Aromatic Hydrocarbon Separation via Segmented Distillation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional processes for producing benzene and styrene from raw pyrolysis gasoline require separate steps, leading to excessive energy consumption and unnecessary process costs due to repeated separation and mixing of hydrocarbons.
Innovation Solution
A method that simultaneously produces benzene, xylene, and styrene by separating raw material streams into C6−, C7, and C8+ hydrocarbons, using a C6 separation column, hydrodealkylation reaction unit, and extractive distillation columns to streamline the process and reduce energy usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If raw material is supplied to gasoline hydrogenation without separating C7+ hydrocarbons, then benzene production is achieved, but hydrogen consumption increases due to increased flow rate
Solution Approach 1:
The patent segments the hydrocarbon stream by carbon number using separation columns (C6 separation column, C7 separation column, C8 separation column) before processing. This allows C6− hydrocarbons to be sent to gasoline hydrogenation while C7+ hydrocarbons are directed to hydrodealkylation, preventing unnecessary hydrogen consumption from processing heavier fractions that don't require hydrogenation for benzene production.
Solution Approach 2:
The patent extracts and removes C7+ hydrocarbons from the raw material stream before the gasoline hydrogenation step using separation columns. This extraction prevents these heavier hydrocarbons from increasing the flow rate to the hydrogenation unit, thereby reducing hydrogen consumption while maintaining benzene production efficiency.
2Manufacturing precision
If C7+ hydrocarbons are subjected to hydrodealkylation again after gasoline hydrogenation, then benzene separation is improved, but energy consumption doubles
Solution Approach 1:
The patent performs preliminary separation of C7+ hydrocarbons from the raw material stream using separation columns before the gasoline hydrogenation step. This preliminary action prevents the need for subsequent hydrodealkylation of these fractions, eliminating the energy-consuming step while maintaining effective benzene separation through the structured separation columns.
Solution Approach 2:
The patent extracts C7+ hydrocarbons from the stream before gasoline hydrogenation, removing them from the process flow. This extraction eliminates the need for repeated hydrodealkylation processing, thereby reducing energy consumption while maintaining benzene production and separation efficiency through the separation column system.
3Manufacturing precision
If prefraction process is performed before extractive distillation for styrene production, then styrene separation is improved, but process complexity and energy consumption increase
Solution Approach 1:
The patent merges the styrene production process with the existing benzene production separation columns. The C6 separation column, C7 separation column, and C8 separation column that were used for benzene production are also utilized for styrene separation, eliminating the need for separate prefraction equipment and reducing overall process complexity while maintaining styrene separation efficiency.
Solution Approach 2:
The separation columns designed for benzene production are made multi-functional by using them for both benzene and styrene separation. The C6, C7, and C8 separation columns handle multiple separation tasks, reducing the total number of equipment pieces needed and simplifying the overall process architecture while achieving effective styrene separation.
4Adaptability or versatility
If C7− hydrocarbons and C8 hydrocarbon are introduced into benzene production process, then material utilization is improved, but repeated separation steps increase energy consumption
Solution Approach 1:
The patent segments the hydrocarbon fractions by carbon number using dedicated separation columns (C6 separation column for C6−, C7 separation column for C7, C8 separation column for C8+). This segmentation allows each fraction to be processed appropriately without being mixed with others, eliminating repeated separation steps and reducing energy consumption while maintaining high material utilization.
Solution Approach 2:
The patent applies local quality processing by directing specific carbon-numbered fractions to specific processing units based on their properties. C6− hydrocarbons go to gasoline hydrogenation, C7 hydrocarbons to hydrodealkylation, and C8+ hydrocarbons to extractive distillation, allowing each fraction to be processed efficiently without unnecessary separation steps, thereby reducing energy consumption.
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 simplifies the production process, decreases hydrogen consumption, extends catalyst lifetime, and minimizes energy use by eliminating redundant separation steps and integrating xylene production without additional prefraction processes.
Implementation Method 1
supplying a raw material stream to a C6 separation column
Implementation Method 2
supplying an upper discharge stream from the C7 separation column to a hydrodealkylation reaction unit
Implementation Method 3
supplying an upper discharge stream from the C8 separation column to a second extractive distillation column
Data Source
AI summary
Method of producing aromatic hydrocarbons including: supplying a raw material stream to a C6 separation column, supplying an upper discharge stream from the C6 separation column to a first gasoline hydrogenation unit, and supplying a lower discharge stream from the C6 separation column to a C7 separation column; supplying an upper discharge stream from the C7 separation column to a hydrodealkylation reaction unit and supplying a lower discharge stream from the C7 separation column to a C8 separation column; separating benzene from discharged streams from the first gasoline hydrogenation unit and the hydrodealkylation reaction unit; removing a lower discharge stream from the C8 separation column and supplying an upper discharge stream from the C8 separation column to a second extractive distillation column; and separating styrene from a lower discharge stream of the second extractive distillation column and separating xylene from an upper discharge stream of the second extractive distillation column.