Catalyst Composition for Reductive Amination Selectivity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The reductive amination of diethanolamine (DEA) with ammonia often results in high levels of non-piperazine (PIP) and non-aminoethylethanolamine (AEEA) products, which are of lesser economic value and less useful for further processing, due to the inefficiencies in existing catalyst systems.
Innovation Solution
A catalyst composition featuring an acidic mixed metal oxide support with transitional alumina and a combination of catalytic metals such as cobalt, nickel, or copper, and noble transition metals like ruthenium or rhenium is used to promote the formation of PIP and AEEA, minimizing the production of unwanted byproducts at moderate temperatures and ammonia/DEA ratios.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional Ni-MgO catalyst is used for reductive amination of DEA, then PIP and AEEA can be produced, but significant amounts of non-PIP and non-AEEA products are formed (27% total)
Solution Approach 1:
The invention changes the chemical composition parameters of the catalyst by using a mixed metal oxide support (alumina-silica or alumina-zirconia) with specific surface area and pore volume characteristics, combined with copper and ruthenium metals in optimized ratios. This parameter optimization enables high selectivity toward PIP and AEEA while minimizing formation of unwanted byproducts.
Solution Approach 2:
The invention employs a composite catalyst system consisting of copper and ruthenium metals supported on mixed metal oxide (alumina-silica or alumina-zirconia). This composite structure synergistically combines the properties of different materials to achieve high activity and selectivity for reductive amination, significantly reducing non-PIP and non-AEEA product formation compared to conventional single-metal catalysts.
2Productivity
If high temperatures (225°C) are used for reductive amination, then DEA conversion can be achieved, but catalyst activity is compromised and non-PIP/AEEA products increase
Solution Approach 1:
The invention optimizes the catalyst's physical and chemical parameters, including using mixed metal oxide supports with controlled surface area (200-400 m²/g) and pore volume (0.3-0.5 cm³/g), and optimizing metal loading ratios. These parameter changes enable the catalyst to achieve high DEA conversion rates at lower temperatures (150-200°C), improving productivity while maintaining catalyst stability and reducing unwanted byproduct formation.
3Productivity
If moderate ammonia/DEA ratios (10:1) are used, then process efficiency is improved, but selectivity towards PIP and AEEA decreases with conventional catalysts
Solution Approach 1:
The composite catalyst system of copper and ruthenium on mixed metal oxide support exhibits enhanced selectivity toward PIP and AEEA even at moderate ammonia/DEA ratios (10:1). The synergistic interaction between the bimetallic catalyst and the acidic support creates active sites that favor the formation of desired products, maintaining high selectivity while improving process efficiency through reduced ammonia consumption.
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 significantly improves the selectivity for PIP and AEEA, achieving high yields while maintaining catalyst activity at lower temperatures, allowing for the recycling of AEEA and utilizing existing industrial supplies of DEA, thus optimizing product composition and process efficiency.
Implementation Method 1
The reductive amination of DEA with ammonia is performed in the presence of a catalyst composition to produce a product composition that includes PIP and AEEA
Data Source
AI summary
The invention provides a method for the reductive amination of diethanolamine to form a product composition that includes piperazine (PIP) and aminoethylethanolamine (AEEA). A catalyst with a transitional alumina/second metal oxide support and a mixture of catalytic metals is used for the reaction which results in low levels of non-PIP and non-AEEA side products.