Metallocene Catalyzed Sulfolene Synthesis Polymer Control
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Solution Overview
Problem
Existing methods for manufacturing sulfolene and sulfolane compounds face issues such as polymer generation blocking equipment and prolonged hydrogenation reaction times due to residual sulfur dioxide, with existing inhibitors and catalysts not consistently effective.
Innovation Solution
A method involving the reaction of a conjugated diene compound with sulfur dioxide in the presence of a metallocene compound, followed by hydrogenation with a catalyst, using a stabilizer and alkali agent to control polymer generation and catalyst activity, ensuring smooth hydrogenation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If conventional polymerization inhibitors (4-t-butylcatechol or dimethylamine) are used in the reaction of conjugated diene with sulfur dioxide, then polymer generation is inhibited, but the hydrogenation catalyst activity is inhibited leading to prolonged reaction time
Solution Approach 1:
The patent changes the chemical parameter of the polymerization inhibitor from conventional organic inhibitors (4-t-butylcatechol or dimethylamine) to an inorganic base (alkali metal hydroxide, alkaline earth metal hydroxide, or ammonium hydroxide). This parameter change resolves the contradiction because the inorganic base effectively suppresses polymerization through neutralization of acidic byproducts without the catalyst-inhibiting side effects of organic inhibitors, thereby maintaining fast hydrogenation reaction rates.
2Reliability
If residual sulfur dioxide is present in the reaction system before hydrogenation, then the hydrogenation catalyst activity is inhibited, but removing sulfur dioxide requires additional processing steps
Solution Approach 1:
The patent extracts and removes sulfur dioxide from the reaction system before the hydrogenation step through purging or distillation. This extraction of the harmful component (sulfur dioxide) protects the hydrogenation catalyst from inhibition while the simplified workup procedure minimizes additional processing complexity.
Solution Approach 2:
The patent performs preliminary removal of sulfur dioxide from the reaction mixture before initiating the hydrogenation reaction. This preliminary action prevents catalyst inhibition from occurring in the first place, ensuring high catalyst activity throughout the hydrogenation process without requiring complex in-situ removal systems.
3Loss of time
If a large amount of additional catalyst is used to compensate for inhibited catalyst activity, then hydrogenation reaction time is reduced, but production cost increases
Solution Approach 1:
The patent changes the parameter of the polymerization inhibition method to use inorganic bases instead of organic inhibitors. This parameter change eliminates the need for additional catalyst quantities because the inorganic base does not interfere with hydrogenation catalyst activity, thereby maintaining both short reaction times and economical catalyst usage.
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 method effectively inhibits polymer generation, controls hydrogenation catalyst activity, and reduces reaction time, resulting in improved yields and equipment efficiency.
Implementation Method 1
reacting a conjugated diene compound represented by a formula (1) with sulfur dioxide in the presence of a metallocene compound
Implementation Method 2
hydrogenating the sulfolene compound in the presence of a hydrogenation catalyst
Implementation Method 3
hydrogenating the sulfolene compound in the presence of a hydrogenation catalyst
Data Source
AI summary
An object of the present invention is to provide a method for manufacturing a sulfolene compound, the method being capable of inhibiting generation of polymers. Another object of the present invention is to provide a method for manufacturing a sulfolane compound, the method being capable of controlling inhibition of hydrogenation catalyst activity and smoothly hydrogenating a sulfolene compound.The present invention is a method for manufacturing a sulfolene compound represented by a formula (2), which comprises the step of reacting a conjugated diene compound represented by a formula (1) with sulfur dioxide in the presence of a metallocene compound:in the formula (1), R1 to R6 each independently represents a hydrogen atom or a C1 to C6 alkyl group,in the formula (2), R1 to R6 represent the same groups represented by R1 to R6 in the formula (1).