Deep Eutectic Solvent Extraction of Phenol and Pyridine From Naphthalene Oil
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Solution Overview
Problem
Existing methods for separating phenol and pyridine compounds from naphthalene oil are complex, corrosive, and environmentally harmful due to the use of strong acids and bases, leading to equipment corrosion and water pollution.
Innovation Solution
A stepwise extraction process using deep eutectic solvents (DES) with specific combinations of hydrogen bond donors and acceptors, combined with stripping and distillation, to selectively separate phenol and pyridine compounds, allowing for solvent and agent recycling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If strong acid and base solutions are used for extraction, then phenol and pyridine compounds can be separated, but equipment corrosion occurs and the process becomes complex
Solution Approach 1:
The patent changes the chemical parameters of the extraction system by replacing strong acid/base solutions with deep eutectic solvents formed from weak acid (oxalic acid) and weak base (tetrabutylammonium bromide). This parameter change maintains separation effectiveness while eliminating equipment corrosion and reducing environmental harm.
Solution Approach 2:
The patent introduces deep eutectic solvents as intermediary substances that mediate the extraction process. These DES act as a buffer between the phenol/pyridine compounds and the equipment, providing effective separation without the direct corrosive contact that would occur with strong acid/base solutions.
2Reliability
If strong acid and base solutions are used for extraction, then phenol and pyridine compounds can be separated, but the process complexity increases
Solution Approach 1:
By changing the chemical parameters from strong acid/base to deep eutectic solvents, the patent simplifies the neutralization and washing steps. The weak acid/base nature of DES eliminates the need for aggressive neutralization, reducing process complexity while maintaining separation effectiveness.
Solution Approach 2:
The patent extracts only the essential separation function using deep eutectic solvents, removing the unnecessary complexity of strong acid/base neutralization and extensive washing steps. This extraction approach isolates the core separation mechanism from the harmful and complex ancillary processes.
3Reliability
If strong acid and base solutions are used for extraction, then phenol and pyridine compounds can be separated, but energy consumption increases
Solution Approach 1:
The patent changes the thermal and chemical parameters by using deep eutectic solvents with lower neutralization heat requirements compared to strong acid/base systems. This parameter change reduces energy consumption during the neutralization and heating steps while maintaining effective separation.
4Reliability
If strong acid and base solutions are used for extraction, then phenol and pyridine compounds can be separated, but water pollution is caused
Solution Approach 1:
The patent changes the chemical composition parameters by replacing strong acid/base solutions with deep eutectic solvents composed of weak acid and weak base. This parameter change transforms the extraction system from one that generates harmful wastewater to one that produces environmentally benign waste that can be easily treated or recycled.
Solution Approach 2:
The patent converts potentially harmful strong acid/base waste streams into beneficial or neutral deep eutectic solvent waste. The weak acid/base components of DES can be easily neutralized or recycled, turning what would be a pollution problem into a sustainable solution.
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
The method achieves efficient, simple, and environmentally friendly separation of phenol and pyridine compounds with high selectivity and low energy consumption, enabling solvent and agent reuse.
Implementation Method 1
mixing the naphthalene oil, alkane and the deep eutectic solvents, and performing phase separation to obtain a heteroatom eutectic phase and a hydrocarbon raffinate phase
Implementation Method 2
the deep eutectic solvents are a mixture of at least one of tetraethylammonium chloride, tetrabutylammonium chloride, tetrabutylammonium bromide and tetrabutylphosphonium bromide, and at least one of a glycolic acid, an oxalic acid, a citric acid and a p-toluenesulfonic acid
Implementation Method 3
mixing the heteroatom eutectic phase with a first stripping agent, and performing phase separation to obtain a first stripping organic phase and a first stripping raffinate phase
Implementation Method 4
mixing the heteroatom mixture, alkane and a hydrogen bond acceptor extractant, and performing phase separation to obtain a phenol eutectic phase and a pyridine raffinate phase
Data Source
AI summary
A method for stepwise extraction of phenol and pyridine compounds in naphthalene oil by deep eutectic solvents includes: mixing the naphthalene oil with alkane and the deep eutectic solvents, and performing phase separation to obtain a eutectic extracting phase and a raffinate phase; mixing the extracting phase with a first stripping agent, and performing phase separation to obtain a first stripping phase and recyclable deep eutectic solvents; distilling the first stripping phase to obtain a heteroatom mixture; and mixing the heteroatom mixture with a hydrogen bond acceptor extractant and alkane, and performing phase separation to obtain a phenol-containing extracting phase and a pyridine-containing raffinate phase; and mixing the phenol-containing extracting phase with a second stripping agent, performing phase separation to obtain a phenol-dissolved stripping solution and the hydrogen bond acceptor, and distilling the second stripping solution or the pyridine-containing raffinate phase to obtain a phenol or a pyridine product.