Low-Moisture Terephthalic Acid Wet Cake via Wash Zone
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for producing terephthalic acid wet cakes result in products with high moisture content, requiring extensive drying and increasing production costs.
Innovation Solution
A method involving a product isolation zone that separates a slurry into a mother liquor and a solid phase, followed by a wash zone to reduce moisture content, and an optional enrichment zone to further process the solid phase, ultimately producing a low-moisture wet cake using equipment like vacuum belt filters or rotary pressure drum filters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional vacuum filter isolation techniques are used, then TPA particles can be isolated from slurry, but the resulting wet cake has high moisture content requiring extensive drying
Solution Approach 1:
The patent applies preliminary action by implementing a wash zone before the final isolation step. The wash zone pre-treats the slurry by removing excess moisture and impurities, so that when the slurry enters the vacuum filter, the resulting wet cake already has reduced moisture content. This preliminary washing action eliminates the need for extensive subsequent drying, directly resolving the contradiction between isolation effectiveness and moisture content reduction.
2Manufacturing precision
If conventional isolation and washing techniques are used, then TPA particles can be separated, but production costs increase due to extensive drying requirements
Solution Approach 1:
The wash zone performs preliminary moisture removal before the vacuum filtration step. By washing the slurry in advance, the system reduces the moisture burden that would otherwise require energy-intensive drying. This preliminary action directly addresses the energy loss issue while maintaining effective particle separation.
Solution Approach 2:
The patent extracts the moisture removal function into a separate wash zone that operates independently from the traditional vacuum filter isolation step. This extraction allows moisture to be removed through washing rather than requiring energy-intensive thermal drying, thereby reducing energy consumption while achieving the same isolation objective.
3Device complexity
If simple filtration is used, then the process is simple, but the wet cake has high moisture content
Solution Approach 1:
The patent segments the isolation process into distinct functional zones: a wash zone for preliminary moisture removal and a vacuum filter zone for final particle isolation. This segmentation allows each zone to perform its specific function optimally - the wash zone reduces moisture while the vacuum filter completes the separation - resulting in low-moisture wet cake without requiring complex equipment in either zone.
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 the moisture content of terephthalic acid wet cakes to less than 12 weight percent, thereby reducing drying requirements and production costs.
Implementation Method 1
Vacuum filters typically employ a filter cloth through which the liquid phase of the slurry is drawn using a vacuum source
Implementation Method 2
followed by a wash zone to reduce moisture content
Implementation Method 3
using equipment like vacuum belt filters or rotary pressure drum filters
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Disclosed are methods and apparatus for use in producing a low-moisture carboxylic acid wet cake. Such a low-moisture wet cake can comprise less than about 12 weight percent liquid and can be achieved by washing a carboxylic acid wet cake in a product isolation zone with a wash stream having an initial temperature of at least about 40°C.