Quantifying Brønsted Acid Sites in Aluminum Chloride Catalysts
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Solution Overview
Problem
Current methods for quantifying Brønsted acid sites in aluminum chloride-containing catalysts are challenging, especially in fresh and regenerated ionic liquids, as existing techniques are destructive or provide limited information due to interference from Lewis acid sites, and there is a need for a non-destructive method to control acid levels in hydrocarbon conversion processes.
Innovation Solution
A method involving the use of silane or borane compounds to react with Brønsted acid sites in aluminum chloride-containing catalysts, forming silyl or boryl compounds that can be measured in the hydrocarbon phase, allowing for the determination of Brønsted acid site quantities without interfering with Lewis acid sites, and enabling the regeneration and reuse of catalysts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If existing quantification methods are used for Brønsted acid sites, then measurement can be performed, but the methods are destructive or provide limited information due to interference from Lewis acid sites
Solution Approach 1:
The patent uses silane or borane compounds as intermediary reagents that selectively react with Brønsted acid sites to form measurable silyl or boryl compounds. These intermediaries enable indirect quantification without direct measurement of the acid sites themselves, avoiding interference from Lewis acid sites and preventing destruction of the catalyst structure
Solution Approach 2:
The patent replaces direct physical/chemical measurement methods with a chemical transformation approach. Instead of directly measuring Brønsted acid sites (which causes destruction or interference), the method transforms the acid sites into measurable silyl/boryl compounds through selective chemical reaction, substituting direct measurement with indirect quantification
2Productivity
If sulfuric acid or hydrofluoric acid is used as catalyst, then alkylation reaction can be performed, but environmental hazards and corrosiveness require extensive environmental controls
Solution Approach 1:
The patent changes the chemical parameters of the catalyst system by replacing traditional strong mineral acids (sulfuric acid, hydrofluoric acid) with ionic liquids containing aluminum chloride. This parameter change maintains the catalytic activity for alkylation reactions while eliminating the severe environmental hazards and corrosiveness associated with the traditional acids
Solution Approach 2:
The patent employs ionic liquids as composite catalyst systems that combine the beneficial properties of liquid state catalysts with controlled acidity. These ionic liquid-based catalysts provide the necessary catalytic function for alkylation while being environmentally friendlier and less corrosive than traditional mineral acids
3Object-affected harmful factors
If ionic liquid catalyst is used to replace sulfuric acid and hydrofluoric acid, then environmental friendliness is improved, but conjunct polymer forms complexes with the catalyst causing loss of effectiveness over time
Solution Approach 1:
The patent implements a catalyst regeneration strategy where the ionic liquid catalyst, after deactivation due to conjunct polymer complexation, can be regenerated to restore its effectiveness. This allows the catalyst to be reused multiple times, extending its operational duration and maintaining environmental friendliness throughout the process
4Productivity
If conjunct polymer is present in the catalyst, then byproduct of reaction is formed, but the catalyst loses effectiveness and must be replaced or regenerated
Solution Approach 1:
The patent employs a two-phase system where conjunct polymer is extracted from the ionic liquid catalyst phase into a separate hydrocarbon phase. This extraction removes the deactivating polymer complexes from the catalyst, restoring its effectiveness and allowing continued use without replacement
Solution Approach 2:
The patent utilizes phase separation between the ionic liquid catalyst phase and the hydrocarbon phase containing conjunct polymer. By exploiting the immiscibility and phase transition behavior of these components, the catalyst can be separated from deactivated polymer complexes, maintaining catalyst activity and enabling continuous operation
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 allows for accurate, non-destructive quantification of Brønsted acid sites in both fresh and spent catalysts, enabling effective acid level control in continuous processes and catalyst regeneration, thereby improving the efficiency and longevity of aluminum chloride-containing catalysts in hydrocarbon conversion processes.
Implementation Method 1
the Brønsted acid sites in the aluminum chloride-containing catalyst reacting with the at least one silane or borane compound
Implementation Method 2
resulting in a catalyst phase and a hydrocarbon phase comprising at least one silyl or boryl compound
Data Source
AI summary
A method of quantifying an amount of Brønsted acid sites in an aluminum chloride-containing catalyst is described. The method involves adding a known amount of at least one silane or borane compound to the aluminum chloride-containing catalyst being analyzed. The Brønsted acid sites in the aluminum chloride-containing catalyst react with the silane or borane compound to form a silyl boryl compound, resulting in a catalyst phase and a hydrocarbon phase which contains the silyl or boryl compound. The amount of silyl or boryl compound in the hydrocarbon phase is measured. From the measured amount of silyl or boryl compound formed, the amount of Brønsted acid sites can be determined.