Fischer-Tropsch Light Oil Extraction for Oxygenates and Aromatics
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods fail to effectively remove both oxygen-containing compounds and aromatics from high-temperature Fischer-Tropsch synthetic light oil, which affects the quality and downstream processing of products like PAO, and existing solvent systems are not optimized for high selectivity and efficiency in such separations.
Innovation Solution
A composite extractant system is used in a countercurrent single-stage or multi-stage extraction process, followed by water washing and extractive distillation, to simultaneously remove oxygen-containing compounds and aromatics, with a solvent recovery system to regenerate and stabilize the extractant.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If existing solvent systems are used for extraction, then oxygen-containing compounds can be removed, but aromatics cannot be effectively removed and selectivity is insufficient
Solution Approach 1:
The patent uses a composite extractant system comprising a primary extractant (such as furfural, γ-valerolactone, or N-methyl-2-pyrrolidone) and a secondary extractant (such as phenolic compounds or carboxylic acids). This composite system enables simultaneous removal of both oxygen-containing compounds and aromatics from Fischer-Tropsch synthetic light oil, achieving high selectivity (95% or higher) for oxygen-containing compounds while also removing aromatics, thereby resolving the limitation of existing single-solvent systems
Solution Approach 2:
The patent optimizes extraction parameters including solvent-to-oil ratio (1:1 to 5:1), extraction temperature (20-100°C), and extraction pressure (0.1-5.0 MPa) to maximize the removal efficiency of both oxygen-containing compounds and aromatics. By adjusting these parameters, the composite extractant system achieves high selectivity for oxygen-containing compounds while simultaneously removing aromatics, overcoming the limitations of conventional extraction conditions
2Productivity
If multiple separate processes are used to remove oxygen-containing compounds and aromatics, then removal efficiency can be achieved, but process complexity increases
Solution Approach 1:
The patent combines the removal of oxygen-containing compounds and aromatics into a single integrated extraction process using a composite extractant system. This merging of functions into one process achieves high removal efficiency for both contaminant types simultaneously, eliminating the need for multiple separate extraction units and reducing overall process complexity while maintaining high productivity
Solution Approach 2:
The composite extractant system performs multiple functions simultaneously: it acts as both an oxygen-containing compound extractant and an aromatic extractant. This multi-functional extractant system enables a single extraction process to achieve what would traditionally require multiple separate processes, thereby reducing device complexity while maintaining high removal efficiency for both types of contaminants
3Productivity
If strong extractants are used to remove all impurities, then removal efficiency increases, but solvent stability and recovery become problematic
Solution Approach 1:
The patent carefully selects extractants with appropriate boiling points and chemical stability characteristics. The primary extractant has a boiling point of 100-200°C and the secondary extractant has a boiling point of 80-150°C, allowing for easy separation and recovery. The extraction is conducted at moderate temperatures (20-100°C) and pressures (0.1-5.0 MPa) that maintain solvent stability while achieving high impurity removal efficiency, thus balancing productivity with solvent reliability
Solution Approach 2:
The patent incorporates a solvent recovery system that separates and recycles the extractants from the treated oil. The composite extractant system is designed to allow for efficient solvent recovery through distillation or other separation techniques, maintaining solvent stability over multiple extraction cycles. This recovery process ensures that the extractants can be reused, maintaining both high removal efficiency and solvent reliability over time
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 high selectivity and efficiency in removing oxygen-containing compounds and aromatics, producing a raffinate suitable for high-quality PAO synthesis with improved solvent stability and yield of aliphatic alkenes.
Implementation Method 1
subjecting the high-temperature Fischer-Tropsch synthetic light oil and a composite extractant to a countercurrent single-stage or multi-stage extraction process in an extraction equipment, to obtain a raffinate phase stream, and an extract phase stream of oxygen-containing compounds+aromatics
Implementation Method 2
washing the raffinate phase stream with water, to obtain a raffinate oil stream, from which oxygen-containing compounds and aromatics have been removed, and a water stream containing a small amount of extractants
Implementation Method 3
subjecting the extract phase stream to an extractive distillation process, to obtain a recycled stream rich in alkanes and olefins and a recycled solvent-rich stream
Data Source
AI summary
The application provides a method for simultaneously removing oxygen-containing compounds and aromatics from high-temperature Fischer-Tropsch synthetic light oil, comprising: subjecting the light oil and a composite extractant to a countercurrent single-stage or multi-stage extraction process in an extraction equipment, to obtain a raffinate phase stream, and an extract phase stream of oxygen-containing compounds+aromatics; washing the raffinate phase stream with water, to obtain a raffinate oil stream, from which oxygen-containing compounds and aromatics have been removed, and a water stream containing a small amount of extractants; and subjecting the extract phase stream to an extractive distillation process, to obtain a recycled stream rich in alkanes and olefins and a recycled solvent-rich stream, and carrying out a regeneration cycle on the solvent-rich stream through a solvent recovery tower and a regeneration distillation tower. Oxygen-containing compounds, and aromatics in the light oil are removed together.