Heterogeneous Catalyst Geometry for Ethyleneamine Selectivity
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Solution Overview
Problem
Existing processes for producing ethylene amines, such as diethylenetriamine and ethylenediamine, suffer from low selectivity and the need for catalyst separation, with by-products like piperazine and aminoethylethanolamine being formed in significant quantities, limiting their yield and efficiency.
Innovation Solution
A process involving the reaction of monoethanolamine with ammonia using a heterogeneous transition metal catalyst, specifically with oxygen-comprising compounds of aluminum, copper, nickel, and cobalt, in the form of small shaped catalyst bodies, to enhance the yield and selectivity of ethylenediamine and diethylenetriamine, while minimizing piperazine formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If suspension catalysis is used for amination of monoethanolamine with ammonia, then the reaction can proceed, but the catalyst must be separated from the product and selectivities need improvement
Solution Approach 1:
The patent changes the physical state parameter of the catalyst from suspension (liquid/colloidal) to heterogeneous solid catalyst bodies with specific size ranges (0.1-10 mm diameter). This parameter change eliminates the need for complex separation processes while maintaining catalytic activity and improving selectivity for ethylenediamine production.
Solution Approach 2:
The patent employs heterogeneous catalyst bodies that can be easily separated from the product stream and reused, replacing the need for complex separation infrastructure. The catalyst bodies maintain their activity over extended periods, eliminating the need for continuous catalyst replacement or complex recovery systems.
2Manufacturing precision
If amination of monoethanolamine with ammonia is performed to suppress higher ethylene amines, then ethylene diamine yield increases, but aminoethylethanolamine and piperazine are formed as by-products
Solution Approach 1:
The patent applies local quality by using catalyst bodies with specific size ranges (0.1-10 mm diameter) that provide optimized surface area and pore structure. This local structural quality enhances selectivity for the desired ethylenediamine product while minimizing formation of unwanted by-products like aminoethylethanolamine and piperazine through controlled active site distribution.
Solution Approach 2:
The patent employs composite catalyst materials combining multiple components with complementary properties. The heterogeneous catalyst bodies integrate active catalytic sites with supportive matrix materials, creating a composite structure that improves selectivity for ethylenediamine while suppressing by-product formation through synergistic effects of the composite material components.
3Productivity
If conventional catalysts are used for ethylene amine production, then the process can operate, but space-time yields are insufficient
Solution Approach 1:
The patent transitions from conventional bulk or powdered catalysts to heterogeneous catalyst bodies with defined geometric dimensions (0.1-10 mm diameter). This dimensional change optimizes the surface area-to-volume ratio, enhancing mass transfer and active site accessibility, thereby significantly improving space-time yield while maintaining high catalyst activity.
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 yields and selectivities for ethylenediamine and diethylenetriamine, with piperazine production limited to below 20% by weight, and maintains catalyst activity through controlled hydrogen addition, resulting in increased space-time yields and reduced by-product formation.
Implementation Method 1
reaction of monoethanolamine with ammonia in the presence of a heterogeneous transition metal catalyst
Implementation Method 2
maintains catalyst activity through controlled hydrogen addition
Data Source
AI summary
Processes comprising: providing a starting material comprising monoethanolamine; and reacting the starting material with ammonia in the presence of a heterogeneous transition metal catalyst to form a reaction product comprising one or more ethylene amines; wherein the catalyst comprises a catalytically active composition, which prior to treatment with hydrogen, comprises a mixture of oxygen-containing compounds of aluminum, copper, nickel and cobalt; and wherein the catalyst is present as one or more shaped catalyst particles selected from spheres, extrudates, pellets and other geometries, wherein the sphere or extrudate has a diameter of <3 mm, the pellet has a height of <3 mm, and the other geometries have an equivalent diameter L=1/a′ of <0.70 mm, where a′ is the external surface area per unit volume (mms2/mmp3), as defined by a ′ = A p V p where Ap is the external surface area of the catalyst particle (mms2) and Vp is the volume of the catalyst particle (mmp3).