Polyisocyanate Purification via Tar Removal and Dividing Wall Distillation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current polyisocyanate production methods, whether using a double-column or single-column distillation system, face challenges in achieving a product with low acidity and minimal coloring while also reducing energy consumption.
Innovation Solution
A method involving a purification process that includes a tar ingredient removal step followed by distillation through a dividing wall distillation column, which reduces energy consumption and results in a product polyisocyanate with low acidity and minimal coloring.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a double-column distillation system is used to remove low boiling and high boiling impurities, then the product polyisocyanate has less coloring, but energy consumption becomes significant and acidity becomes high
Solution Approach 1:
The invention divides the distillation process into two separate steps: first removing tar ingredients, then removing low boiling and high boiling impurities. This segmentation allows each step to be optimized independently, reducing overall energy consumption while maintaining product quality with less coloring and low acidity.
Solution Approach 2:
The invention performs preliminary removal of tar ingredients before the main distillation step. By eliminating tar ingredients first, the subsequent distillation process becomes more efficient, requiring less energy to achieve the desired product quality with low coloring and low acidity.
2Use of energy by moving object
If a single-column distillation system is used to reduce energy consumption, then energy consumption is reduced, but the product polyisocyanate becomes colored and has high acidity
Solution Approach 1:
The invention segments the purification process into distinct steps: tar ingredient removal followed by distillation of low boiling and high boiling impurities. This segmentation enables effective removal of coloring substances and acidity sources while maintaining lower energy consumption compared to traditional double-column systems.
Solution Approach 2:
By performing preliminary removal of tar ingredients which contain coloring substances and acidity sources, the invention prepares the material for more efficient distillation. This preliminary action ensures that the final product has low coloring and low acidity while consuming less energy than conventional single-column systems.
3Use of energy by moving object
If a single-column distillation system is used to reduce energy consumption, then energy consumption is reduced, but acidity becomes high
Solution Approach 1:
The invention divides the purification process into sequential steps: first removing tar ingredients that contain acidity sources, then performing distillation to remove low boiling and high boiling impurities. This segmentation effectively reduces product acidity while maintaining lower energy consumption.
Solution Approach 2:
The preliminary removal of tar ingredients eliminates a major source of acidity before the main distillation step. This preliminary action ensures that the final product achieves low acidity levels while the energy consumption remains lower than conventional single-column distillation systems.
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 effectively reduces energy consumption and improves the quality of the polyisocyanate by achieving a product with low acidity and minimal coloring, specifically an acidity of 50 ppm or less and a hue of 10 or less Hazen units.
Implementation Method 1
in a distillation column, the unpurified polyisocyanate is purified by removing tar ingredients from the unpurified polyisocyanate
Implementation Method 2
a tar ingredient removal step of removing tar ingredients from an unpurified polyisocyanate
Data Source
AI summary
A method for producing a polyisocyanate includes a purification step of purifying an unpurified polyisocyanate, the purification step including a tar ingredient removal step of removing tar ingredients from an unpurified polyisocyanate, and a distillation step of distilling the unpurified polyisocyanate from which tar ingredients have been removed through a dividing wall distillation column.