Dividing Wall Column n-Butanol Purification
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Solution Overview
Problem
Conventional methods for obtaining high-purity n-butanol from crude n-butanol streams require high energy consumption and operating costs due to the need for multiple distillation columns, which also risk forming unwanted byproducts and compromising product yield.
Innovation Solution
A method utilizing a dividing wall column with a specific split ratio of liquid streams between 2:1 and 5:1 in the upper and inflow sections, optimizing the column's design and operating conditions to reduce energy demand while maintaining high n-butanol purity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If all three columns are integrated into one dividing wall column with high bottom temperature, then separation of lighter and heavier components is achieved, but energy demand increases and unwanted byproducts form
Solution Approach 1:
The dividing wall column is segmented into distinct functional zones: an upper section for separating lighter components, a middle section with inflow and offtake sections for high-purity n-butanol production, and a lower section for heavier components. This segmentation allows each zone to operate at optimized temperatures and pressures, reducing overall energy demand while maintaining separation efficiency.
Solution Approach 2:
Different sections of the dividing wall column are designed with local quality variations, including specific tray configurations, packing types, and flow distribution patterns tailored to each section's separation requirements. The middle section features specialized flow distribution to maintain high n-butanol purity with reduced energy input.
2Manufacturing precision
If high bottom temperature is used in the dividing wall column, then heavier components are separated, but unwanted byproducts form and yield decreases
Solution Approach 1:
The process employs dynamic parameter changes including variable temperature profiles along the column height, adjusted pressure differentials across sections, and modified flow rates in the middle section. These parameter adjustments enable high-purity n-butanol production while preventing byproduct formation that would occur at uniformly high temperatures.
Solution Approach 2:
The system incorporates feedback control mechanisms that monitor n-butanol purity and byproduct formation in real-time, automatically adjusting operating parameters such as reboiler temperature, condenser pressure, and internal flow rates to maintain optimal conditions and prevent harmful byproducts.
3Manufacturing precision
If lighter components are withdrawn from the top of the column, then n-butanol purity increases, but energy consumption increases to meet specification
Solution Approach 1:
The system employs partial withdrawal of lighter components through controlled side draws in the upper section, avoiding complete removal that would require excessive energy. The flow distribution in the middle section is optimized to achieve the required purity with minimal additional energy input, using just the right amount of reflux and internal circulation.
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 decreases overall energy demand, enhances operational flexibility, and maintains high n-butanol quality, achieving a yield of over 99% n-butanol with reduced energy consumption and minimizing the formation of unwanted byproducts.
Implementation Method 1
by fractional distillation in a dividing wall column
Implementation Method 2
the liquid stream flowing out of the upper section is collected and divided into a first liquid stream and a second liquid stream, the first liquid stream being fed to the upper region of the offtake section and the second liquid stream being fed to the upper region of the inflow section
Data Source
AI summary
The invention concerns a method for providing a high-purity n-butanol product stream from a crude n-butanol feed stream by fractional distillation in a dividing wall column (102) including an upper section (104), a middle section and a lower section (110), the middle section including an inflow section (106) and an offtake section (108) laterally separated from each other by a dividing wall (112) fixed in the column, the crude n-butanol feed stream being fed to the inflow section (106) and the high-purity n-butanol product stream being withdrawn from the offtake section (108), the liquid stream flowing out of the upper section (104) being collected and divided into a first liquid stream (114) and a second liquid stream (116), the first liquid stream (114) being fed to the upper region of the offtake section (108) and the second liquid stream (116) being fed to the upper region of the inflow section (106), wherein the split ratio between the mass flow rate of the first liquid stream (114) and the mass flow rate of the second liquid stream (116) is from 2:1 to 5:1.