Nitrile Hydrogenation Reactor Cross-Sectional Loading Optimization
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Solution Overview
Problem
Existing processes for hydrogenating nitrile compounds to amino compounds are complex and result in low yields and selectivities, with issues such as hydrogen cyanide (HCN) elimination reducing IPDA yield and deactivating catalysts, and high cross-sectional loading requiring complex reaction setups.
Innovation Solution
A process with a cross-sectional loading of the reactor of less than or equal to 4.0 kg/m²*s, using a mixture of 2,4,4-trimethylhexamethylenedinitrile and 2,2,4-trimethylhexamethylenedinitrile, and isophoronenitrile or isophoronenitrilimine hydrogenated in the presence of ammonia and a catalyst, preferably in a continuous trickle-bed reactor with reduced circulation ratios, to produce isophoronediamine.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high cross-sectional loading is used to achieve high productivity, then productivity increases, but device complexity increases due to complex reaction setups and high circulating flow rates
Solution Approach 1:
The patent changes the operating parameter of cross-sectional loading from high values (conventional) to low values (≤4.0 kg/m²*s), enabling the use of simple trickle-bed reactor designs while maintaining high productivity through optimized catalyst composition and reaction conditions
2Productivity
If conventional hydrogenation processes are used, then amino compounds are produced, but HCN elimination reduces yield and deactivates catalysts
Solution Approach 1:
The patent converts the harmful HCN elimination side reaction into a beneficial process by using the generated HCN in situ for in situ imination of ketone groups, transforming a yield-reducing and catalyst-deactivating side reaction into a useful reaction pathway that produces diamine products
Solution Approach 2:
The patent applies preliminary action by pre-activating the catalyst with alkali metals (K, Na, Li) before the main hydrogenation reaction, which prepares the catalyst surface to promote imination reactions and suppress HCN elimination, thereby protecting against catalyst deactivation before it occurs
3Productivity
If imination catalysts are used to accelerate IPNI formation, then IPDA yield increases, but byproducts such as amino alcohol and bicyclic compounds are formed
Solution Approach 1:
The patent applies local quality by creating different chemical environments on different parts of the catalyst surface through alkali metal promotion, with specific regions favoring imination reactions while other regions suppress unwanted side reactions like amino alcohol and bicyclic compound 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 simplifies the reactor design, achieves high yields and selectivities for isophoronediamine, suppresses by-products, and extends catalyst service life by minimizing HCN formation, allowing for efficient and high-yield production of amino compounds.
Implementation Method 1
Nitrile groups can be converted into aminomethyl groups via hydrogenation. Optionally, further reducible functional groups, such as imino groups, can also be hydrogenated in the process.
Implementation Method 2
In the presence of ammonia, ketonitriles, in particular, can be converted into amino compounds (with at least two amino groups) via aminative hydrogenation
Data Source
AI summary
The present invention relates to a process for the hydrogenation of nitrile compounds to amino compounds, wherein the cross-sectional load of the reactor during hydrogenation is less than or equal to 4.0 kg/m2*s with reference to the liquid phase.