Ruthenium Catalyst Stability in Cycloolefin Production
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Solution Overview
Problem
The long-term use of ruthenium catalysts in partial hydrogenation reactions of monocyclic aromatic hydrocarbons leads to reduced catalyst activity and selectivity, due to factors such as sintering, poisoning, and interaction with hydrogen.
Innovation Solution
Controlling the nitrogen concentration in the aqueous zinc sulfate solution to a range of 0.5 to 3000 mg/L, and adjusting the acetic acid concentration to 1 × 10^-3 to 100 mg/L, helps to maintain high catalytic activity and selectivity of cycloolefin production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If the ruthenium catalyst is used for long-term production, then the production continuity is improved, but the catalyst activity and selectivity are reduced due to sintering, poisoning, and hydrogen interaction
Solution Approach 1:
The patent applies parameter changes by controlling the nitrogen concentration in the aqueous zinc sulfate solution within a specific range (0.5 to 3000 mg/L) and adjusting the acetic acid concentration (1 × 10^-3 to 100 mg/L). These parameter adjustments optimize the reaction environment to maintain catalyst activity and selectivity over extended periods, resolving the contradiction between catalyst lifespan and catalytic performance
Solution Approach 2:
The patent introduces an intermediary system involving aqueous zinc sulfate solution with controlled nitrogen and acetic acid concentrations. This intermediary medium acts as a buffer that protects the ruthenium catalyst from deactivation mechanisms (sintering, poisoning, hydrogen interaction) while allowing long-term operation, thus maintaining both catalyst lifespan and activity
2Reliability
If the catalyst is replaced frequently to maintain high activity, then the catalytic performance is improved, but the production efficiency and operational continuity are reduced
Solution Approach 1:
By optimizing the nitrogen concentration (0.5 to 3000 mg/L) and acetic acid concentration (1 × 10^-3 to 100 mg/L) parameters in the reaction medium, the patent extends the operational life of the catalyst while maintaining high activity and selectivity, thereby eliminating the need for frequent replacements and improving production efficiency
Solution Approach 2:
The patent enables continuous operation of the catalyst over extended periods by creating a protected reaction environment through controlled nitrogen and acetic acid concentrations. This continuity of useful action prevents catalyst deactivation, allowing uninterrupted production without sacrificing catalytic performance
3Reliability
If the nitrogen concentration in the aqueous zinc sulfate solution is increased, then the catalyst protection is improved, but the production cost and process complexity increase
Solution Approach 1:
The patent establishes a wide acceptable range for nitrogen concentration (0.5 to 3000 mg/L) and acetic acid concentration (1 × 10^-3 to 100 mg/L), which provides flexibility in process control. This parameter optimization achieves catalyst protection without requiring overly complex control systems, as the broad ranges allow for easier maintenance within specification limits
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 enables stable and efficient production of cycloolefins by suppressing reductions in catalytic activity and selectivity, thereby extending the catalyst's lifespan and reducing the frequency of catalyst replacement.
Implementation Method 1
partial hydrogenation reaction of a monocyclic aromatic hydrocarbon with hydrogen using a ruthenium catalyst
Implementation Method 2
partial hydrogenation reaction of a monocyclic aromatic hydrocarbon with hydrogen
Implementation Method 3
aqueous zinc sulfate solution contains dimethylamine, and the aqueous zinc sulfate solution has a nitrogen concentration of 0.5 to 3000 mg/L
Data Source
AI summary
Provided is a method for producing a cycloolefin, comprising subjecting a monocyclic aromatic hydrocarbon to partial hydrogenation reaction with hydrogen in an aqueous zinc sulfate solution in the presence of a ruthenium catalyst, wherein the aqueous zinc sulfate solution contains dimethylamine, and the partial hydrogenation reaction is performed with a nitrogen concentration in the aqueous zinc sulfate solution adjusted to 0.5 to 3000 mg/L or an acetic acid concentration in the aqueous zinc sulfate solution adjusted to 1 × 10-3 to 100 mg/L.