclic alkyleneureas into alkyleneamines, then conversion efficiency is improved, but product selectivity deteriorates and salt formation increases
Solution Approach 1:
The conversion process is divided into two distinct stages: first, a controlled reaction with water to remove CO2 and achieve partial conversion; second, a targeted reaction with inorganic base to complete the conversion of remaining alkyleneureas. This segmentation allows each stage to be optimized independently, preventing excessive base usage and improving product selectivity while maintaining high overall conversion efficiency.
Solution Approach 2:
The water treatment step is performed as a preliminary action before adding the inorganic base. This preliminary removal of CO2 and partial conversion of alkyleneureas creates more favorable conditions for the subsequent base reaction, reducing the amount of base needed and minimizing salt formation while maintaining high conversion efficiency.
2Productivity
If large excesses of strong inorganic bases are used to convert cyclic alkyleneureas into alkyleneamines, then conversion efficiency is improved, but salt formation increases
Solution Approach 1:
The two-stage process segments the conversion into a water treatment phase followed by a controlled base reaction phase. This prevents the need to use large excesses of base from the outset, thereby reducing salt formation while maintaining high conversion efficiency in the second stage.
Solution Approach 2:
The water treatment step serves as a preliminary action that removes CO2 and partially converts alkyleneureas before the base reaction. This preliminary action reduces the burden on the inorganic base, minimizing the amount needed and consequently reducing salt formation as a byproduct.
3Productivity
If strong inorganic bases are used to convert cyclic alkyleneureas into alkyleneamines, then conversion is achieved, but corrosion issues and decreased storage stability occur
Solution Approach 1:
The process is segmented into a water treatment stage followed by a controlled base reaction stage. This segmentation allows the base to be used more efficiently and in smaller amounts, reducing its corrosive impact on equipment and minimizing degradation of the stored amine products, thereby improving storage stability while maintaining conversion effectiveness.
Solution Approach 2:
The water treatment step acts as a preliminary action that prepares the reaction mixture by removing CO2 and partially converting alkyleneureas. This preliminary preparation reduces the aggressiveness and corrosiveness of the subsequent base reaction, protecting equipment and improving the storage stability of the final amine product.
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 achieves high conversion and yield of alkyleneamines with improved selectivity and reduced salt formation, while using less inorganic base, thus addressing the inefficiencies and stability issues of previous methods.
Implementation Method 1
converting cyclic alkyleneureas into their corresponding alkyleneamines by reacting cyclic alkyleneureas in the liquid phase with water with removal of CO2
Implementation Method 2
adding an inorganic base and reacting cyclic alkylene ureas remaining from the first step with the inorganic base to convert them partially or completely into their corresponding alkyleneamines
Data Source
AI summary
A process is provided for converting cyclic alkyleneureas into their corresponding alkyleneamines. The process includes, in a first step, converting cyclic alkyleneureas into their corresponding alkyleneamines by reacting cyclic alkyleneureas in the liquid phase with water with removal of CO2, so as to convert from about 5 mole % to about 95 mole % of alkyleneurea moieties in the feedstock to the corresponding amines. The process further includes, in a second step, adding an inorganic base and reacting cyclic alkylene ureas remaining from the first step with the inorganic base to convert them partially or completely into their corresponding alkyleneamines. Certain embodiments of the two-step process obtain a high conversion of cyclic alkyleneureas, while using substantially less strong inorganic base. Certain embodiments of the process process also show a higher selectivity to amines than prior art processes.