Cyclododecatriene Production via Nickel Catalyst Optimization
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Solution Overview
Problem
Existing methods for producing cyclododecatriene (CDT) face challenges such as low yields, high polymeric by-products, long reaction times, and the need for polar solvents, making them unsuitable for industrial applications, particularly in continuous processes using nickel or titanium catalysts.
Innovation Solution
A process involving transition metal complexes of nickel and/or titanium, with the addition of a compound containing an element from main group 5 of the periodic table and a suitable solvent system, operating at controlled temperatures below 140°C for nickel and 80°C for titanium, to achieve high selectivity and yield of CDT, while minimizing polymeric by-products and chlorocyclododecatriene.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional catalyst systems (titanium tetrachloride, 4,4'-dichlorobenzophenone, dimethyl sulfoxide, diethylaluminum sesquichloride) are used at 40°C, then CDT can be produced, but the reaction requires high-boiling DMSO additive which must be removed again, increasing process complexity
Solution Approach 1:
The patent removes the problematic DMSO additive from the catalyst system and replaces it with dimethyl carbonate, which does not require subsequent removal steps. This extraction of the harmful component resolves the contradiction between reliable CDT production and process complexity.
Solution Approach 2:
The patent changes the chemical parameter of the additive from dimethyl sulfoxide (high-boiling, requires removal) to dimethyl carbonate (lower boiling, easier to handle). This parameter change eliminates the need for additional removal steps while maintaining catalytic activity.
2Reliability
If titanium catalyst system with Ti(OR)4 and AlR'X2 is used, then CDT formation occurs, but the reaction requires very long reaction times of 18 hours, making it unsuitable for industrial applications
Solution Approach 1:
The patent modifies the catalyst system parameters by using titanium tetrachloride with dimethyl carbonate and diethylaluminum sesquichloride, which significantly accelerates the reaction rate compared to Ti(OR)4 systems. The reaction time is reduced from 18 hours to a much shorter duration, enabling industrial applicability while maintaining CDT formation capability.
3Productivity
If water is added to accelerate catalytic trimerization of butadiene, then reaction rate increases, but the amount of undesired by-products becomes too high, with CDT yields of 83% and 62% being insufficient for industrial use
Solution Approach 1:
The patent introduces dimethyl carbonate as an intermediary substance that mediates between the catalyst components and butadiene. This intermediary enables accelerated reaction rates without the formation of excessive by-products, achieving both high productivity and high CDT yield (>90%) suitable for industrial use.
Solution Approach 2:
The patent changes the chemical environment by using dimethyl carbonate instead of water as the additive. This parameter change maintains the beneficial effect of reaction rate acceleration while eliminating the harmful effect of high by-product formation and low CDT yield.
4Productivity
If continuous process is used with homogeneous catalysts, then production efficiency increases, but catalyst concentration decreases over time requiring constant replacement with fresh catalyst
Solution Approach 1:
The patent employs a catalyst system that maintains stable activity over extended periods in continuous operation. The catalyst automatically regenerates or maintains its active form without requiring external intervention for replacement, enabling long-term continuous production with constant catalyst concentration and high productivity.
5Reliability
If polar solvents are used for catalyst decomposition, then catalyst destruction is achieved, but considerable technical effort and economic disadvantages are associated with the process
Solution Approach 1:
The patent uses dimethyl carbonate, which can be easily decomposed and removed, replacing the need for complex polar solvent systems. The additive serves its catalytic function and then can be simply eliminated from the product, reducing both technical effort and economic cost while maintaining catalyst decomposition effectiveness.
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 enables high selectivity and yield of CDT with reduced polymeric by-products and chlorocyclododecatriene, optimizing the ratio of CDT to higher oligomers, and allowing for the isolation of cyclooctadiene and vinylcyclohexene, suitable for industrial-scale production.
Implementation Method 1
a process for the preparation of cyclododecatriene (CDT) with high yields and a small amount of polymeric by-products using a catalyst system containing nickel and/or titanium
Data Source
AI summary
The present invention describes the production of cyclododecatriene in a continuous or batch process by trimerization of butadiene in the presence of a catalyst system and a solvent. The crude cyclododecatriene obtained can be isolated by distillation. The cyclooctadiene formed as a byproduct can also be isolated from the crude product.